Ellensburg Blue Agates

Ellensburg blue agates how can I get you interested you're here I mean you're demonstrating your interest but I think I'd like to try something to hook you even a little bit more I teach geology for a living and I love telling stories about the geologic past and to me the Ellensburg blue agates are a way to tell a particular story I love the agates just as much as you do but I also like the context of the agates and the part of the value that the agates are coming from and the story that they tell so let's try this how's your sense of direction what direction is north that's good okay good so North is that way so if this wall wasn't here and we had a beautiful view of the skyline north of the valley do you have something in mind you got a mental picture for that I do let me show you what I have in my mind we'll see if it matches with yours okay there's kind of a a low dark colored Ridge that forms the edge of our valley a low dark colored Ridge and then kind of sticking up beautifully behind that low dark Ridge the Stuart range right Mount Stewart in the Stuart range that's not a major player of today's story but we have talked about Mount Stewart earlier in this lecture series this is a series we've taken three years off but there was a lecture series not here but at Ross pace a couple blocks away and we had 12 of those lectures so there's mount Stuart stuff and other things so occasionally be referring to that and I guess there's a there's on this side of the ridge there's kind of an impressive that's the nanum canyon and up the high nanum is there's kind of a a ridge over there okay so let's just put a couple of place names on this little view of the skyline and then we'll zero in on how the blue agates fit into this story so over here on the east on the right of our skyline here's where we're we're skiing up on Mission Ridge right okay and the snow hangs on there a little longer than the rest and and up here on top we've got Table Mountain and the rest of the Wenatchee mountains and lions rock is up there and and reser Creek Road kind of switchbacks its way up you can drive on pavement right up to Table Mountain and it's very handy place with me so far between where that resore Creek Road goes up and Mount Stewart have you ever noticed there's a low notch there's a little piece of that low ridge that's missing that's the green Canyon not the green Canyon not that's so important we're going to write it out the Green Canyon knotch and that's important to us tonight the Green Canyon notch is important because right below the green canyon notch on the floor of this valley our Ellen's blue blue agates Ellensburg blue agates thousands and thousands and thousands of Ellensburg blue agates they're out there right now take some deep breaths alright this they have been out there for hundreds of thousands of years and they remain out there and they're really only in that portion of our valley below the green canyon not in a broad plain not over here east of Kedah tasks just up there in the northwestern corner of the Kittitas Valley ok now you're thinking why just here why not all over the valley and they're loose pick them up you don't have to get a jackhammer with you just go out and pick them up especially in the spring right with our frost heave generations of this stuff yes the pickin was easy a hundred years ago 75 years ago but they're still out there there's still some of you go out regular family outings why just this portion okay let me try to hook even more we haven't even started yet but let me hook you a little bit more what if I told you these blue agates were not created in our Valley they're in our Valley now but they were not formed in our valley that they were formed north of our valley and a river which is no longer there brought these Ellensburg blue agates to our valley and where did that River travel it came right through the green canyon knotch that's why we care about the green canyon knotch a superhighway of Ellensburg blue agates coming from north of the valley coming through the green canyon knotch and then dumping laying out beautifully bearing gifts this river bringing Ellensburg blue agates to that corner of our valley if i got you interested now i hope so if not that's all I got okay I'm going to start so the doors are open you're free to take off anytime great so now that I've got you interested we're wondering why here and why the river and why isn't the river there anymore and then the obvious questions why are they blue and are they really only found in this part of the world are there other places and we'll get to all that but not all with the chalkboard we'll just lay out some stuff in the chalkboard and then move on y'all comfortable feeling okay all right let's draw a cross-section dr. Robert Bentley who was a geologist at Central Washington University for much of his career loved cross-sections and his partner in crime Jack Powell also loved cross-sections and they created something like this 30 years ago that I like and so I'm reproducing it for you I borrow things if I think they're helpful and this is something that's very very helpful so we're going to do a cross-section from Mount Stewart - Hal home center and I need to concentrate for just a second because I can't do two things at the same time hang on hang on hey hey that'll work that'll work right I wish I could do can you do two things hey how about this could you raise your hand if you have an Ellensburg blue agate with you tonight 35 percent of the groom has some sort of jewelry or pockets full of Ellensburg blue agates of those of you how many collected your own found that own sample two or three I got nothing more to say than that I was just I was just killing time good thank you good interesting okay we need to do a cross-section which is a diagram that shows the underground geology between Mount Stewart and Hal home so that we can see where these blue agates are coming from so we have to learn our rudiments we have to learn our basic rock layers and figure out which layer is the smoking gun which is the geology rock layer that actually is producing these blue agates and once we do that then the other job is to figure out how those agates got into our valley because here we are over here this is the Kittitas Valley filled with not only blue agates but many many other river rocks right you dig a foundation for a new home and there's a bunch of loose junk that you dig out a bunch of baked potatoes rocks right I mean there's thousands of vertical feet of that stuff filling our valley that's the Ellensburg formation less than 12 million years old roughly great making up this is Table Mountain people Mountain that Ridge that low dark-colored Ridge just north of Ellensburg used to be a lot more forested than it is now that was last fall we survived that those trees will be back but that's what we're talking about here what's the kind of rock and table mountain do you know it is basalt basalt a lava flow rock that is roughly a whole series of basalt lava flows if you must know between roughly 17 and 12 million years ago the famous Columbia River basalts abalos which many of you heard of some maybe not that's part of our story as well and by the way our low dark ridge that is a significant place in all of Washington geology because those very famous floods of basalt lava the Columbia River basalts which flooded much of the state of Washington multiple times during this timeframe eventually thinned and ran out of material and they thinned and ran out of material just north of Ellensburg right here so you go to Lyons Rock you go to Lookout Mountain you go to all these places on that low dark ridge and that is the boundary between all of south eastern Washington flooded by lots of basalt lava and you take one step off of Table Mountain heading towards Stewart and you're out of the basalt you're out of the Columbia River basalts and into all these layers which are significantly older Ellensburg blue agates top so that ridge is important for a bunch of reasons one its a major boundary between flooded by Columbia River basalts and not okay great what kind of rock see Mount Stewart oh yeah we have yes let's let's do this granite in quotation marks granite in quotation marks which is 93 million years old to the average person off the street and clearly that's not you because I heard a bunch of different answers that are more technical granite is the term for this salt-and-pepper looking rock that forms underground magma cooling slowly but some of you know that there's too much black mineral content in the Mount Stewart Rock to actually technically call it a granite it actually does have a little bit more mafic content so it's closer to a grano dye writer in some cases even a diary who cares let's call it a granite great in contact with our granite is 150 million year old green rock some of you know it that's right sir pent tonight I know in the back of the room it's hard to see that sorry so serpent tonight is a metamorphic rock it's originally a basalt that has been exposed to lots of temperature and pressure and we've created a waxy green look a tough look actually looks like serpent skin let me star both of these star indicates those are two rock units that are exotic they are foreign to North America that's a whole nother lecture but the granite of Mount Stewart and the serpent tonight was made elsewhere was not made here in Washington it's here in Washington now but it was made out on the water presumably out in the Pacific Basin somewhere and brought to us and brought in to make our foundation but again we can't do too much here in one night those are the only two starred guys we've got now we're getting to the rest of the stuff and we still need our smoking gun oh I need one more unit here hang on okay good jump to 50 so these two guys are joined together they come in perhaps as one unit than they are here making up the foundation the rest of these layers were going to make I want to warn you rock layers in general are made horizontally that's a general law in geology rock layers are generally made flat originally like in the Grand Canyon so if the layers are tipped or contorted they were flat originally and then something happened to them to contort them so I'm drawing these guys like they are created this way I don't mean to imply that I'm just trying to save some time if I had more time we'd make all these layers flat and then we would tip them at the end okay but that's our little secret we know that this is after the tipping great sandstone shale drive over Blewett pass next time you drive over a blue pass on us 97 light-colored rocks maybe you just think they're Granite's that kind of look like Mount Stewart they're not they are sandstones and shales from the swauk formation 50 million years old this is good old-fashioned nor a Washington now this is a Washington before the Cascade volcanoes this is a Washington when we had very sluggish drainage from the northeast of the Southwest I'll show you a map in a little bit but we have broad lakes and sluggish streams with a very different climate by the way you know that there's lots of plant fossils in the upper county lots of leaf fossils that are deciduous and even big huge palm fronds and things like a Florida like climate that's what we should visualize here we still haven't made the Ellensburg blue agates yet we're going to do that right now there is a layer of lava sitting right on top of the swauk formation sandstones and shales again originally flat and now has been tipped what kind of lava you say lavas not good enough for us it is basalt but we can't lump it with the Columbia River basalts because the age is wrong and there's other important differences we will see momentarily 47 million years old a few basalt lava flows not just one but in the grand scheme of things let's just talk about it as one okay the Tiano a basalt there I said it that's the host that's the source for the Ellensburg blue agates where you go hunting for blues many of us go here but that's not where they were created they were created in the pours in the cavities in the gas bubbles in the fists I cavities large bugs in this Tianna way basalt 47 million years ago more on that in a second it's important to note I think that anybody want to guess what this might be how it looks like false they're not let me make them Moore's wavy this is unfair to ask again yeah yeah these are feeder dykes these are cracks that formed in the crust Hawaiian like fluid lava coming up the cracks and feeding a basalt lava flow sequence on the surface does that sound familiar to you some of you know about the Columbia River basalts and we've got the same thing feeder dikes dikes that feed the love is at the surface from a serious depth uncontaminated Hawaiian like lava coming all the way to the surface and flooding the landscape so we've got feeder dikes for these Columbia River basalts and we have feeder dikes for this tno a basalt what's the important distinction here it is the Tiano a basalt is local the feeder dikes are here the feeder dikes that fed the Columbia River basalts you may know are not in our county they're not even in Central Washington you've got to go to southeastern Washington North Eastern Oregon in some cases defeat our dikes are in Idaho or as far south as Northern Nevada to feed Columbia River basalts lows flooding the landscape so it's important to note that we have our own little miniature Columbia River basalts scene complete with feeder dikes and if you've never heard of this before again next time you drive blew it I don't know maybe tonight if you're from Wenatchee right and you just swing the head of the head beams over to the rock don't do that headlamp out right it's not all swauk sandstone and shale as you cross over blew it if you really paying attention you will see vertical walls of brown in the outcrops those vertical walls of brown are the feeder dykes that fed once upon a time the Tiana way basalt that was in the area and that basalt has been removed away that's kind of a difficult concept to visualize my point is this is a local scene I tried to learn as I was preparing for this lecture what was significant about this region forty seven million years ago to create those tensional cracks and to have that basalt event since it is the host of our blue agates I didn't come up with much so if somebody figured that out I haven't I haven't found their paper yet to me that's one of the mysteries of our story tonight why we had this Tiano a basalt event and then of course why it was so conducive to Ellensburg Bleu hosting let's finish our story and then we'll come back to the blue agates okay I'm sweating bullets up here I don't know how you're feeling 43 shale not just shale but beautiful layers of coal seams of coal you know what I'm talking about this is the Roselyn formation this is the coal that has been mined for generations in the upper County so we've completed our cross section to exotic rocks that were made elsewhere a sluggish watery scene creating leafy vegetables leafy plant materials that were falling at the bottom of that Lake being preserved as plant fossils the star of our show tonight the Tiana way basalt flooding the local landscape go back to Lakes boggy scenes to create the vegetation matter that we need for that coal then bring in long distant absolutely incredible basalts flooding the landscape and then then we can tip everybody again I haven't done this but we can do this this this and this all horizontally and then we're going to tip in the last 10 million years to actually form our valley so it may be news to you that the actual of our Valley that Ridge as a ridge has only existed in the last ten million years only in the grand scheme of our story here okay I know you might want to ask a few questions since there's so much so many of you we're going to do a little bit of that at the end if you don't mind so I'm just going to power through it a little bit more on the chalkboard then we've got those colorful stories I guess and we'll switch to the audio-visual stuff and add more to this this is just cartoon time great let's do this I'm not even gonna race this let's do this the Ellensburg blue agates are forming in the Tiano a basalt but please note the Ellensburg blue agates are not forming forty-seven million years ago this is an important distinction the tiene huevos salt is 47 million years lava coming up the fissures feeding the system we're making basalt lava but it's impossible to have quartz form in a cooling basalt lava flow quartz which is the composition of Ellensburg blue agates the mineral quartz does not go with basalt there are opposite ends of a grand scheme of how we put these rocks together so the quartz is secondary the Ellensburg blue agates are going to form long after this Tiano a basalt is created with me so let's enlarge a big chunk of the Tiano a basalt let's just magnify a big piece of it and think of it like a big sponge piano a basalt for reasons that I do not understand happy to admit that not happy to admit that I'm inventing it I mean there are there are open places in the Columbia River basalts lows and there are typically little gas bubbles you've seen them you've been out in the Hills you've seen basalt that looks like Swiss cheese it's got little BB sized holes right well those exist in the tiene way basalt and Ellensburg blue agates are going to be formed in those little vesicles they're going to fill those little holes but it's more than just the little holes you've seen Ellensburg blue aggregates at least in picture form haven't you the baguettes are the size of the holes the size of the agates are the size of the original holes that are in the lava so I'm a little head of myself let me try to lay it out if you haven't heard this before the general idea is long after we cool and solidify and form the Tiano a basalt we're going to get water some think hot water most think hot water hot fluids passing through the Tianna whip us up some think cold water I don't know why the point is water carrying dissolved mineral content are going to move through these holes and they're going to the water is going to deposit they're going to precipitate quartz around the walls of the cavity if it's a fist-sized hole we're not going to fill the whole cavity in one spot we're just going to make one we're going to paint the wall with some quartz it's like wallpaper and water coming through water coming through water coming through so in some cases we have Ellensburg blues that are banded because we are painting the walls of these cavities and the room is getting smaller and smaller and smaller as we lay more and more layers of quartz around the outside now talking about blue yet just talking about forming quartz in these open places in the Tianna webos own kind of weird right I mean you're out hunting for blues and you're looking for things to pick up the concept is kind of the opposite the thing you're picking up is the only thing that was cavity originally but you're picking up these jaw breakers that actually have concentric rings and the jaw breakers formed in these holes so let's go ahead and especially the smaller guys let's fill these holes completely completely with Ellensburg blue agate and in some of the others may we won't do the job maybe we'll only fill half of the cavity with agate material we're not done though right we've got to yawn away basalt and we've got some of the holes filled with agate material what do we need to do we need to get those agates out of there we've got to free them they're in prison and the way that what we have to do now is you rode the tian away basalt we need somebody i don't know like a river start working start taking material away and getting the material to the Kittitas Valley with the important distinction that the surrounding basalt is going to be softer is softer easier to erode then the agate that have filled the holes the hardness of these Ellensburg blue agates is even slightly a touch harder than the average quartz so this is resistive material that we are filling our cavities with and if we're starting to erode the Tiano a basalt we're taking the basalt away the country rock and we are breaking out these beautiful formations that have been filled inside of these cavities okay we're going to solve the other mystery and then we're done with the chalkboard perfect how are we going to get the Tianna way basalt material into this valley I thought I said at the open that a river is going to take material from here and get it into the valley that doesn't look possible given the present situation by the way red top have you been up to collect stuff at red top that's right here the top of this Ridge red top is right at - yeah no way basalt country here is the answer and it's one of the neatest things I have for you tonight especially if you have not heard this before I'm going to erase our sponge and I'm going to ask the question one more time and then I'm going to answer it how is it possible with this picture to have a river take stuff from the Tiano a basalt and have it go downhill and then uphill and then downhill into the Kittitas Valley water doesn't flow uphill that doesn't seem possible you got the answer ooh not the answer I was looking for thanks for the participation there is a little bit of glacial stuff in this story but not in this picture here here's the answer here's how we can solve the problem remember the green canyon gap the green canyon knotch and a river flowing from north of the valley into the valley bringing Ellensburg blue agates in our mind the only way this is possible is to have a larger Ridge once upon a time north of Table Mountain there was a lot more to yellow a basalt north of Table Mountain that was topographically higher and that's our time long ago when we had our Ellensburg blue agate superhighway delivering material to our Valley coming down the ridge and working into the valley and then through time like most things in nature if you have enough time and you have enough erosion you're especially going to erode this shale away the shale is much softer than the tiene way basalt and so it's no accident that the Roselyn shale area is lower than the surrounding red top and the rest of tiene way basalt and so here's the kicker the blue agates are no longer coming into our valley they've been cut off because we have cut to low with the Roselyn formation so that now first Creek some of you know it first Creek is taking Ellensburg blue agates to the west and into the swauk River and then into the Yakima River taking an end run and not coming directly into the Kittitas Valley anymore I got the thing I lost a couple of you there so I'm going to say that one more time and then we're done with the chalk board ready 30 seconds we used to have a major delivery system of Ellensburg blue agates and other loose rocks to the northwestern part of the Kittitas Valley the reason for that we had a ridge that was much higher originally we had a river system coming downhill crossing the Table Mountain area and dumping material into the Kittitas Valley but that high ridge has been reduced to the point where it is there's a lower spot between Table Mountain and red top and therefore we have stream capture and first Creek taking material a different way that's not a buzzkill there's still blue agates to enjoy there's just not any more common into the valley this way but we'll talk about other things as well I've sprinkled some beautiful photos of Ellensburg blue agates into this but we're going to add to the geology that we've been working on so far tonight I hope that you picked up a few new ideas from some of those concepts on the chalkboard we're going to get into the beauty of course and there's not much to teach it's just appreciation for natural beauty created here locally in the Kittitas Valley just north of the Kittitas Valley here's our banding here's our cavity being filled like a jawbreaker concentric rings okay you are here and the Stewart range is up high and here is our low dark colored Ridge if you were having a hard time visualizing it before there it is in living color for you here's a rich photo showing the same beautiful Ridge mounts to eart to the north being much older and telling a different geologic story knotch not CH this is from up by my house on Craig's Hill this is heading out there yesterday morning and taking a couple of photos this is our Green Canyon knotch that was the superhighway from a ridge that used to be higher and our blue agates are coming one by one through that gap into the Kittitas Valley most of you know that the good prime blue agate hunting is private there are a couple of public places to try we can talk about that before we quit so here's looking at a map you are here we are preoccupied now with the northwestern corner of the valley that we call Kittitas can you see our knotch and can you see our broad area here material coming through the knotch from the north another shot on Google Earth same idea we're tucked up in the northwestern corner now if you're a really prime hunter you know there's a few blues they're a little bit further west let's talk about that right now let's get on Interstate 90 and go out to Thorpe and a little bit beyond Thorpe and some of you know a little bit of the geology that's out there let's review it or introduce it for people who may not know that's a landmark two miles west of that landmark is an important geology location are there blues in this ridge which is two miles west this is right where the tandem is coming out into the valley I don't know if you want to spend time hunting up there those are Marines glacial moraines rocks being brought down from the upper Yakima drainage it's possible to have some blue agates there but that's not prime hunting material we'll talk about why in a second here's to help you see that Glacial signature two miles west of Thorpe where are we specifically we're at milepost 97 on the westbound side the drivers are climbing the ridge and the ridge is significant because glaciers once upon a time in fact six hundred thousand years ago flowed down from Snoqualmie Pass basically right down Interstate 90 passed east and pass Cle Elum passed Indian John rest area and got to this point right here got to this point right here here's our notch here's our blue agates we're in the neighborhood of this glacial advance and we're going to see that the Tianna way basalt actually does continue up through the upper County so it's not out of the question to have blue agates being transported by glacial ice like some of you were chiming in with but my spin on the story tonight is this is the major story our Lost River system coming from the North Moore with the idea the ice is coming down and leaving a ridge of glacial rocks one more little clip from this thing called central rocks which is a geology program locally ah and then something different not at the skyline but that blonde linear Ridge that's in the low country do you see it that's the moraine that's the terminal moraine of this glacier and it is a perfect marker for where the edge of the ice used to be so it's important to know that this looks like Ellensburg Blue hunting ground but not maybe a prime location but here's that moraine I don't know if you've ever noticed it before but when that freeway splits to three lanes and climbs on the way to Seattle that is a beautiful marker for the end of the ice let's get off of the Glacial stuff now good so Jack Powell a geologist long time here in the valley says we got to go back in time to look at our layers and Jack has it horizontally which we want right the original layers are horizontal before we tip them so look at this it's Table Mountain for a reason those basalt layers there the Columbia results are almost perfectly flat but they do have a regional dip to eventually go beneath hell homes and crop out again to the north at Menashe - so here in living color's what we were trying to draw on the chalkboard including our feeder dikes coming up and feeding the Tiana Webb assault the source of the Ellensburg blue agate now that you know the role players here let's look at some familiar landscapes and add the geology there's our 93 million year granite exotic to North America here's our serpent tonight that weathers to an orange but in fresh color looks green exotic to North America in fact this is deep ocean rock that was thrust up on to the edge of North America long ago yeah Sam stone right before we formed the the tiene way basalt there's our swauk formation the primary rock and the Tatum and up on Blewett this is a beautiful map from John Figge he put this whole geology textbook online by the way for free for you to enjoy this is basically a map of Washington 50 million years ago our swauk formation our sand stones that have these beautiful plant fossils in them are right here in central washington notice that the coast of Washington was very different 50 million years ago than it is today here's ocean shores today out here so a much different state of Washington 50 million years ago before the cob the cascade volcanoes here's the look of these beautiful leafy humid plants from swauk time so that's gotten us to here right before our feet our dikes and right before our tea anyway basalt story now if you're a hiker or a cross-country ski or alpine person in general south of Mount Stewart you can be on the lookout for our feeder dikes they're dark brown cutting through typically light-colored rock and again the dark brown are these feeder dikes these cracks that are filled with lava coming to the surface here's more either Mount Stewart granite or swauk formation that's probably more granite but again the point is here's our squirts of Hawaiian like lava coming to this surface and feeding the host rock of the Ellensburg blue agates 47 million basalt perhaps that's the 93 million year old granite and a very sharp contact between the two okay now we're at now we're in business now we're cooking with gas we've got our blue agates forming in the cavities of the tno a basalt so big small medium different shades of blue take them down to your favorite jeweler and get them worked on a third of the group has them on display they're holding their going to clutch it very tightly on the way out to make sure no one pulls a fast move on them we had a guy at our department at Central who was just here for a few years he's from New Zealand you'll hear his voice in a second and he went back to New Zealand for personal reasons but when he was here he devoted his research to the Ellensburg blue agates and it's unfortunate he didn't stay longer because he would have continued with his research on the blue agate I did a fair amount of x-ray diffraction analyses ok XRD yes and what does that mean exactly this is where you take a sample and you irradiate it with x-rays much like turning on a light saying in the studio here and having it bounce off the surface of this table so the table would be the mineral and the x-rays would be the light source and then you collect which about what the x-rays which bounce off and you can analyze this to figure out what minerals are present in the sample Oh terrific well firstly it turns out to be fairly complicated to figure out what causes color in a mineral or in rock and you can't just say iron different levels of iron nature's paintbrush is taking no you can't just say that what might be true for one mineral from one location may not be true for another sure and the story around town that people keep saying is that the allensburg blues are blue because of titanium or cobalt or something like this and that's turns out not to be the case okay it's a little more complicated so I've been looking at the allensburg blues and and doing everything you possibly do to study these things so chemical analyses structural analyses and mineralogical analysis and it turns out at least I think at the moment yes that the allensburg Blues are blue by a mechanism which is similar to why the sky is blue okay so you have light which enters in for the sky it's entering in from the outside into the atmosphere and then it hits small molecules of nitrogen or oxygen and scatters and that's what's happening for the Ellensburg Blues is very small particles in there smaller than the wavelength of light and when the light comes and hits them and scatters and the scattered color is blue those little particles that he discovered were little BB shapes little spheres at the tiniest tiniest levels that he his conclusion was light was scattering as the wavelength of light was in dealing with those super tiny little bee bees again it was kind of work that got started then he took off and so we'll hopefully have somebody else to continue that work it might be Bob who knows Bob works on the grounds that Central he comes in and shows me all sorts of great stuff that he's found he loves the local geology and I dragged him outside one day it had took some photos of some of his prized blue agates that he has found through the years poor quality photo but you get the idea that yes we can visualize the little gas bubbles being filled by secondary quartz that ultimately will have our blue color but it's more likely to have our larger cavities and we'll eventually get to some very good-looking photos of some other blues that you may have seen through the years one of the earliest geologists in the area was George Smith in 1903 1903 before automobiles right this guy's working on foot and horseback and he creamed up with a beautiful geologic map north of our Valley to show in red here a round Table Mountain the Tianna way basalt coming through and up and over and heading even through the upper t Attaway River Valley hence the name T Anna web assault and even cropping over at Lake Leola so there's Giotto Waipa salt the host of the Ellensburg blue agates if you're having a hard time picturing a landmark that might be right in the middle of the Tiana Webb assault and you now know the significance of it there we go have you stopped at the Liberty cafe have you enjoyed a cup of coffee and have you looked across the highway Tianna Waipa saw standing almost vertically almost right on end right there and so yes if you've got the proper equipment I suppose you can just blast away at the tea anyway basalt to find Ellensburg blues but we let nature do the work we let nature do the eroding in the blasting for us and we look for this pieces elsewhere you may know this publication Deb you brought it in it's on the shoulder I dropped bought one at the County Museum earlier today written by John Thompson whose dad was a major jeweler in the area and there's this gem no pun intended this gem of a map in this publication showing the original blue agate beds this is Thorpe this is Cle Elum here's peal point but here's our Tianna way basalt working up through red top and then again both shores of Cle Elum lake Tianna web basalt that's why I don't think it's impossible to have some of our glacial activity come down the Yakama and bring a few blue agates but again our big story is here and I've got some photos I want to show here before we wrap it up tonight let's go back then to our Green River Canyon notch which is really the focal point of tonight's lecture and this big broad area of loose rocks just to the south of it that's an alluvial fan if you heard that term before an alluvial fan so alluvial means river carrying loose rocks and the loose rocks are piled in a broad large pile that's shaped like a fan like I could use right now alright so the alluvial fan is forming when we have a steep Ridge next to a broad open Basin and we have a narrow stream cut coming out of the mountains so the river rocks being carried by the stream arc I into this narrow Gorge and then suddenly when we open into the base and those rocks are allowed to spread out and of course the water slows down and drops the rocks that it was carrying so just south of our Green Canyon knotch we have a broad alluvial fan not this photo this is a photo I took in central Idaho showing a classic alluvial fan but this is what we want to visualize perhaps this is maybe too dramatic but our big Ridge north of our current Ridge may be as steep as this bringing our Ellensburg blue agate superhighway and dumping an alluvial fan into the valley so here's our fan set just to the south of our narrow cut the Green River Canyon and this is a beautiful map made just a couple days ago by Jennifer Hackett who lives in town Menashe - mapping comm here's our Green River Canyon here's our broad alluvial fan do you have your bearings let me give you some locations here I think right 97 coming up Dry Creek and up and over and heading to Lauderdale Junction highway 10 highway 90 so here's first Creek which now is taking Ellensburg blue agate material sending it west into thus walk into the Yakima but before first Creek captured this drainage we had our superhighway coming directly in to the northwestern part of so we're right in the neighborhood of some glacial activity Horse Canyon has some ice history so I don't want to say this is 100% stream action but I think it's a majority for our story well the best agates around the world hosted in basalts like the rocks that surround Ellensburg ten and wave is sold in the Columbia River basalts so these examples would be Brazil place quit EDA over Stein in Germany and a few other places but not all blue agates are hosted in basalt some are hosted in other rocks like rhyolite so here's a guy from New Zealand saying that hey there's other blue agates around the world what's the big deal but then he comes around and refines the statement slightly listen carefully there are some blue agates from Brazil I have a very nice example from Tibet what you do and there are some from Europe as well but they tend to be blue bands with red bands white bands but the best Ellensburg blues are blue throughout and so that does make them a little bit special sure so while Ellensburg blues are not unique to Ellensburg they do tend to be the best examples okay worldwide so Richards another guy who comes in and shows stuff occasionally and he was nice enough to take me out with a friend of his George so there's a couple of clips right at the end we're almost done folks so he's been out hunting and he took me one to his favorite spots there's a couple just Raw clips from that fair with me so we're just on a little expedition here and we're trying to figure out this is the right time of year for us so I'm doing a little bit of video taking you there not as is MIT the Green River not and we were on your liberal thing just how many of you know this area holy cow so we're gonna extract it out of here let's see what we're good look at it you wouldn't know it to see it that if you came in here I'm not signing yeah and actually I think it's just a flake of a bigger rock that will give it to lick test it just kind of looks like a piece of that umm chipped up some of the bigger stuff it's just against the ground like that you can see where the color comes out at you nice and I think it's more of a bat dark background color on it that causes it looks a little grey like this guy there's another one amateur hour with the cameras by the way I can never tell how close you can zoom without you turn out the blue into the green that there you go blue into the green I'm not a jeweler I don't have the refined taste that many of you do but even I can appreciate this take the blue agates find a good person a real craftsman to create jewelry and you can really create some stuff that will stay in your family a long long time and I think that's part of the allure here not just the beauty not just the geology but the family history that goes along with this and to go from those shades of blue almost purple down to these other blues that are lighter in color some of the more raw forms that even have little quartz crystals that we're going on the inside of the cavity it's all there and it's all truly spectacular one more time of view at our low Ridge if you want to get a look at a few blue agates and have never seen one before this is just a block away the County Museum there's an elegant collection there but I thank you very much for coming out tonight and we'll look for you next week okay you

Channel: Central Washington University

Views: 136,352

Rating: 4.9343629 out of 5

Keywords: Central Washington University (Organization), Education, Ellensburg (City/Town/Village), Central Washington University, Geology (Field Of Study), Ellensburg Blue Agate, cwu geology, Central Washingtion University, Earthquake, Cwu Geological Sciences, Cwu, Geology, Agate (Material), History, Flood, ellensburg blues, Zentner Geology Lectures Downtown Ellensburg, Ice Age Floods

Id: j8BFvKoabJ0

Length: 50min 5sec (3005 seconds)

Published: Thu Aug 15 2013