How the Earth Was Made: DEADLY Wastelands & EXTREME Phenomena *3 Hour Marathon*

[Music] Earth a unique Planet restless and dynamic continents shift and Clash volcanoes erupt glaciers grow and recede Titanic forces that are constantly at work leaving a trail of geological Mysteries behind none greater than the Sahara Desert the hottest place on the planet a deadly Wasteland That Time Forgot or so scientists believed till they Unearthed a series of startling Clues the fossils of sea creatures freshwater shells buried in sand ancient settlements with human remains clear evidence that this Stark landscape hides a turbulent past one that would alter the course of human history and provide a dramatic new chapter in the story of how the Earth was made Africa's vast Sahara Desert is as big as the United States the sand alone from this giant expanse could bury the entire world 8 in deep it's the largest desert and the hottest place on earth when I first arrived in the Sahara I was just struck by how utterly baren it was it's like the color green was removed from the pallet when they made this place just nothing Grays and Browns and not a scrap of Life Smith's mission is to unearth evidence of what made the Sahara into the Wasteland it is today her investigation begins on the desert's Far Eastern Edge in Egypt not in the Sands of the Sahara but in one of the most epic structures ever built by man the Great Pyramids the building blocks of this ancient wonder house a remarkable clue to the history of this land from a Time long before the Pharaohs even existed so taking a closer look at these blocks making up the pyramids there's actually these gorgeous Marine fossils in here here most obvious are these flat discs up to about an inch wide they're called numes and they're actually single celled [Music] organisms the name nummulites means little coins in Latin they are some of the largest single celled creatures to have ever existed in ancient times these blocks were cut from quaries across the country and dragged to the pyramid site each block weighed 2 and 1/2 tons and it took 2 million of them and over 20 years to build the Great Pyramid and Incredibly up to 40% of each building block is made up of the bodies of ancient sea creatures like these what's even more important about the Marine nummulites is that they date Back 40 million years and they only lived in water it's piece of evidence that this area now desert was once underneath the ocean you think about the construction of the pyramid but not necessarily about what it's made of in these gorgeous fossils the Sahara now is the world's biggest Dust Bowl but the tiny numes fossils suggests that it was once very different that perhaps there could have been water in this Barren Wilderness Smith heads further Inland to investigate this extraordinary idea she travels to a remote Desert Valley near where the pyramid Stones were quarried it's called Wadi al-hitan spread out in the sand lie hundreds of fossils first excavated in 1983 but these are nothing like the tiny nummulites that's a whale so here's the backbone the vertebrae here's some ribs shoulder part of the front Fin and there are the Jaws this guy definitely did not live in a desert this incredible fossil is AD doron an ancestor of modern whales one that died out 36 million years ago so based on the size of these vertebrae and how much of the animal was here it was probably about 21 ft long this guy tells us that we were underwater we were in the middle of an [Music] ocean Wadi al-hitan is Arabic for Valley of the whales this 12mile dip in the landscape has the highest concentration of fossils in the world some were found in the desert floor others in the cliff walls the count so far is 400 almost all are marine animals further evidence that the Sahara was once covered by sea so here we've got the fossil of a baby whale you can see the lower jaw down here with some teeth and the shoulder the backbone some ribs and all curled around actually the tail comes right back to near the head as if finding whales in the desert wasn't intriguing enough there's yet another mystery to be solved a lot of the fossils are a very young doron like this one a delicate mesh of stone helps explain why so many baby whales died in this place wow so finding that whale fossil told us we were in the ocean these rocks actually tell us a lot more about what type of ocean we were dealing with these are all fossilized Mangrove Roots these roots would have been below water the mangrove trees would have risen above it since trees don't grow out of the deep ocean we know that this area was actually under shallow ocean at the time these rocks were deposited something probably that looked like the Florida Everglades where there are mangroves growing now Smith has discovered the shoreline of the ancient sea the shallowness of the water could explain why there were so many young animals here so one idea there's a bunch of these baby whale fossils found in this area and this would have been a shallow protected Bay that maybe the whales came just to birth their young it is absolutely incredible to see a fossilized whale in a place that right now gets less than a millimeter of rainfall a year it's as much convincing evidence for geologic change as I can [Music] imagine the pieces of the puzzle are coming together to reveal the Sahara's watery past so 40 million years ago this desert would have been covered in the middle of this Valley by a shallow bay probably a brilliant tropical blue green color the shoreline would have been off along the horizon some mangrove trees in the shallowest parts of it Inland would have been a vibrant combination of rainforest and swamp land the whales would have been drawn to this ancient Shore because of the plentiful supply of food but their ocean is about to vanish Marine fossils found in Europe and Africa are evidence that this ocean stretched almost halfway around the world and connected Asia to the Atlantic it's called the teus sea and much of the Sahara was submerged under [Music] it the mystery is how and when this Lush Water World turned into the barren Wasteland we see today the answer lies not in climate patterns but in geology the entire African continent is underpinned by a giant piece of the Earth's crust it's called a tectonic plate and 40 million years ago in what is known as the eosine age it was on the move so at w alitan we have whales swimming around in this esine ocean all the while the African plate is moving to the North Africa collides with Europe closing the teth sea but the AFC African plate keeps moving so we uplifted the northern part of of Africa and so the Tey sea recedes and we've got this whole area of North Africa now emerged it's out on land the whales of Wadi alh hatan are cut off and trapped in smaller and smaller pools of water the deadly Sahara has claimed its first victims in the quest to discover the history of the vast Sahara Desert geologists have so far uncovered two important Clues sea fossils in the Great Pyramids of Egypt show these building blocks were once underwater whalebones reveal that a sea submerged much of the Sahara 37 million years ago as the forces of plate tectonics pushed the Sahara out from under the sea it created a tropical swamp in order to figure figure out what made it into the Wasteland visible today scientists have to pinpoint the moment of its birth but the clues to this mystery turn out to be hidden in the last place anyone expected 20 million years ago the Sahara Desert was a lush tropical swamp geologists are now piecing together the story of the next 20 million years to today the Sahara lies in what is known as the desert belt a region of dry air north of the equator here strong winds clear the sky of clouds and dry out the land below it stretches through the GOI desert in China and across the deserts of the southwestern United States the Sahara is the largest and yet geologists know next to nothing about when it was created what we have are just these little bits and pieces these snap snapshots of what the sarea was like because the wind blows away a lot of our record and what isn't blown away is often covered by sand so it's kind of hard to find the Rocks we need to tell the story we're trying to tell one of the few places that shelters a clue to the Sahara's birth is the white desert in this hauntingly beautiful site dramatic shapes have been sculpted out of rock oh this is great let's get that mushroom shape these structures are called yardangs and they are a kind of hourglass that could help measure the age of the desert this rock is another piece of evidence that this desert was once under the ocean it's actually a chalk made up of billions of of little Marine microorganisms these chalks are actually really easy to erode so that's one reason things are so beautifully sculpted by the wind but the wind is a brutal Creator it picks up sand and hurls it at the yardang when when wind scourers or sand blasts the Rocks this is the characteristic shape that we get this mushroom shape narrower in the middle that's because the wind goes faster As you move up from the ground so it can erode harder but it has less sand in it since it picks up the sand from the ground so where we get the most erosion where the rock is narrowest is where we have the best mix of of Fast Wind and the most sand 40 million years ago the top of the yardangs formed part of the solid sea floor but the wind picked up once the Sahara turned to Desert and the process of carving out these shapes began figuring out how long that took could help pinpoint the age of the desert it's hard to say precisely how long it would take for the wind to carve this all out something like this about 15 feet high soft rock you're looking at maybe only tens to a few hundreds of thousands of years but to carve out the whole Oasis depression you've got to need at least a million years but geologists suspect the Sahara is older than a million years in their search for a more accurate date they next turn to its most iconic [Music] feature sand dunes here in the Sahara sandstorms kick up that can last for 4 days the sand is hurled across the terrain over hundreds of thousands of years it accumulates into Dunes that can Tower 50 stories high perhaps these mountains of sand hold the secret of the desert's great age as soon as the climate becomes arage you can start building dunes and if we want to know how long that took we can try and date The Dunes themselves but that's really hard what's hard is that these Dunes are constantly shifting the wind that builds them also blows them away moving them an average of 50 ft a year to get a precise age for the desert scientists need to follow the sand to the end of its Journey course sand travels slowly and doesn't go all that far but the finer particles will actually travel further and so dust sized particles actually can get carried out into the Atlantic the Sahara is the largest source of dust on the planet 500 million tons of it ends up in the Atlantic antic every year some of it reaches as far as Florida and creates spectacular red sunsets but much of it settles on the ocean floor a treasure Trove of information about the Sahara's past what's wonderful about working with the ocean sediments is that they capture everything they they're this very faithful recorder of the sediments that are raining down from the surface in 1995 dominical drilled down into the ocean floor through layers of mud dating back millions of years each layer of sediment is like a time capsule shallow levels show plenty of this dust blown over from the desert so dominical extracted deeper core samples from over a million years ago still there was Desert dust finally he dug down to a layer that was laid down 3 million years ago and there the dust finally stopped it had taken a Voyage to the ocean floor to uncover the turning point from humid tropical landscape into searing desert that's a pretty amazing change you don't think of something as large and expansive and and fixed as the Saharan Desert as being something capable of such profound changes and yet this is what the geologic record was telling us dominical had finally solved the riddle of the sands the Sahara has been a desert Wasteland for 3 million years in the search to discover the age of the Sahara geologists have Unearthed two startling Clues yardangs show that windblown sand has been blasting across the desert for at least 1 million years deep sea cores give a more exact date the Sahara first turned from Swamp to sand 3 million years ago [Music] from that moment on the Sahara became the Searing Wasteland we see today it seemed that geology alone could explain the creation of the world's largest desert then a new radar fitted to the Space Shuttle revealed a striking clue that the desert once harbored a slash of green across its Burning Sands booster ignition and lift off in 1981 the space shuttle made a surprising discovery using a new type of radar NASA took a 30m wide scan of the Sahara Desert the radar pierced the sand to a depth of 16 ft and revealed what looked like a hidden network of ancient waterways crisscrossing the desert this finding stumped scientists 3 million years ago the Sahara turned from rainforest into desert now it seemed that it had been home to a lot of water at some point in the following 3 million [Music] years researchers followed the NASA images North into Tunisia to the edge of a deep depression in the Sahara the sight of their first clue now this is what we're looking for some quite intact shells here this deposit is largely composed of intact shells and these are not shells from the ocean so here we have half of a cadastral glorm shell which is a clear sign of a freshwater lake this is just one example of uh what must be millions of shells we must be somewhere near the shoreline Lake here further shell deposits reveal that this Lake was giant about the size of West Virginia but the shells provide even more remarkable evidence the date when this Lake existed carbon dating puts them at 990,000 years old and leads to one conclusion to have all these shells here we must have had a lot of rain falling in the vicinity of this Lake and a green Sahara scientists fanned out across the Sahara to investigate other satellite images they searched for any dips in its landscape that looked like they once held a body of fresh water so what was really exciting for me about those radar images that are produced by NASA we can link this to the GPS and we're finding evidence of lakes throughout the desert and some of these Lakes are massive three different lakes locations were confirmed by the presence of freshwater shells the series of ancient Lakes were so large they've been dubbed Mega Lakes so this is the far shore of the mega Lake and it was just one of many lakes across the green Sahara when Drake added up the evidence of all the lake locations he uncovered an astonishing fact okay so if this is North Africa here and this is the edge of the Sahara desert so we're here in Tunisia with a mega Lake here and we know there's another Mega Lake here in southern Libya an even larger one here in Chad if they all meet their maximum size they would have covered 10% of the Sahara that would have made them three times larger than the Great Lakes what is now the biggest desert on Earth was once home to some of the planet's largest just bodies of freshh water sudden changes in climate have been connected to everything from volcanic activity to meteors hitting the Earth but climate researcher Peter deenal had a hunch this wasn't the first time it had happened he turned to his Archive of deep ocean cores our approach was to use deep sea sediments as this Contin continuous tapee recorder if you will of past climate change in Africa by looking at the levels of desert dust in cores dating back hundreds of thousands of years he discovered the Sahara had changed more than once when we first collected these measurements I really kind of almost fell back in my chair because what we saw is there are many switches like this in the climate system to explain these regular dramatic changes domical looked beyond the Sahara to the rotation of the Earth itself more specifically small wobbles in the Earth's orbit around the Sun the theory is that the wobble causes the Earth to tilt slightly so the monsoons which drench southern Africa today shift up pouring rain onto the dunes of the Sahara crucially these wobbles occur every 20,000 years so there's this perfect one toone match between when Africa was wet and the stage of the wobble cycle and in this goes back millions of years each time the rain belt moves up the landscape is transformed and the desert turns green to me the the single most impressive thing about Sahara is how small fluctuations in something as simple as a wobble in the Earth's orbit can lead to these really just totally dramatic changes in the climate of a region that's so large scientists now had evidence of how and why the Sahara turned green they knew that giant Lakes covered much of the desert but they had no proof they were connected were these vast isolated rain pools or part of an interconnected river system as suggested by NASA's radar images Nick Drake gets word that in 2009 archaeologists have made an important discovery that supports the river Theory stone tools found not far from the site of the mega Lake in Tunisia the first step is to identify the shoreline of the ancient Lake ah now this is looks good so we got some freshwat mollusks these tiny shells are a good sign of the lake now he searches for what may have been drinking the water when the mega Lake existed we have a what looks like a part of a Jawbone of a small herbivore you can see three teeth running along there some sort of gazelle so animals must have existed here in the desert when it was green okay so we got a a stone tool here it's become blunted and they've retouched it with a lot of very fine flakes off the edge the fact we've got stone tools and we've got dead animals suggests hunting and this was the animal that being hunted and then we've got water so people sitting around a water hole waiting for animals to come to drink and then killing them eating them leaving them behind it's an important find a stone AG tool shows people lived on the shore of this ancient Lake and 990,000 years ago was a turning point not just in the story of the Sahara but in the history of humanity itself we are all descended from one group of people in East Africa the birthplace of humankind sometime between 80 and 120,000 years ago modern humans started the long journey Out of Africa no one knows for certain what route they took the prevailing view is that the Sahara was impassible so humans left East Africa and traveled to the coast then crossed a land bridge into to the Arabian Peninsula but Drake suspects that if the mega Lakes were fed by a river system it would have created a green Corridor Across The Burning Sands so our ancestors could have followed these river systems gone round the Lakes follow the next river system round the next Lake and the next river system and the last Lake and then they've been in North Africa and it would be simple for them to just move out the lake is a good story The Rivers plus the lake is a very concrete story to find proof of his theory Drake heads to one of the few areas in the desert where water still flows an oasis he finds a small spring that shelters a valuable clue cool some great cichlid fish nearly all cichlid fish are f south of the Sahara Desert this particular type of cichlid is the only example north of the Sahara Desert this cichlid Bears a strong resemblance to its closest relative that lives in Lake tanganika [Music] but this lake is almost 3,000 M away on the other side of the Sahara so big question is how did he get it and the most obvious answer is that it swam across the green Sahara modern humans who could live in lots of different types of environments would have assum found it very easy a Dar site easier than this fish these rivers and lakes were not to last the door slammed shut on the green Corridor but scientists now know that the Earth's wobble makes the Sahara like a pendulum it goes from wet to dry every 20,000 years like clockwork the investigation has now revealed two Clues to how these wobbles affected the Sahara freshwater shells dating back 990,000 years prove the desert was once covered by giant freshwater megal lakes a cichlid fish shows the Sahara was crossed by a river that created a corridor of Life across the Sands but scientists still needed concrete information about about how rapidly these changes occurred then an Egyptian archaeologist made a stunning Discovery in the Libyan Desert an eyewitness account of the Sahara's last switch the most dramatic climate change of the last 10,000 years scientists piecing together the history of the Sahara have uncovered a remarkable story 40 million years ago it was covered in ocean 3 million years ago the Sahara turned to Desert since then it has swung between grassland and Wasteland every 20,000 years scientists now turn to the more recent geological past the last 10,000 years to discover how fast this giant desert can [Music] change investigators head to a valley deep in the Libyan Desert [Music] the first clue to unraveling the mystery is a small circle of stones this is essentially the foundation of a Hut it is unimaginable uh to see an actual H structure right there next to what is now nothing Hassan's Discovery is striking evidence of human habitation the uh uh house structure uh consist of this circular foundation with uh upright standing blocks which are taken from the local Bedrock it would have uh made a semicircular structure with probably skins and branches and people would have used that as a shelter Hassan believes these Huts could have housed a small community of around 50 people now he needs to know exactly when they lived here ostrich eggshell beads these little ostrich eggs beads are clearly human handiwork they use the eggshells to make ornamental beads cut into a circle so that a string can pass through so they string these into um bracelets or necklaces the eggshells the beads were made from are also here and provide the next clue the eggshells suggest of course that they were ostriches and that's quite remarkable for this environment to have animals like that this was no nomadic tribe but a settled farming Community rearing animals for food Hassan carbon dated the ostrich eggshell beads the result just 7,000 years ago the deadliest desert on Earth was home to both human and animal life it's dramatic evidence of the last burst of green in the desert a dip in the desert floor provides a clear sign that rain from the monsoon fell here what we have here is the evidence of a deep lake with mud deposited this mud indicates a body of water that could have supported a settlement of people when the lake is deep as we can see from these layers here then there will be a lot of vegetation a lot of animals and people would have a very good time at SES all across the Sahara scientists have excavated similar evidence of Life the remains of elephants and gazel hippos and crocodiles remarkable cave paintings even show people swimming elsewhere human bones have been found carefully buried in what were Lakeside graveyards analysis of these bones reveals they date from between 10,000 and 6,000 years ago the question now for scientists was how quickly the Sahara changed from Bountiful back to bone dry earlier deep sea cores had provided evidence of the moment the Sahara first turned to Desert 3 million years ago and of how since then a wobble in the Earth's axis has made it swing like a pendulum between desert and grassland now climate researcher Peter Deal's on the hunt for the Sahara's last switch from green to Desert one that occurred in the last 10,000 years to a geologist opening this core is like a portal back in time wow that's amazing it's much much redder in the upper part of the core laid down flat every qu in of sediment in the core represents 200 years the color difference in the sediment is subtle but to a practiced eye it's a big clue when we split this core what is surprising about it is that we see this really impressive color change and it's just it goes from this sort of Darker green brown color in this section of the core which comes from the clay minerals that make up the deep sea sediments this bright red sediment actually comes from the wind blown dust that's coming off the Saharan Desert As you move along this core you can see this color maintains itself further up and up in the core so right now we're about 7 or 8,000 years ago boom here is the drawing of the Sahara you can put your finger on it in this core right here at 5 and a half thousand years ago crucially the proximity of these two layers reveals how quickly the switch happened the transition from a very well-watered wet Sahara that was completely vegetated to one that was much much drier that climate transition in this core occurred within one or two centuries scientists knew that the Sahara was an everchanging environment now for the first time they had a sense of just how fast it changed as the Earth wobble shifted the rain belt away the return to Desert was Swift and deadly these transitions would have happened almost on a generational time scale that one generation after the next after the next would have realized that where they're living is no longer sustainable high above the ruins of the lake settlement fkri Hassan has discovered a cave he believes was important to the Saharan people during this Sudden Change in climate perhaps it holds eyewitness Clues to what happened when I first uh came into the cave the sand was as high as this level and I had to crawl in because the sand had covered the whole area well this wind blown sand cannot form when the desert is green buried in the sand was the first clue some perfectly preserved animal droppings so these animal droppings only tell us about the climate at the time but they also are excellent materials for radiocarbon dating which allow us to date the final event of the try of Sahara these goat droppings covered in sand reveal a Time when a farming Community was overwhelmed by desert hidden in the back of the cave is a clue that confirms people sought shelter here the cave has a very interesting feature which is the prince of hands so this is excellent uh evidence of the people that lived here the next clue suggests that around them the Sahara was beginning its Relentless transformation into desert well here we see a very interesting drawing with these long uh lines this represents um a cloud with rain coming down rain was becoming very scarce at that time and they would have used this cave to pray for rain but with the monsoon now several thousand miles south their pray prayers could not be answered uh well this cave must have been a very important secret place for these people at a time when things were getting really bad eventually despite these rituals the force of this change was so great they had no choice but to leave here in this cave we have the sand and we have the handprints which is the last message left by the Saran population the story of this cave started with a tilt in the Earth's axis that stopped the rain falling on the Sahara what must have seemed like a NeverEnding drought would in just 200 years turn a gentle fertile region the size of the United States into a brutal searing Wilderness the Wasteland we see today this would be the biggest environmental upheaval of the last 10,000 years those that could must have migrated East to their closest source of water the Valley of the Nile a beacon of green in the vast desert this Exodus had a surprising outcome the death of one culture 5,500 years ago would lead to the birth of one of the most advanced civilizations on the planet it was a drawing of the desert that led to this great civilization people came from different places in the desert establish their Villages and within a very short time they began to have the basic ingredients for the rise of Egyptian civilization so climate change in this particular case um stimulated uh one of the most spectacular events in world history the investigation into how quickly the Sahara returns to Desert has uncovered two striking Clues ostrich eggshell beads show people and animals inhabited a green Sahara just 7,000 years ago ocean sediments show that the Sahara returned to Desert at Breakneck Pace in just 200 years the next wobble in the Earth's axis is set for 15,000 years from now only then will the Sahara turn Lush and green again but now modern technology is finding ways to speed up that process the investigation into the Sahara desert's eventful past now moves to the last 100 years in 1956 French Prospectors discovered vast reserves of oil in the Sahara this triggered an oil rush that led to drilling across the desert then they struck something unexpected under the sand huge quantities of fresh water it seemed the Sahara had another secret to reveal so this is a classic pumped well drilled for irrigating the fields and the water is actually pretty hot which means it's coming up from a considerable depth the deeper the well the hotter the water water from Wells in the Sahara can reach up to 150° F such a high temperature means the pump is drawing water from far enough underground to be warmed by the Earth's internal heat so pumps like these can bring up water from 3/4 of a mile underground or even deeper with no rain for years at a time this water must be coming from somewhere Smith spots another clue actually when I look at the surroundings of the well I can see some orangish red Iron staining this is hematite a mineral that is typically found in water that's been underground for a long time combined with the temperature this points to some kind of deep Reservoir scientists say that astonishingly great quantities of water lie under much of the Sahara the key is in the Sandstone sandstone is made from layers of sand compacted into rock over millions of years so what's really incredible about Sandstone like this is just how good it is at holding water and that's because there's a lot of poor spaces between the sand grains that are actually really big if I pour some water on this rock just like would have happened when it rained over the Sahara it soaks right in scientists now know that every 20,000 years a wobble in the Earth's orbit shifts the monsoon North so rain Pours Down onto the desert much of that rain that fell over the Sahara is now stored underground it's called the Nubian sandstone aquafer and like a giant Subterranean sponge it sits below Egypt Libya and Sudan though there's nothing but sand and rock on the surface under the ground ground beneath my feet is as much water as there is in the Great Lakes the presence of a reservoir even one deep underground is surprising given the Sahara's searingly hot temperatures in 1922 in neighboring Libya the Mercury touched 136° a record still not beaten but ironically the water is protected by the desert itself layers of clay encase the Sandstone the clay keeps out the harsh Sun it also acts as a sealant trapping the water within the rocks and creating pressure fault lines in this clay are the source of the desert's famous oases so this is a natural spring where water is coming up from the Newan aquifer under its own pressure this is actually fossil water it's been dated to be up to a million years old this reserve of water is a legacy of the Sahara's lush green past the remains of its giant lakes and [Music] rivers and this is just one aquafer scientists are now using ground penetrating radar to locate and map other aquifers across the Sahara they hold the promise of even more fresh water this new technology offers hope that the desert May once more turn green reclaimed for agriculture and farming if all goes to plan eventually there will be 200 Wells here but drilling could prove a short-term solution this is fossil groundwater it's not being renewed So eventually you're going to run out water that supported prehistoric occupants in the area and accumulated over a million years is potentially going to be gone in less than a 100 once the underground water dries up the desert will have to wait another 15,000 years before once more the Earth's wobble turns it green again the mystery of what created and changed the Sahara Desert has revealed a turbulent past whalebones in the desert show that 40 million years ago the Sahara was a seabed deep ocean cores containing wind blown sand reveal the date it dried up 3 million years ago freshwater shells show that 990,000 years ago a wobble in the Earth's axis created giant lakes and rivers and turned the Sahara green every 20,000 years ostrich eggshell beads indicate that just 7,000 years ago the Sahara enjoyed its final burst of life before returning to Desert the secrets of the Sahara have finally been revealed this desert is not a static Wasteland it's Dynamic and full of life capable of blossoming into lush green terrain this vast Majestic land continues to shift change and evolve much like the Earth itself Earth a unique Planet restless and dynamic continents shift and Clash volcanoes erupt glaciers grow and recede Titanic forces that are constantly at work leaving a trail of geological Mysteries behind this episode explores Everest the highest mountain on planet Earth in order to unlock its Secrets a daring mission is undertaken to bring back rocks from the summit this journey of Discovery into the formation of Everest will uncover ancient fossils hidden crystals epic weather and immense structures etched into the mountains all part of the incredible story of how the Earth was made the Himalayas stretch 1500 miles across Asia they're home to 14 of the tallest mountains on the planet and one rises above all others Everest at 5 1/2 miles tall Everest is the highest mountain in the world in order to figure out how this Giant mountain was made geologists need evidence Rock samples from Everest It's A Dangerous Mission and only a few people are willing to undertake it Kenton cool is one of the world's best high altitude climbers and he will embark on this geological mission to the summit of Everest his instructions from geologists are to collect Rock samples from three places one from the summit and two from lower down these incredibly rare samples will give investigators crucial evidence Kenton is at Everest Base Camp pitched on Jagged rocks at 17 1 12,000 ft this camp is over 3 mil above sea level sorting out the last of the items I need to take on my stomic push and uh I've just been to collect a load of Ziploc bags which I hope to put all the samples in over the next 5 days he will climb 12,000 ft the equivalent vertical height of eight empire state buildings Kenton starts his mission from base camp he negotiates the kumbu icefall a frozen River with crevasses thousands of feet deep it's a treacherous Ascent as all this glacial ice is constantly moving and looming ice towers threatened to collapse Kenton now has the most dangerous section ahead of him at 21,000 ft he is already higher than Mount McKinley he has a sheer ice climb up the side of Everest winds reach speeds in excess of 100 mph and temperatures drop to -40° since leaving base camp Kenton has climbed for 4 days at 266,000 FT he reaches the point which joins Everest and its neighboring Mountain ly so hey this is South Coal one of the highest camps in the world 7,950 M so high that nothing can actually live here from this Camp Kenton will leave at 3:00 a.m. climb through the night and aim to arrive at The Summit in the morning pitch black that's three in the morning timing is crucial and the weather must be ideal the window for Ascent is narrow there are only around 12 days of the year when climbers can make it to the summit Kenton must take this opportunity he now Ventures into what climbers call the death zone oxygen is needed to make the climb as the air is three times thinner than its sea level one in 10 people die climbing Everest and most fatality ities occur during this final stage one more Kenton finally reaches the top of Everest 8,850 M we are the highest people in the world this is the view from the highest place on planet Earth for most climbers the Summit is the ultimate goal but for Kenton his mission has only just begun he heads just below the summit to find an exposed outcrop of rock kenton's first sample is a gray Limestone it's soft and easy to break off this is a sample of the highest rock in the world [Music] one down two to go Kenton descends further to collect the next sample just below the summit The Rock changes climbers call it the yellow band due to its distinctive color the rock is dramatically different from the summit much harder and yellow in color this is a leg of marble all right there we go this is off the yellow band all right so that's that that's a yellow band we've collected sample from here it's not be very easy we're going to out of here it's beginning to snow but he has one more to go Kenton starts the long descent to where he'll get the next piece of evidence he enters into the Western a huge U-shaped valley which has been carved by the kumu glacier a frozen River of ice that has relentlessly pushed downward over the past million [Music] years Rock and debris in the glacier have ground away at the Rock underneath revealing the base of Everest Kenton needs to take his final sample from this area of distinctive White Rock Granite so here we are in the Western Kum on ever about 6,400 M I'm actually stood underneath one of the easier outc crops to get to this is a big sort of granite Cliff uh above me this White Rock is full of crystals it's extremely hard and different again from the Summit Limestone and the marble yeah we got quite a nice sample of the Granite there with the three precious samples safely packed away Kenton takes them to the University of Oxford here they will be analyzed by the world's leading Authority on Everest Mike surl so Mike this is your summit Rock now that is from the top of the top of the world well this sample kenon is probably one of the most important samples of the whole Expedition so it's literally worth its weight in gold geologically this came from the summit of Everest right there the next rock down that you collected was from the yellow band and even further down is another rock a granite almost a complete picture of Everest that's right yes fantastic these three rocks are the major compon opponents which make up Everest all that effort to get up to the summit was I can tell you was absolutely worth it to get this SLE good good I hope so so the next step is we want to find out what's in it the summit rock is cut into a thin section so thin light can pass through it okay let's have a look at this slide from of a limestone that's from the Summit of Everest the highest rock sample in the world reveals its secret oh that was interesting what's that we've got a section here through a kinoid uh Stam acoid is a Mily from fossil records the section can be dated it is over 400 million years old the sea ly is evidence that the summit Rock of Everest was formed in an ancient marine environment so from seeing this evidence we can categorically say that this rock would have started life at the bottom of the sea floor and then I've collected it from the very very top of the world from the summer of Everest itself that's that's just amazing but a mystery is revealed how had rock with Marine fossils in it ended up on the top of Everest the mission to collect Rock samples from Everest has uncovered two Clues as to how it Formed samples show that the mountain is made from three distinctive types of rock rock from the summit of Everest contains Marine fossils proving its started life on the bottom of the sea to figure out how seafloor came to be on top of the highest mountain in the world geologists need to find evidence that is millions of years old going back way before the Himalayas were even formed 400 million years ago no trace of the Himalayas existed the sea liily now fossilized on the summit of Everest is proof that there was once water where now this great Mountain stands but to figure out whether this was just a shallow Inland sea or a great ocean geologist Mike surl travels to the Himalayas he begins the investigation at the garola river it flows down from the high Himalayas and carries with it an intriguing clue The Rock I've got in my hand at the moment may look a bit boring and insignificant it's just a pebble taken from the river but it's actually a key clue as to the formation of the Himalayas and the evolution of the Rocks it's almost by Magic but when you smash a rock like this open what it reveals inside is an absolutely beautiful fossil and this fossil is what we call an ammonite this ancient creature is part of the squid family it's proof of a complex ecosystem found in a deep ocean giant squids swimming around in the seas that once lay between India and Asia and this is some of the key evidence that we've got that there was a major Ocean between the continents but to find marine fossils in the high Himalayas and on the summit of Everest some immense geological Force must have pushed the ocean floor upwards above the water figuring out how this happened has taken geologists over 100 years the first lead in this investigation came from an unlikely place Antarctica in 1910 the renowned Antarctic Explorer Robert Scott began his ill fated expedition to the South Pole after reaching the pole Scott and five of his team died when the bodies were discovered among their equipment were carefully wrapped and labeled fossils the fossils were part of an ancient plant called glossopteris and specimens are preserved at the British Antarctic Survey GIS is type of plant known as seed Fern and from many different lines of idance such as roots and leaves and preserved trunks paleontologists think that glop are actually um a type of tree soon this humble tree fossil was found across the globe in India South America Africa Madagascar and Australia geologists now had a puzzle how had this one species of plant spread between continents separated by thousands of miles of ocean theopus is a very important fil because it could not have dispersed over vast distances it couldn't have been dispersed by the wind or by birds across oceans if glossopteris couldn't cross oceans then scientists were left with one conclusion when these trees were alive 250 million years ago the continents were all joined together they were part of a supercontinent geologist called gondwana land glossopteris was able to spread across this ancient land mass but then gondwana was split up by violent tectonic forces which pushed the continents apart and 80 million years ago India broke away from the supercontinent it traveled North and eventually smashed into Asia to get the full picture geologists now knew they must get an exact date for this Collision once again they turned to Marine fossils we know the age of collision of India and Asia from several factors but the most important one is the age of the youngest Marine fossils that are preserved along that Collision belt and the age of those fossils is very precisely dated 50.5 million years 80 million years ago India left gondwana 50.5 million years ago it hit Asia India traveled 4,000 m in just 30 million years very fast in geological time India was drifting northwards across the Indian Ocean at very rapid plate tectonic speeds and we're talking here between 10 and 12 in per year which is very rapid it's this speed that goes some way to explain the unique size of the Himalayas because as with any smash the faster the Collision the bigger the wreck the investigation has now uncovered Clues to prove India and Asia were once separate ammonites are evidence that an ocean once existed between India and Asia glossopteris fossils prove that India was once part of a supercontinent called gondwana land the next part of the investigation is to discover how this InterContinental smash gave rise to the tallest mountain in the [Music] world geologists piecing together the story of how Everest was made have shown that 400 million years ago a wide ocean existed where the Himalayas now stand India was part of gondwana land until 80 million years ago when violent tectonic forces threw the planet into turmoil and split up this ancient land mass pushing India northwards 50 million years ago India collided with Asia and for the next 30 million years this InterContinental smash began to shape the world's highest [Music] mountains traces of the first stage in this process can still be seen in the Himalayas today the best way to spot them is from the air the C of high Himalayas are so incredibly accessible I mean just look at that view out there there's a sea of mountains all of them are over 20,000 ft there must be hundreds of them and those are impossible Mountains for a mere mortal to climb this is geology on a massive scale the distinctive formations come into view huge folds of rock clearly seen on the sides of the mountains all of these folds that we seeing right here on DOI and Tuk JP were formed during the first part of the Himalayan Mountain building process so when India first collided with Asia the first thing to happen was that the northern margin of India started buckling and folding and those folds are just so spectacular when you look out the window here they're just unbelievably [Music] impressive like a giant train wreck India collided with Asia the land and ocean floor that lay between literally folded up under the enormous pressure but folds are only part of the story alone they don't explain the himalaya's vast size back on the trail surl is on the hunt for further Clues this is what makes the whole trip really worthwhile we just spent 5 days hiking waking up through the jungle through the forest pouring with rain and up there finally are the high Himalayas I just love those mountains look at those Peaks up there they are absolutely beautiful sirl points to an intriguing giant scar which is revealed on the face of one of the mountains it's evidence of the next dramatic phas days in the building of the Himalayas this is a sketch of what we're actually seeing in front of us with the big mountain of do leiri here and the big folds on the peak of tuche to the right with this enormous great fault that is magnificently exposed right along the base of DOI coming right down to the calig gandaki river valley at the bottom the fault is a fracture running right through the mountains well the first step in deforming the Himalayas is that the rocks are folded into giant folds and when that process continues The Rock can no longer fold so they become overturned folds and when the process continues even further that overturned fold actually moves along a very discrete fault plane and that's exactly what we see throughout the whole Himalayas so rocks are formed by f holding and thrusting rocks can only be bent so far once Rock has been bent Beyond its limits it breaks and causes a fault the process of faulting puts different rock types one on top of the other Faults Are ju depose rocks of two different types so the big huge fault that cuts through the tops of the High Himalayas the top of Everest are rocks that are putting limestones over [Music] marble this is exactly what was revealed by kenton's Rock samples from Everest limestones at the summit lying on top of the hard marble of the yellow band evidence that the top of Everest was initially created by folding and faulting but this only explains part of the story to create a mountain the size of Everest geologists knew that there must have been another more powerful mountain building process at work Clues to exactly what this process was can be found in the cicola river this river is a giant garbage shoot bringing all these Boulders eroded off the high Himalayas to the north and sweeping them down in great floods down to the plains of India to the South so this is a great place to come to sample all the rocks that make up the high mountains to the north as any detective knows some of the best finds are made by sifting through garbage this time it's garbage from the Himalayan Peaks this is exactly the rock I've been looking for this is a beautiful example of a kite nice which is composed of these beautiful blue bladed crystals of kenite kenite is a gemstone and it gives a clue as to how these rocks formed this mineral is very specific to a geologist and it tells us that this rock has been buried to depths of about 30 m or more under high temperature and high pressure Rock was not only pushed upwards by the Collision but also down towards the Earth's molten core heat and pressure changed the Rock and formed kyite crystals another Boulder in the river gives a further clue as to what was going on at these great depths this White Rock is a Himalayan granite and most of the highest peaks of the Himalayas are actually formed of this rock and of course the base of ever is formed of exactly the same the presence of these white streaks tell me that this rock was actually partially molten at the highest temperatures during the Himalayan Mountain building process The Rock was pushed so far beneath the earth's surface that it reached heat in excess of 4,000 de F and began to melt once it was molten it was able to move and Flow well you can think of the Himalayas more as a conveyor belt system taking Indian plate rocks pushing them down deep in the crust they are altered by Heating and increasing pressure eventually melting to produce granite and then forced back up to the surface along these giant Shear planes 20 million years ago this amazing conveyor belt system was at work as India pushed northwards a liquid band of buoyant Rock was forced towards the surface and cooled forming a solid layer of granite a process called Channel flow granite a very buoyant rocks so when they're formed by partial melting of the crust normally they're pushed up through the crust to form mountain ranges like you see in the Sierra Nevada or yosimy national park for example the Himalayas are different these granates are flowing almost horizontally from where they formed the southern part of the Tibetan Plateau to the form the high peaks of the Himalayas and it's this conveyor belt system that keeps the high Himalayas actively uplifting to this day the mountains were repeatedly jacked up to Epic Proportions it's this unique process which accounts for the himalaya's immense size Kenton CO's mission to Everest uncovered an unusually thick band of granite proof that Everest's awesome size is due to the process of Channel flow geologists investigating how Everest was built have discovered folds and faults proof of the initial mountain building process White Stripes of granite indicate The Rock was melted at over 4,000 de forming a giant conveyor belt of mountain building power but the Himalayas were set to become part of a geological battle between catastrophic forces and Powers which would challenge the very height of Everest 400 million years ago the Himalayas started out life at the bottom of an immense ocean 50 million years ago they were thrust into the skies as India smashed into the Asian land mass since that time tectonic forces have created the tallest mountain in the world but what of the immediate future will Everest continue to rise or will this giant soon be cut down John galleta is investigating whether the processes which built Everest continue to this day he has traveled to the remotest regions of Nepal and India setting up GPS stations which he hopes will provide him with the answer all right come as far as I can by a car and I've got a three-hour walk straight up the [Music] slope Namar just like a GPS in a car this station is able to pick up signals from satellites and monitor any movement of the ground the GPS station has been uh operating continuously for The Last 5 Years so every second of every day of every month of every year it's taking a data sample and what it's looking for is changes in the position of where this station is but how it's moving the velocity of this station believe it or not and even changes in velocity the readings from the GPS show that India is still moving about 2 in every year 50 million years after its initial Collision it is still on its Relentless Journey northwards pushing underneath Asia and as it does so Everest continues to be pushed higher but there is a dark consequence to this mountain building earthquakes so what's going on here in the Nepal Himalaya we've got the Indian tectonic plates sort of ramming into Asia in this case India is is losing out it's it's being forced under Asia but it's unfortunate that they're locked frictionally and eventually over the course of hundreds of years that strain is accumulated and then released suddenly in a giant earthquake the Himalayas have seen 15 major earthquakes in the past 100 years the most recent to hit was in Pakistan October 8th 2005 the Quake devastated the region gla's readings show that another earthquake is on its way catmandu the capital of Nepal lies in the center of the danger zone when that earthquake happens not not if when that earthquake happens it's going to be several minutes of of Terror there'll be strong shaking you know in kandu there'll be just collapsed structures you will see landslides on on all these mountains it's going to be complete Devastation 26 million people in in Nepal 50 million people along the whole Arc of the of the Himalayan range all of these people will be affected these devastating earthquakes are the result of a very active Mountain belt further evidence that Everest is being actively pushed upward but there is a second Force at work in these mountains erosion there's a constant battle going on in nature here between the uplift of the Himalayas and the down cutting of erosion erosion in the him alas is ferocious a clue as to the reason why lies in a small village 300 Mi east of Everest cherapunji [Music] it's the wetest place on planet Earth averaging over 432 Ines of rain each year this place is 12 times wetter than SE battle and the reason for all this rain the monsoon the Indian Monsoon system is a almost unique system on the planet and the ultimate driving force is the high mountains and the high Himalayas and the Tibetan Plateau which is by far the largest area of high elevation on the planet today and that causes this massive high pressure system during the summer months which results in the sucking in of all the warm moist air from the Indian Ocean this seasonal weather system blows in across India clouds build and Rise as they hit the high mountains and form heavy rains which fall across India those rains reach their maximum on the southern slopes of the Himalayas during the heights of the Summer monsoon some of these Rivers are able to rise by 20 or 30 ft in one storm so where I'm standing now the levels of the river will be way up over here each year 264 cubic miles of fresh water enough to fill Hoover Dam's Lake me 30 times over Pours Down the slopes of the mountains this water feeds some of the largest rivers in the world the Ganges the Indus the iraa and the yangi the Himalayas are the water tower of Asia supplying fresh water to a fifth of the world's [Music] population but all this water is having a dramatic effect on the mountains fast flowing Rivers cut steep-sided Valleys High in the mountains rain turns to snow feeding glaciers which carve into the upper slopes all these forces are at work today wearing away at the Himalayan Peaks because the monsoon is so powerful geologists suspect that Everest and the Himalayas are being worn away perhaps more quickly than any other Mountain belt in the world since 2004 a powerful new technique has emerged that can actually measure how fast a mountain is being worn away it uses high energy particles from space at present we're all being bombarded by cosmic rays they come from distant parts of the Galaxy when these particles hit a rock surface a chemical change happens it's like a kind of cosmic sunburn erosion from rivers and Glaciers expose Rock surfaces to these cosmic rays and just like sunburn the longer the rock is exposed the greater the damage to its surface by measuring the amount of cosmic sunburn in the Rocks geologists can figure out how quickly rivers and Glaciers are cutting into the mountains but working this out needs very precise science the concentrations that we're trying to measure are so small they're equivalent to putting a pinch of salt in Olympic size swimming pool and measuring one or two grains of that salt after years of research Owen has discovered the maximum speed of erosion 1.1 in per year that's six times faster than the Rocky Mountains and faster than anywhere else on the planet all mountains suffer from erosion they're built up by tectonic forces and erosion wipes them down again the Alps the Rocky Mountains the Andes all have erosional potential but nowhere has such huge erosional potential as the Himalayas the erosion here is far greater than anywhere else and the main reason for that is the Summer monsoon the battle in nature between uplift and erosion continues but the question remains which one is winning is Everest shrinking or growing in 1999 a team of geologists set out to answer this question they placed a small GPS station near to the summit of Everest after 2 years of monitoring the team had their answer Everest was in fact still growing a quar of an inch every year the world's tallest mountain is still getting taller the investigation into the growth and movement of the Himalayas has revealed the following evidence GPS data shows a very active Mountain belt that is still uplifting cosmic ray dating proves that the Himalayas are being eroded faster than any place else on Earth geologists now have the tools to predict Everest future it and the Himalayan mountain chain will continue to rise aided by new technology discoveries are still being made in the Himalayas and recently one reveals that the rise of these mountains was so immense that it might have changed the very course of Earth's history and plunged the entire planet into a deep freeze Everest 50 million years years in the making today the Himalayas stand as the biggest highest and most active mountain range on the planet they are mountains of superlatives the deepest valley falling over 20,000 vertical feet the highest Plateau the longest sheer rock face hundreds of Peaks higher than anywhere else on Earth and many have never even been named the formation of the Himalayas has changed the entire landscape an epic Evolution from Ocean to immense mountain range and created one of the world's most important weather systems the monsoon which supplies fresh water to 1if of the world's population the Himalayas and Tibet a really exciting place to work for a geologist this is because it's such an active and dynamic environment not only that it's a very important area climatically scientists investigating the Himalayas have uncovered some surprising results discoveries which would suggest that the rise of the Himalayas might have had an impact on the climate of the entire planet the discovery came about almost by accident while scientists were studying a process called chemical weathering every time it rains carbon dioxide in the atmosphere dissolves to form acid rain when the rain falls it eats away at Rock surfaces this weathering process takes CO2 out of the atmosphere and locks it away in the Rocks if that rock is interacting with the atmosphere it pulls down carbon dioxide and that leads to a negative greenhouse effect if you like an ice house effect so you get more weathering you pull down the carbon dioxide out of the atmosphere and that leads to cooling the more CO2 there is in the atmosphere the warmer the global temperatures take CO2 out of the atmosphere and temperatures are reduced then scientists discovered a major coincidence the dramatic rise of the Himalayas over the past 20 million years coincided with the gradual fall of global temperatures which led to the start of the last major Ice Age the pieces of the puzzle fell into place as the Himalayas uplifted they had acted like an Ever growing giant sponge and absorbed massive amounts of CO2 from the atmosphere the uplift of the Himalayas and Tibet leading to the draw down of carbon dioxide from the atmosphere by these weathering processes was probably one of the major factors in leading to the cooling that culminated in the Ice Age that started about 2 and a half million years before present a cooling effect which was so intense that 2.5 million years ago it contributed to a global deep freeze an ice age that affected the entire planet and had a dramatic impact on all life on Earth and geologists are sure that the Himalayas will continue to exert an immense influence on our planet as these mountains are still growing as India pushes northwards under Asia the building cycle continues more Mountains will form over the next 10 million years 300 mil of land will be forced under Asia the entire range will grow even taller out in this vast Wilderness of icy peaks geologists are still making discoveries for for geologist is exciting in terms of the science because you get to areas where few geologists have been before as the research continues at Everest and across the Himalayas it is a wonder what SE Secrets they might tell us in the future the evidence for Everest's incredible geological Journey has been revealed ammonites evidence that an ocean once existed between India and Asia and that the continents collided 50.5 million years ago folds and faults proof of the initial mountain building process Granite evidence of a giant conveyor belt of mountain building power which pushed Everest to its immense height GPS data reveals that the Himalayas are the most active mountain range on the planet and Everest is still growing Everest today stands as the highest place on planet Earth but in millions of years to come there will perhaps Be Another Mountain big enough to challenge this giant living proof that the Earth is never at rest Earth a unique Planet restless and dynamic continents shift and Clash volcanoes erupt glaciers grow and recede Titanic forces that are constantly at work leaving a trail of geological Mysteries behind behind this episode Journeys back through time to explore how ice has shaped modern North America geologists discover how America's temperatures plunge to an average of 26° Fahrenheit all year round how a wall of ice eight times the height of the Empire State Building covered much of North America and how ice created some of the country's most stunning GE logical wonders a deep Frozen episode in the continuing drama of how the Earth was [Music] made one awesome physical Force has had more impact than any other on the shaping of modern North America the dynamic Unstoppable power of ice over millions of years ice sheets a mile or more thick have decapitated the continent's mountains and Damned and diverted its rivers but the full extent of how ice has carved and sculpted the landscape of the US is only now becoming clear as scientists investigate the overwhelming geological impact of America's Ice [Music] Age for centuries America's early geologists were puzzled by mysterious marks etched into the Bedrock of much of North America and by Lonely mounds of rock randomly scattered across the land many believed such features were evidence of a massive flood in the long-distant past but then in 1847 a newly appointed Harvard University Professor came up with a radical new idea geologist Louie ages compared North America's landscape and rocks with the geology of mountain glaciers in his native Switzerland and he built on theories he had developed in the Swiss Alps a decade earlier to declare that North America had once been buried deep under ice a 's work at Harvard made him world famous in his day but the final proof of his Ice Age Theory had to wait until the 1950s when new evidence came from the seabed of the Atlantic [Music] Ocean that evidence is still stored to this day in this refrigerated laboratory at Miami University these thousands of plastic tubes offer science s a unique window to look back at what the weather was like on the ancient Earth these records which you see in this room here basically are the primary information we have now about the climate changes we have had over the last 2 million years so these are really were the starting points that open people's eyes about uh changes which occurred during racial periods the mud cores were collected by oceanographer Cesar emiliani the deeper he drilled the further back in time he went and the older the sample he pulled to the surface these are cores of deep sea mud and within the mud are small organisms which record the temperature and the salinity and the other conditions which were prevalent when that organism lived those tiny undersea creatures are called forom manifer their chemical makeup varies depending on the temperature of the water in which they grow so the seab bugs in different layers of mud act as Tiny thermometers recording how hot or cold the Earth was at different times in its past they revealed that just over 2 million years ago the average annual temperature across the lower 48 states was around 56° F about 3° warmer than it is [Music] today then the temperature regularly started crashing below zero and staying there for month after month huge changes happened with what in geological terms was astonishing speed within 10,000 years the year round average temperature bottomed out at just 26° F the same as the average winter temperature in Chicago even today scientists are uncertain what caused the temperature to drop so quickly variations in the Earth's orbit a change in the tilt of its axis and even the creation of the Himalayan Mountain range are all prime [Music] Suspects but one thing is certain with sub-zero temperatures all year round Snow Never melted a major storm can drop more than 40 million tons of snow the ever increasing weight compacted down into thick layers of solid ice America's Ice Age had begun an important clue to what happened next lays in a rock quarry just outside the town of Champagne Illinois in quaries like this rocks normally hidden deep underground are exposed by commercial blasting that gives geologists the chance to examine rocks they could never normally see this rock in this Sandy cobbly bank is a very important and significant ific piece of evidence for the history of North America during the last several hundred thousand years it's what we call an erratic it's a rock that doesn't belong here now this rock traveled several hundred miles uh to get to this place in fact this is a type of granite usually found in Canada somehow it is traveled to Illinois but it's not unique all all over the northern states rocks of all shapes and sizes have been dumped in places they don't belong this one the size of an elevator is in Central Park New York it was originally from New Jersey and this one the size of an automobile and weighing just as much comes from 500 M north of Ontario scientists have figured out just how such huge rocks must have been transported over such long distances the ice sheets which built up 2 million years ago began to move flowing as huge glaciers across the northern us some of the very large rocks can be literally Frozen on and plucked off from the rock where they came from and transported right into the glacier and moveed that distance of hundreds of miles in the glacier like a conveyor belt out to where we finally find it on the landscape or in and outc crop like this the investigator's next challenge is finding out just how far the ice flowed and for that task they are taking to the air in the early morning light brown spots a mysterious small hill standing out from the flat Illinois plain stripped of its camouflage layer of trees the shape of the Hill tells Brown the secrets of its creation this gently rolling landscape extends for about 400 miles we look at the landforms and how they're shaped and so we can use that to unravel the history of of the Ice Age the land form Brown is studying is a mound of rubble that geologists call a morine it is an accumulation of debris that a glacier has plucked up from the earth dragged along and dumped at the front edge this hill marks the spot where the glacier finally stopped flowing Southward geologists all over the US have recorded the positions of other Marine Hills helping them map out precisely how far North America's ice sheets spread nearly 2/3 of the North American continent was buried under [Music] ice so far scientists studying America's Ice Age have discovered tiny temperature recording seab bugs in Ocean sediment showing the US chilled down 27° at the start of the Ice Age and morine hills of rock and debris mapping out where the ice sheets halted [Music] but the Frozen chaos did not stop there the challenge now facing geologists is figuring out how ice created some of modern North America's most famous [Music] features 2 million years ago temperatures fell and massive ice sheets spread out as glaciers across much of North America geologists set out to discover what the moving ICE did to the underlying land everywhere the ice had flowed investigators discovered the same puzzling feature lines of stones all laid out in the same particular way this is a really good example of a pavement of stones this concentration of small rocks and cobbles that are collected here in a line it's just one one stone or two stones thick scientists realize that the stone Pavements must have been laid down at the base of a glacier and even the toughest rocks had scratches and grooves carved into their surface Glacier carries along other fragments of rock and at us doing so it scratches polishes and creates grooves in the rock called striations those scratches offered vital Clues to help uncover the history of how the Ice Age changed America we can measure their orientation and they can tell us something about the direction of Ice Flow so I'm aligning my compass parallel to the striations on this rock the compass tells me that the ice is Flowing from about the Northeast from this direction to this direction but other scratches on rocks found all over the Northern parts of the US run in puzzlingly different directions these ice scraped rocks in New York's Central Park show scratches made by a glacier that arrived from the Northwest there's only one explanation for the different ways in which the ice appears to have moved the scratches were not all made by a single ice sheet as first thought but by many different ones this phenomena of advance and Retreat and changing of that landscape happened many times not just once but many times everywhere the ice flowed it marked the underlying rocks that's given investigators plenty of Clues to help establish a pattern of ice movements but understanding the full picture involves a lot of geological detective work this of glaciation of advance and Retreat leaves an incredibly complicated record for us to solve we only see fragments of this puzzle in any place we look at like in a quarry and so it's a great challenge for us to figure out how each of these fragments fit together the ice changed the existing conditions on the landscape those changes include erosion of glacial debris in a way that changes the whole way these areas look grinding over the landscape at speeds of around 2 ft per day the massive glaciers diverted the course of ancient Rivers even the mighty Mississippi was no match for the ice it moved the position of the Mississippi River the Mississippi River used to flow through the middle of Illinois a glacier Advanced across the state and created an ice dam across the course of the Old River a huge Lake grew at the of the ice eventually overs spilled and cut a new River Channel 80 Mi to the [Music] West the same course that it follows to this day and when the ice sheets melted away their impact on North America was almost as great they produced immense floods of water which all had to drain away somewhere it formed a complete completely new landscape with new river valleys new channels new places where rivers flow completely rearranging the character of the existing [Music] landscape where rocks were soft or weakened by faults the glaciers had carved out huge basins in the landscape when the floods came these depressions rapidly filled up with water every natural lake here in Indiana Illinois Wisconsin were all created by glaciers the biggest ice scoured basins became what we now call the Great Lakes these water-filled craters in the North American landscape are nearly 5 1 12,000 cubic miles in size the water they hold could drown the whole of New York state to a depth of more than 600 ft but even that is just a tiny fraction of the total flood Unleashed as the retreating ice poured out nearly 39,000 cubic miles of water that's over 100 times as much water as is found today in every single River on Earth the flood rushed down the Niagara escarment at the rate of 42 million gallons a minute 1 and2 olympic sized swimming pools every second and that cut a Gorge 7 m long and 180 ft deep through solid rock the Ice Age had created one of the modern wonders of the world Niagara Falls the investigator's next challenge was figuring out why the ice ADV Advanced and retreated so often it wasn't until the mid 1960s that the first real Clues were discovered the US military was building bases in some of the Earth's most remote locations this is an ideal Arctic laboratory permanently Frozen under a polar ice cap which covers all but a few coastal areas of the island geologists realize that the cores of ice being extracted by Hollow drills held a unique historical record those cores and many others extracted since are housed in a laboratory in Denver Colorado we're in the Fort Knox of paleo climate what you see in these tubes is gold in terms of what we know about climate and what we've learned about climate over the the last 50 years these tubes contain 3ft long plugs of ice each dug out from layer after layer of compacted snow but it is what is trapped inside the ice that most fascinates the scientists as each Year's snow falls onto the last it builds up in loose packed layers that trap air between the snowflakes ice cores are the only archive we have really good archive we have of past atmosphere in an ice core you can see Tiny Bubbles and those bubbles are air unadulterated air from as much as 100,000 to a million years ago the deeper the bubble the older the air it contains not only a temperature signal but it contains uh dust signals that tell us about atmospheric circulation it contains a record of the atmosphere uh and specifically the greenhouse gases each ice layer corresponds with the precise time in Earth's history when its snow first fell so by analyzing the bubbles from any one layer scientists can figure out what Earth's atmosphere was like at any point in the past imagine you're writing a book and every year you add a page to that book and that page Stacks up and stacks up and stacks up the climate scientists come along later and read that page by Page by page as we go down through an ice sheet reading this Frozen record of Earth's climate has revealed that the growth and Retreat of America's ice followed a distinct pattern over the last million years or so we see a fairly regular pacing of major major glaciations roughly one every 100,000 years some theories suggest those colder spells coincide with variations in Earth's orbit around the Sun but that's not the only thing the ice cores revealed the cores that white has been studying suggest that the longer the Ice Age went on the worse it became somewhere around 400,000 years ago we went from a period that had lesser glaciations if you will to ones that were very very big so far the geology detectives have uncovered evidence of how America's ever worsening Ice Age created some of the continent's most significant features scratched rocks show how the glaciers ground their way across North America and Ice cores record a 100,000 years cycle of freeze and thaw and temperatures That Grew ever colder as the Ice Age continued but new Clues suggest that the awesome impact of America's Ice Age didn't stop there the investigation next explores how ice distorted the shape of the earth and transformed the coastal outline of the entire North American [Music] continent 2 million years ago the average annual temperature fell dramatically moving glaciers spread sheets of solid ice as far south as Illinois investigators set out to discover how thick those ice sheets were and what the weight of all that ice did to North [Music] America their first clue came in New York state on bare mountains no one knows for sure how thick the ice sheet was that came from the Northwest but right now we're standing on the top of bare Mountain about 1280 ft above sea level what we're looking at here are a series of chatter marks these are features of glacial erosion they're produced by large blocks of solid rock embedded in the base of a very thick Glacier those Boulders impinged on this Bedrock surface plucking pieces of rock off as the glacial ice moved over bare Mountain Charles magarian Mountaintop discovery shows how thick the advancing ice must have been the glacial ice sheet could care less about this large mountain there's no question that the glacial ice sheet traveled over bare Mountain as if it weren't even there and most people think that this glacial ice sheet was about a mile thick or more the marks are clear evidence that the New York ice Chic must have towered about four times higher than the EMP Empire State Building figures like this have enabled magarian to estimate the total amount of ice that buried North America it's a staggering 17 million cubic miles of ice imagine this block of ice it's uh about 6 in thick being the GU sheet that covered North America during the last glaciation you need several billion of maybe 100 billion it's it's a number almost too big to [Music] imagine this block of ice weighs 27 lb and is just half a cubic foot in size but there were 17 million cubic miles of ice covering America when scientists calculated the total weight of the ice it was an almost incomprehensibly large figure 68 8,000 trillion tons unsurprisingly such a vast weight of ice did not just affect America it distorted the shape of the planet I've got a beach ball here that has a depiction of the whole earth and every continent on it and right here is the outline of North America and during the Ice Age snow started to accumul acculate in Canada and as that ice thickened it started to flow from the centers of snow accumulation Southward into North America reaching its maximum extent right here in Illinois and when it did that this mass of ice depressed the continent Earth's solid crust sits on top of a layer that scientists call the mantle semi- Molen Rock which behaves a little like hot sticky plastic the weight of the vast plains of ice pushed down Inland areas and simultaneously made parts of the coastline bulge up from the sea but investigators have also found evidence of other ways that the ice altered the outline of America's coasts the borders with the sea that Define the continent we see today a vital clue came in downtown Miami in the unlikely setting of a municipal courthouse we're here in front of this impressive building uh built in the early 1900s because of the materials used to face its surface these stones are constructed of fossilized coral reefs and if you know what you're looking at it can actually tell you quite a bit about Florida's past and maybe its future the coral stone is made from the hard calcium carbonate skeletons of tiny sea creatures animals that only grow in very shallow water but this Courthouse Stone was quarried out of an ancient coral reef that Now lies a mile from the present day ocean and way above sea level I'm standing here about 5 or 6 feet above sea level and walking alongside this rock face which is about 6 feet tall the interesting thing about this rock face it's actually composed of fossilized corals and the fact that we're standing here today amongst these fossil corals tells us that in the past we would have been under 10 or 15 ft of water right now the coral stones have been dated to around 130,000 years ago which means the sea level around Miami must then have been been far higher than today as experts tried to figure out why the sea level was so high then new evidence emerged about Florida's coral reefs and the Mystery deepened even further divers off the coast of Miami found a coral reef now submerged 450 ft under the water these corals grew just 25 ,000 years ago and because a reef like this only forms in shallow water the scientists realize that the sea level back then must have been far lower than it is today and that means the coastline would have been in a completely different location right now we're about 2 miles offshore fort lauderale on the edge of the Gulf Stream but 20 25,000 years ago at the time of sea level low stand we would be sitting right next to a beach here we'd be looking where we see today the ocean and the highrises in the back we'd be looking towards a sandy beach in front of a gently rolling Hillside investigators studying the coral records figured out that the up and down sea levels would repeatedly have altered the entire shape of America if you look at the outline of North America the outline that I learned to draw in elementary school if we were living years ago I would draw Florida differently 25,000 years ago when sea levels were low Florida was Triple the size it is today because more land was out of the water geologists realized that the changes in sea level around the coast were directly related to the different levels of ice on land that Discovery was the key to understanding what the Ice Age had done water evaporated from the oceans and condensed in the atmosphere to form snow but in the colder times that snow built up as ice sheets on the land and with so much of the world's total water supply locked up as ice the oceans simply ran short of water and the sea levels fell when the earth is cold there's more ice on the land and sea level is lower because of that when the earth is warm there's less ice on the land and sea level's higher and that makes sense because when that ice when it melts off the land it's got to go in the ocean the story of how ice sculpted modern North America is drawing closer to the present day chatter marks in Upstate New York reveal that ice sheets grew a mile or more thick and ancient reefs are off the coast of Florida proved that water levels in the ocean changed again and again ice had shaped the continent now scientists discovered that it had also uncovered a bridge to other lands and shaped the future of [Music] mankind North America's Ice Age began 2 million years ago as the Earth moved around the Sun America's temperatures fluctuated 130,000 years ago it enjoyed a warm tropical climate then 25,000 years ago it grew colder than ever glaciers covered 23s of North America with ice up to a mile deep now now the investigation examines how these freezing temperatures altered the course of human history in North America at Paisley caves in Oregon scientists are unearthing vital clues that humans Left Behind here's your coite a beautiful specimen the evidence is copper light fossilized human excrement this site is the location of the find of the oldest human remains that have been directly dated here in the United States with DNA in them that indicates uh people from uh probably Siberia came here at least 14,300 years ago today North America is separated from Siberia by Open Water but the presence of men from Siberia on American soil is compelling evidence that around 14,000 years ago a land bridge must have linked the two continents geologists know that the amount of water locked up as ice on land meant that there was less water in the oceans more importantly for the future of the US the retreating Pacific and Arctic oceans left the seabed between America and Siberia high and dry but a doubt Still Remains The Men Who Lived in Paisley caves 14,000 years ago could conceivably have reached America by sea but that theory is diminished by the discovery of this artifact this is a tool that has been carved out of a bone belonging to a camelops more commonly called the Western [Music] camel you can see the curvature of the bone here this is the outside of the bone it would have continued on uh in quite a large Arch uh all the way around uh what they have done is to saw this piece out and then they have saw in teeth right here running all the way across the animal that died here was the ancient ancestor to the two humped camel now found in Asia few people know it evolved in the US camels have been here for about 40 million years so what has been surprising to me is the fact that people didn't know that camels were here in fact the earliest camel fossils ever found were discovered in South Dakota and predate find elsewhere in the world by millions of [Music] years the finds are clear evidence that camels evolved in America and once lived nowhere else on the planet so camels which couldn't have migrated by sea could only have crossed into Asia via a land bridge but mystery remains fossil records show that camels disappeared from North America 12,000 years ago scientists want to know why there is no doubt that the end of the last ice age we saw a substantial reduction in the number of species here in the Western Hemisphere so what causes those things uh it's possible that weather changed so dramatically so quickly that they could not adapt back in Denver in the ice core lab Jim White is examining the piece of evidence which could confirm that the Ice Age killed off the camels this is a really fascinating piece of ice and one of the most important pieces of ice that we have in the collection this is the the aha moment of climate change the evidence is an ice core a frozen time capsule recording the temperature of North America 12,000 years ago it shows that the US suddenly got even colder we've opened our book of climate and if we read the book from today going back in time that's page 12,000 and imagine if you will from this moment back in time we had a thousand years of cold it's evidence of the last gasp of the Ice Age another rapid freezing of America these abrupt climate changes can be a 10° C change in temperature in 50 years or less uh temperature changes of a degree celsius per year sustained over several years that is a 16° fah fall in temperature you're looking at going from a Miami to Montreal kind of change in climate The Big Chill occurred quickly from mild to freezing cold in less than a century but it lasted nearly 1,600 years it was a deep freeze so great that it proved too much for North America's camels mammoths and other large animals we're on a roller coaster of climate change that must have been extremely stressful for the uh plants and animals that were living during that time this final deadly Big Chill of the Ice Age ended 10,000 years ago it was the last time ice Advanced across the continent scientists investigating the legacy of the advance of America's ice sheets have discovered copper light strong evidence that glaciers caused the sea level to drop exposing a land bridge that linked Siberia to North America and this ice core which records the final deadly deep freeze of the Ice Age next scientists investigate how the end of The Big Chill marks the beginning of the warm period America enjoys today and how that may spell disaster for some of her greatest [Music] cities [Music] deep freezes over 2 million years have seen giant ice sheets rampaging across North America that ice crushed scarred and flooded the land to create some of America's most recognizable geological features the Great Lakes the mighty Mississippi and Niagara Falls were all created by the action of advancing and then retreating ice for the last 10,000 years the earth has experienced warmer and warmer temperatures and the passing of its ice has impacted the North American continent in other equally significant ways the ice changed the existing conditions on the landscape it's changed the way we live in this environment we get our drinking water from these materials our Rich agricultural soils are a part of that Legacy the most productive Farmland in the world is right here in North America from an economic standpoint alone the billions of dollars worth of productivity of Agriculture are a direct result of the ice age during its Ice Age vast areas of North America were covered by glaciers today they cover just 29,000 square miles America's dwindling ice is a precious resource each summer in Washington state alone melting glaciers provide 470 billion gallons of drinking water but it comes at a price the melting ice has pushed up sea levels by a foot each century and that rate is increasing and the scientists who study life in the oceans are seeing firsthand the impact it is having the coral animal itself builds a city very much like we humans do the coral had to move as sea level changed as sea level went down it had to follow that sea level down a sea level came up it had to follow that sea level up the question we have to ask ourselves as humans as sea level changes will our cities have to adapt just like the coral reef currently about 10% of the world's total land surface approximately 6 million square miles is covered by ice [Music] sheets but this ice is melting fast if present warming Trends continue all the glaciers in Montana's Glacier National Park will be gone by 2030 today North America's longest glacier is the bearing Glacier in Alaska it is 130 Mi long long and 10 m wide with solid ice up to half a mile deep but over the past 20 years that ice has become thinner as much as 600 ft thinner at the point where the glacier reaches the sea so much ice is Now Melting that every year it pours out at least 7 cubic miles of flood water twice as much water as there is in the entire length of the Colorado River over the same time Arctic sea ice has shrunk by 250 million Acres an area the size of Texas and New Mexico combined if Earth's ice continues to melt at this rate it will once again redraw the map of America's coastline this is what Florida looked like in 1995 here is what it could look like in a 100 years a loss of more than 4 million Acres where 1 and2 million people lived in 2010 and at the ocean's present rate of rise this is the coast of Florida as it might look at the end of The Next Century in the year 2200 this is Miami or what's left of it by then the city's Ocean Drive might be a drive under the ocean a return to the Sea levels of 130,000 years ago the geologists investigating America's Ice Age have found evidence that the power of ice has been crucial in helping to create modern North America bugs in Sea mud acted as Tiny thermometers recording the start of America's Ice Age morine Hills proved that moving glaciers flowed far enough to cover 2/3 of the continent Under Ice crescent-shaped marks on a Mountaintop in Upstate New York showed that the ice sheets grew to be more than a mile thick and ancient Coral beliefs were evidence that sea levels repeatedly changed throughout America's 2 million yearlong Ice Age the investigation has uncovered the full picture of how ice sculpted the geology of the US but that process is not yet finished as North America's ice melts back it uncovers a landscape that's been buried for thousands some sometimes millions of years living proof that the Earth is never at rest Earth a unique Planet restless and dynamic continents shift and Clash volcanoes erupt glaciers grow and recede Titanic forces that are constantly at work leaving a trail of geological Mysteries behind this episode explores The Incredible Journey of one of the most indestructible and valuable metals on the planet gold created in outer space an immense explosion blasted minute particles of gold at 70 million mph into the rocks that form our planet how tiny pieces of scattered gold accumulate to form massive deposits is one of Earth's great Mysteries to find the answer geological detectives sift through ancient riverbeds hunting for Hidden Treasures above and below ground and investigating alien natural wonders finding clues that will ultimately reveal how the Earth was made gold has mesmerized man for thousands of years the oldest known precious metal it plays a powerful role in almost every culture on Earth since humans have been on this planet gold has been prized it is such a unique mineral it is beautiful you can take an ounce of gold and stretch stretch it in a thin string and it'll go for 35 miles but the key to Gold's enduring value is its inactivity it won't bind with anything else except itself gold doesn't get used up it gets recycled the ring you're wearing may be the exact same gold that was in some of the gold of pharaohs wore centuries ago with all these properties it's no wonder gold has been treasured by man down through history man has mined gold for thousands of years but found only 160,000 tons worldwide enough to fit comfortably inside a four bed [Music] house physicists discovered that this ultimate metal was created in outer space long before planet earth existed over 5 billion years ago gold and other heavy metal atoms formed in the Maelstrom of a supernova a giant dying Star as it exploded shock waves blasted minute gold particles Across the Universe at 70 million mph scattering them far and wide throughout the early solar system as this cloud of rubble compacted together the gold became trapped inside the rocks of the newly forming planet Earth widely dispersed and inactive to this day most of the Earth's gold remains as Tiny isolated particles in the Rocks it's ironic but gold is around us everywhere it's in the soil in our backyards it's in these rocks here in the riverbeds but the problem is it's in very small amounts in these rocks the gold may be at one pot per billion that's like finding just a grain of sand in an Olympic siiz swimming pool unusually large stashes of gold are concentrated in a handful of very special places around the world the largest in Southern Australia China South Africa Peru and the western United States it is the geologist job to find out where and why the Earth Earth accumulates gold in large enough quantities to mine the first pioneers of gold geology were not scientists but gold hungry Prospectors who scrutinized the Rocks their story began over50 Years Ago by accident in 1848 in the small Californian town of Coloma along the American River James Marshall was digging a trench for a water wheel to power his lumber mill when he made an extraordinary Discovery he was digging it down during the day and then using water at night to flush out the sand and gravel and he looked and there on the Bedrock were a couple of gold nuggets rumors of California's River Gold spread like wildfire by 1849 over 990,000 people from around the world descended on the state nicknamed the 49ers these early investig ators searched the streams in a bid to find their Fortune their first challenge was to figure out where gold accumulates in the river and they quickly discovered that gold wasn't just strewn anywhere along its course a clue to where the gold would be concentrated is black sand in areas like this you take a sample and pan it out the 49ers soon learned if they found heavy black sand in their pan they were on to a winner the process of panning is a simple one you're really trying to separate light materials from heavy materials in this sluggish water the heavy particles sink to the bottom of the pan and you repeat the process of washing away light materials and then concentrating the Heavies on the bottom until you get down to just the black sand and hopefully some nice gold even a small nugget like that in the same way rivers and streams separate the heavy particles from the light the gold and black sand are flushed Downstream but as they hit the sluggish water on the inner bends they drop out of the [Music] flow and it's here in the sandbanks on on the inside bends of the river that the 49ers discovered an absolute fortune in total over 20 million ounces of river gold were discovered in the waterways of California but when they investigated the valley sides above the river the 49ers discovered an even bigger stash of gold and they wondered what was the deal with these gold deposits that were up and away from the water they took a close look at them and they could see that these Boulders were round and smooth these rounded Boulders are identical to those found in the rivers nearby and the reason is because it's an ancient riverbed it's been left high and dry by the flow of the river the River cuts downward and leaves these deposits behind the miners continued to explore and they found some just above the river like this but they found others tens and even hundreds even a thousand ft above the modern stream using powerful water jets the 49ers blasted and flushed out a further 50 million ounces of ancient river gold from California's Hills which still bear the scars over 150 years later similar river gold deposits have formed all over the world including the greatest Treasure Trove ever found with Waters Rand in South Africa its Discovery in 1886 caused another massive gold rush but this River Gold is not found on the surface miners must descend over 2 miles down the deepest mine shaft on [Music] Earth half the gold on this planet has been produced from that one group of deposits most geologists believe that these unique deposits formed from ancient river systems concentrating these in Old River gravels over millions of years thousands of ancient Rivers carrying gold spilled into a huge Lake dumping a massive gold deposit this ancient lake bed is now buried miles Underground to date wiwat Rand has produced over 1.4 billion ounces of gold worth over 1 and5 trillion dollar and geologists believe the same value of gold Still Remains untouched in the search for California's River Gold 49ers found heavy black sand a sign that gold is deposited on the inside Bend of a river and gold buried beneath rounded Boulders in the valley walls proof that Rivers have been depositing gold for millions of years the 49ers suspected that Rivers were carrying gold down from a source somewhere in the mountain the motherload but the quest to understand where this motherload gold originated would take geologists deep inside the earth and face to face with some of the most destructive powers on the planet in the 19th century the 49ers plucked 70 million ounces of river gold from California's streams and ancient riverbeds valued at more than $80 billion but this easy gold didn't last the race was on to find the source of the river gold the motherload and they set off into the mountains to investigate and this is what the old-timers were really looking for a big wide vein of quartz filled with gold it runs literally for Miles through the countryside they were able to mine millions of ounces of gold from sources just like this with the discovery of motherload gold prospecting changed from a solo quest to Big Business hundreds of Mines sprung up all over California employing thousands of men discovering what geological Force had concentrated gold in California's mountains was a puzzle that would bamboozle scientists for decades in 1853 the alany mine opened in Sierra County California today it's over 3,300 ft deep with over 40 miles of tunnels all leading to one special slice of rock in the mountain here I am in the middle of the motherload vein it must be about 40 ft thick and it goes down half a mile into the Earth this is the gold bearing quartz bin that the miners were seeking quartz forms from a liquid and as it solidifies it somehow traps lumps of gold inside it it is loaded with gold if we break these clutz veins open though we can see perhaps small amounts of gold within the quartz this is just an amazing piece of quartz you can see all the free gold in it it's just bright and glistens there are actually Clues to how the gold got here within the quarts that was deposited with the gold trapped inside the quartz are tiny bubbles of fluid they are minute remnants of a stream of water and minerals that once gushed up this vein analysis of these fluid bubbles has revealed the extreme conditions that created the gold seam that gold was deposited at 600° Fahrenheit it was a very very hot fluid that brought the gold and the quartz to this location and deposited the vein but it was a mystery what was the driving force creating all this hot fluid which carried the gold in an Old Quarry nearby a clue the gold bearing quartz vein here stained Brown is flanked by strange beds of altered Rock when the old saw rocks like this they would get excited they knew they were getting close to the source of the gold they would see these rocks had changed their color and then they would get to the big motherload quartz vein the sauce of most of the gold or this quartz vein is sandwiched between these altered rocks and looking at these altered rocks you see they're all deformed they're up on end they're sheared up they're broken they're folded these veins run for hundreds of miles in a north south Direction similar sandwiches of gold quartz and broken rock are found along the entire length of California and strangely they all run parallel to the coast whatever immense Force shattered these rocks must also have created the hot fluid which carried and concentrated the gold but what was it geologists finally solved the mystery in the 1950s when the Revolutionary theory of plate tectonics shed light upon how California and its mountains were made they discovered that beneath the Pacific Ocean a giant plate of the Earth's crust moved eastwards it plowed into the American continent crumpling huge slabs of the seafloor as it went if this big rock is ancient North America over the last 300 million years we had a spreading ocean floor pushed the ocean and sediments on top of the ocean against North America and stack these pieces of ocean floor and sediments on ocean floor up on end against Western North America California was pushed above the waves a mountainous mass of crushed crumpled and upended rocks separated by huge cracks running deep into the crust creating a landscape compiled of giant slabs stacked parallel to the coast this immense mountain building process also had the power to create a piping hot fluid buried rocks were squashed under unbearable pressure they superheated and a 600° fluid was squeezed from them like water running in a river this piping hot fluid had the ability to concentrate the scattered gold as it washed through the rock it leached out minute particles of gold creating a mineral Rich soup it poured into the giant cracks which pipelined it to the surface as the fluid cooled the gold coagulated and the quartz crystallized forming a solid gold-bearing quartz vein in total 35 million ounces of this mountain gold were blasted out of California one of the most profitable gold mining areas of its time wherever you have oceanic plates colliding with the edge of a continent you're always going to create fluid you're always going to move those Trace amounts of gold and that will get focused into major faults to form large load gold deposits that part of the mountain building process similar gold bearing quartz veins lie beneath the coastal mountains all around the Pacific Rim where the ocean floor has crumbled under gigantic Earth forces scientists investigating how California's Mountain gold formed have found ancient fluid bubbles proof that a hot liquid deposited the quartz and gold parallel beds of broken altered rock evidence that the gold Rich fluid was squeezed from rocks as mountains formed by the 1880s only 30 years after the first gold strike California's Mountain gold became increasingly difficult to find by then gold hunters in neighboring Nevada had stumbled upon an entirely different type of gold deposit but it was the sort of deposit that could drive men to murder in the 19th century 49ers found 70 million ounces of river gold then they began to rans sack the motherload blasting out over 35 million ounces of Mountain gold squeezed from the Rocks as California formed for many years scientists believed that only the Colossal forces that created mountains had the power to concentrate gold scattered throughout the Rocks but gold strikes made in neighboring Nevada were to shatter this Theory massive gold veins were found in the sagebrush Hills of the desert a tidal wave of gold Hunters left California heading east the almost Uncharted desolate state state of Nevada began to light up with life as gold strikes were made across the high desert this was the gunslinging wild west and the rough mining town of bodh had one of the toughest reputations it's hard to imagine more than 8,500 people up along this stretch here lawlessness lots of fights breaking out lots of saloons opium d and broths it was said that a man a day was killed in bod and some historians believe the fickle geology of these gold deposits may have played a part in this murder rate here the veins were much more segmented and broken up so while one Miner might be mining along on the vein another minor might not be which would lead to animosity and tension an occasional fight geologists realized that unlike California's gold scenes which ran parallel to the coast Nevadas were scattered randomly across the desert the hunt was on to understand why Nevada's gold veins were so chaotic 300 mil Northeast of the cramped old mine in bodh is the Midas mine large enough to drive a truck down it's one of a handful of remaining gold quartz mines in Nevada and it's a geologists Paradise it's wonderful to have an underground mind because when you go underground you have a three-dimensional picture of the geology it really helps you get a feel for what Clues to be looking at uh that we might see on the surface that we might see better expressed underground working Minds like Midas have become geological Laboratories and are helping to unlock lock the mystery of Nevada's scattered gold [Music] veins every day the miners drill the face and pack it with explosives exposing new networks of quartz veins this is just like the old days but more high-tech they're going to drill the face out load it with explosives and blow it up 450 lb of explosives are about to blow low to reveal the gold bearing quartz [Music] vein that was great and to think it's so much safer than what the oldtimers had to go through once the dust settles it's possible to take a closer look this is quite a nice big quartz vein if I compare these quartz veins to the veins that I've seen in California they're substantially different for one if I look at these bands these dark gray bands in here these gray bands are the first sign that something very strange has happened here in a hand sample I'll see that there's lots of gray material all that gray material is silver if I look even closer closer I can see little fine flexs of yellow that's gold The Source rock that formed all of these veins was much different than the source rock that caused the California veins to form the California veins only have gold and these are loaded with silver and the clue to the identity of the source of Nevada's gold lies either side of the quartz vein unlike California these wall rocks are not crushed and have never been on the ocean floor this wall rock is of a volcanic origin very similar to like Mount St Helens so it wasn't mountain building that concentrated the gold and silver in this vein it was a volcanic process perhaps the Midas mine was once a giant volcano geologists went looking for Clues not inside the mine but directly above it everywhere above the mightest mind we see these strange outcrops they're flat on the top like a table and if I look closer I can see fine little bands and layers the outcrop is made of thin layers less than an eighth of an inch thick and there are thousands stacked on top of each other like a deck of cards You' got Browns and yellows whites and purples understanding outcrops like this will help us understand why gold is deposited at such shallow depths within the minus mine these distinctive layers rocks are not formed by a volcano but another type of volcanic process that can still be seen today in gerlock Northwest Nevada in the middle of the dry Black Rock Desert they found a mysterious Oasis and rising out of the landscape a spectacular multicolored hot spring one of over 300 in Nevada this bizarre geological Wonder began to form just 45 years [Music] ago volcanic processes beneath the Earth heat the ground water it spills out at the surface and like a boiling tea kettle dumps a layer of mineral scale the water is slowly running over the tops of these Terraces it's depositing minerals in fine little sheets kind of like a deck of cards or a book on end this rock from over there has fine laminations or layers rocks like these and Terraces like those are found right above the Midas mind which tells me that Midas was once an enormous hot spring geologists realized it was hot springs that brought the gold and silver quartz veins to the surface in Nevada Gold and Silver particles are scattered in molten rocks deep inside the Earth this hot rock released a golden silver Rich fluid as rainwater soaked into the ground it reached the scorching rocks deep in the crust and superheated to 900° F hot and buoyant the water began to rise sucking up the gold and silver soup as it went as it neared the surface the water boiled and dumped bands of silver and flex of gold in the chaotic fractured pipework of the hot spring imagine this landscape 15 million years ago volcanoes as far as the eye could see Hot Springs dotting the landscape here and [Music] there gold is forming at this moment in Hot Springs all over the world even Yellowstone has traces of gold in its water one of the world's biggest and most profitable gold m mines yanaka Northern Peru is a gold and silver deposit which man has plundered since the rule of the Inca 800 years ago high in the volcanic Andes it's a massive 535 square miles and has produced over5 billion worth of gold all of it originating beneath a bubbling hot spring scientists investigating how gold silver veins formed in Nevada have found Volcan anic wall Rock proof that the goldrich fluid came from molten rock and a multicolored layered outcrop evidence that ancient Hot Springs deposited gold in Nevada Nevada's hot spring gold deposits yielded over 40 million ounces of gold and 500 million ounces of silver but by 1920 Nevada's gold seams were increasingly uneconomical to mine the desert became littered with ghost towns it looked like America had run out of gold but in 1961 a new type of deposit was found but it couldn't be seen or touched it was invisible it would become the biggest strike in the history of America's [Music] gold America's gold was concentrated by incredible mountain building forces that formed California and Volcanic processes deep beneath Nevada's Hot Springs but as the deposits became exhausted geologists frantically searched for new stashes of gold then in 1961 geologist and gold prospector John Livermore noticed a suspicious 50m long crack in the middle of Nevada called the Carin Trend and set out to investigate John Livermore came to these following up a theory that gold deposits would be aligned directly above a deep Kraken ear's crust he come up to out crops like this and he would go ahead and want to look at them the rocks are a strange mixture of mud and quartz a mineral created in hot fluid and a good clue that gold might be deposited nearby based on his experience he knew a lot of hot fluid had come up this crack however he couldn't see any evidence of gold no quartz veins no visible gold but on a hunch he sampled this rock took it back to the assay lab to see if there was any gold in it in assay Labs rocks are crushed and blasted in a furnace to over, 1800° and as the liquid rock cools the minerals begin to separate at the end of the this process something extraordinary has happened an ordinary looking Rock actually contained a grain of gold at a concentration of about 5,000 times you would normally see in the earth doesn't look like much but this is what they mine every day livermore's hunch paid off 50 m long and 5 miles wide the Carlin trend is now one of the largest mining districts in the world this vast man-made pit is is big enough to be seen from space this is the Betsy post pit one of the world's largest gold Vines contains 45 million ounces of gold they have to mine 10 tons of rock in order to get 1 ounce out as you can see it's huge 2 mil long mile wide 2,000 ft deep because gold is so valuable the extraction of just a few thousand ounces a day pays for this extraordinary mining operation and removing the gold ore requires drastic [Music] action wow that's what 400,000 lb of explosives looks like giant diggers work 24 hours a day Excavating over 90 million tons of rock a year enough to cover Central Park in 55 ft of rubble but within this raw gold ore not a speck of gold has ever been seen with the naked eye the mystery is where's the gold you can't see it the rocks look really ordinary the clue to where this gold is hidden is an internal structure of this rock magnified 500 times the gold is still invisible but this rock is an extraordinary lattice of quartz and mud perforated with strange cavities it looks like a honeycomb like something's eaten away at it clearly some strange geologic process has concentrated and hidden the gold in the Rock scientists realized if they were going to solve the puzzle of how gold came to be hiding in in these rocks first they would have to understand where the Rocks came from a clue was found in the 19 century by cattle rancher absum Leman in the Eastern reaches of [Music] Nevada in 1885 Absalon Lan stumbled upon a hole in the ground and with rope and Lantern he lowered himself in the earth in the discovered this beautiful cave system with some of the most spectacular cave formations in the world the solid foundations of this cave are made of a messy mixture of mud and calcium carbonate shells they are the remains of tiny sea creatures evidence that Nevada was once covered by an ancient tropical sea for millions and millions of years creatures with shells composed osed of calcium carbonate began to rain down through the ocean and accumulate on the sea Flor forming this calcarius ooze later this ooze hardened into a sedimentary rock called Limestone these extraordinary structures in the cave were formed when water eroded the huge Limestone bed that sits underneath Nevada and back over at the Carlin Trend scientists noticed that the gold ore was made of a very similar type of rock they figured out that the Leman cave Limestone and Carlin Tren gold ore must once have been the same rock this is fresh Limestone this is gold ore clearly something happened to change this rock into this spongy gold bearing ore well the clue is in the chemical reactivity of this limestone if I put the loot hydrochloric acid on this Limestone note how it fizzes very reactive the acid is eating away at the Rock now if I put the acid on the spongy gold ore no reaction the fluid is soaking into the Rock like a sponge scientists concluded the reason Carlin Tren gold or did not Fizz is that it had already been attacked by an acid beneath the bed of limestone at Carlin is a gigantic vertical crack geologists now believe that a blast of hot acidic goldrich fluid was once forced upwards from deep within the Earth it streamed through the crack drenching the Limestone the acid ate into it leaving a sponge like muddy framework behind and in the cavities it dumped quartz and the most minute sprinklings of gold it's only been very recently that scientists have been able to use even more sophisticated Imaging equipment microscopy to image down to the scale of individual atoms magnified 100,000 times tiny specs of sub microscopic gold can be seen embedded in the Rock zooming in further a staggering 4 million times the gold particle is finally revealed this Fleck of gold is only 5 nanometers in diameter 1 millionth the size of a pin head and each tiny white dot is an individual gold atom these ordinary looking rocks have produced 65 million ounces of gold from a single crack in the earth known as the Carin Trend and it's made the United States the fourth largest gold producer in the world scientists investigating how Nevada's gold ore formed have found a spongelike rock structure suggesting that something ate away at the Limestone and gold ore not reacting with acid evidence that an acidic fluid had already attacked the Limestone showering it with minute particles of gold similar Carin type deposits have since been discovered yielding a further 35 million ounces of gold yet these discoveries may only be the tip of the iceberg geologists are now using state-of-the-art equipment hoping to unlock millions of ounces of American Gold trapped deep beneath the Nevada desert throughout world history over 5 billion ounces of gold have been recovered by man and almost one tenth of this has been found in California and Nevada adding up to a staggering $280 billion worth of bounty how much remains is anyone's guess there is no reason not to assume as much gold exist as has been mined in the past but geologists Prospectors explorationists have found the easy gold in the past Prospectors and geologists homed in on this easy Gold by following geological Clues Exposed on the surface but vast areas of Nevada are covered in a deep layer of mud and gravel that has been eroded from the surrounding mountains geologists believe believe hordes of gold still lie concealed beneath this layer of gravel unseen by anyone for millions of years finding all this buried gold in an area covering 110,000 square miles is no easy task but one man has the ability to see under the ground using pioneering technology I've got gold in the hills around me I've got good reason to believe there's gold beneath me in the Rocks if I could just see through this sand and gravel this little piece of equipment I believe is going to help me figure that [Music] out the Geo probe is drilling not for rocks but for groundwater 200 ft below the surface and it's this groundwater that holds the key to finding Nevada's hidden gold if there's a gold deposit concealed by the sand and gravel the groundwater will interact with it and you pick up Clues traces of metals associated with gold seep into the groundwater clues that will lead Hodges to the secret location of the gold deposit deep below the surface imagine an iron bar rusting in a bucket of water the trace metals are going to come out of that rusted iron bar going to be disseminated in the groundwater and you would be able to sample that groundwater and tell that there was an iron bar somewhere nearby just as we're going to be able to sample this groundwater and know that there's a gold deposit somewhere nearby so in a sense it's like the deposit of gold is creating a scent if Hodges can latch on to a whiff of this scent he can track it back to find the gold once the drill is deep enough Hodges pumps out the [Applause] groundwater okay I think I've got enough sample now somewhere in this bucket of Muddy Water I believe we've got some Clues this is no ordinary pickup truck it's a state-of-the-art mobile laboratory Hodges measures how many Trace metals are in the groundwater and the scent here is particularly strong and it's telling me that I've likely got a lot more uh Trace Metals arsenic animony uh Mercury uh copper Le zinc are the kinds of Trace metals that are often associated with gold deposits and looks to me like uh We've moving in the right direction in in the same way the old-timers trace the gold up into the mountains Hodges tracks the increasing concentration of Trace Metals in the groundwater it's like a little childhood game of of hide and go seek am I getting hotter or am I getting colder and that makes it a science the net is tightening around the gold deposit the scent is strongest in this 4 square mile Target Zone but it's still too large an area to begin test drilling for gold to focus in further Hodes needs to literally see inside the earth well this instrument here is the gravitometer and it has the ability to measure how dense the rocks are beneath this point just as there's a landscape here in the Horizon behind me there's a landscape in the Bedrock underneath me multiple readings from the graviton Omer create a secret treasure map of the terrain submerged beneath the surface gravel from this rock density map Hodges can pinpoint the likely location of the gold deposit he has found a suspect gash in the earth over a mile long and 250 ft below the surface it's a good sign as gold is often found deposited in deep cracks it's time to start drilling for [Music] gold the diamond studded drill probes the crack and extracts a cylinder of Bedrock this is the first in a sequence of test drills along the crack and the results are tantalizing after all this traveling around I'm finally able to see the rocks for the first time these rocks have been out of view for millions of years and to me it's it's one of the most exciting things about this line of work I get to look at these rocks before anybody else has ever seen them and I can compare them with the rocks that I've seen elsewhere in the mountains in this piece of core I've seen several different kinds of fragments of rocks uh some of them are quartz quartz we know is good for gold Hodges could be on the verge of a massive Gold Strike adding to his tally of 30 million ounces discovered so far reaching down into the Earth pulling out a sample that says there's gold in it and realizing that you've done it and in a sense it connects you with those oldtimers The Same Spirit of the old west it's exciting it's pioneering geologists like hajes who will find what's left of America's gold scientists and Prospectors investigating how gold is concentrated around the world have found gold in heavy Black Sands evidence that Rivers concentrate gold on the inside bends parallel beds of broken altered Rock proof that gold Rich fluid was squeezed from California's mountains multicolored layered outc crops show that ancient Hot Springs deposited gold quartz veins in Nevada and spongy gold ore evidence that an acid dumped minute sprinklings of gold in the Rock the Earth does not relinquish her gold treasure easily man's irresistible urge to find gold is the driving force which helped Pioneer the science of geology investigating how gold is concentrated across the world is not just a story of metal and Mining it's an epic tale that has revealed how the Earth is dynamically changing to this day and over billions of years of the planet's history living proof that the Earth is never at rest a

Channel: HISTORY

Views: 8,016,773

Keywords: history, history channel, history shows, history channel shows, the history channel, documentary history channel, history documentary, documentary, history channel full episodes, documentaries, history channel documentaries, marathon, How the Earth Was Made, How the Earth Was Made streaming, watch How the Earth Was Made online free, How the Earth Was Made full episodes, How the Earth Was Made scenes, How the Earth Was Made clips, Deadly Wastelands & America's Ice Age

Id: zCzptZIxvdA

Length: 177min 45sec (10665 seconds)

Published: Wed Oct 25 2023