A Tour of Texas: Geology and Fossils

[Music] hey everyone randy here with you again i am in texas right now i actually picked up a job shortly after i got back from utah having to do a bunch of sampling of some outcrops in texas so i thought i would combine it with some of the fossil hunting that i wanted to do and right now i'm walking along the shore of lake texoma there's supposed to be some pretty big giant ammonites somewhere around here so i'm gonna see if i can find them so let's go see if we can do that so i'm not kidding when i say things are huge i just looked down saw that laying there on the ground and that's right next to this big piece right here which these pieces already are pretty much bigger than any ammonite i've ever found in my life so this is already pretty exciting and these are just the pieces [Music] so i have to admit guys i was so excited about what i was finding here and collecting that i didn't record much of any video but i did at the end of the trip when i came back so if you hang out until the end of the video you'll get to get the lowdown of the geology here and see some of the other great stuff i found [Applause] [Music] so so welcome to the del rio clay um i'm actually at the lake waco research area and um you can see behind me it this stuff it gets overgrown quite easily so what you're kind of looking for are these steeper sections here that are eroded and what's in here are some pyritic layers that have some really interesting fauna and what i think most people come here for are the prioritized cephalopods here so there's both uh coiled normal ammonites in this stuff and then there's also um turreted heteromorph ammonites in this material which is pretty exciting uh they're really small i actually wrote a series of blog posts about this type of stuff but these pyritic layers they have these diminutive fauna in there so outside of the pyrite layers are sort of typical shelly oyster fauna that you find in here and then these pyritic layers look to appear to me anyways to be largely composed of these sort of diminutive pirate fauna so we're going to see if we can find some stuff here they do have very strict uh collecting limits here you only are allowed to take two fossils away so this is going to be like mostly a show and tell find some cool stuff and show that to you and only take the couple nicest pieces that i find all right so i had to run a good luck here i found a few things that are right next to each other so i'm going to show them to you real quick so that right there is one of the turreted i think it's called like turatellis or something like that i'm sure i pronounce it wrong and i'll have a little pop up there that's what it's actually called but that's it right there that's actually a heteromorph ammonite and you can tell if i can get this to focus um which struggling come on you can do it there we go if i'm not sure if you can see it but there's little bumps on there little ridges on there and that's how you can one of the ways anyways i distinguish these from gastropods so there's one there here's another one here you can see those those bumps on there are are a bit larger and then i found my first coiled ammonite right there as well rather small and again you know there's my fingernail for size so these are quite small just in case you don't believe me how small these things are there's another teeny tiny ammonite right there can't even find it with my finger there we go right there pretty small one i'll leave that there for someone else to take it's fun looking for these things you have to develop a gestalt for it and i feel like i'm walking around and i know what to look for but i'm not finding anything and then i finally do and then they start just popping up everywhere and then when that happens i always have the sinking feeling of like how many tens of these things if not hundreds of these have i walked by in the past hour because i just didn't have the proper search image in my head and but don't leave fossils to go looking for fossils so i think i'll stay here and see what else i can find another one it's rather corroded but it's cool to be finding ammonites just gotta find a real nice one now here is another cool heteromorph that it's blurry there we go now that's blurry again i remember mitch hedberg used to talk about that with sasquatch that every picture of him is out of focus and no one's ever considered that maybe sasquatch is just an out-of-focus blurry creature like this ammonite right now but uh oh just had it there too but anyways that's another heteromorph and uh yeah that's pretty cool it's a little corroded might find some better ones around here but we'll see what we can do okay so this one's a little broken but that's a big big header more if at least for the prioritized stuff i think you can find bigger ones here in the higher unit but that one you can see the knobs on it there so yeah that's the turreted i think it's called turritelli's uh heteromorph ammonite that you can find here in the del rio got gestalt for days there it is that's that's a decent size a little corroded but that's a decent size ammonite right there especially for this stuff you know like i was saying the interesting thing that i find about these pyritic zones is that they seem to demonstrate that not only were the benthic communities stressed by a low oxygen environment but that seemed to extend oftentimes up into the water column as well which is why these predatory ammonites in my opinion anyways also seem to be diminutive in size and do a size comparison of you know this one relative to what i was finding earlier today up north um at lake texoma which will be a pretty um pretty pretty i think incredible to see the difference in size of ammonites you can get again i mean these are different species let's not say some species don't grow larger than others but it's still kind of a fun comparison anyways my understanding these are pretty rare to find here but check this out shark tooth pretty sweet i found one it's worth calling it a day or almost a night on but uh yeah that looks pretty awesome right there well i'm in austin texas now and i'm actually on some of these gravel bars you can see behind me here uh in this business material we're standing on the austin chalk but in these gravel bars you get a bunch of material that is washed out from up above and there's extra gyra um oysters all over the place they're really cool then we're gonna show you that here so if you check this out these gravel bars are just nothing but absolutely tons of these oysters and this is a deal where i'm sure watching me pick these up you're going to be able to see ones that i'm missing but there's one there's another if i can get it just looking at the camera screen i can see more there's another one there check this out it's totally worth it there's a couple there there's some sort of a coral i think there's another one there's another one they're just everywhere you can fill up a bag with these things in a matter of minutes these two are so small i just keep dropping and picking up the same one over and over look at that though and more i don't mind working hard and splitting open tons of rock and finding rare stuff but i'm not gonna lie being able to just sit somewhere and pick through a gravel bar and pick out a gazillion fossils is pretty darn fun too check this one out it's a good sized one for the stuff yeah monster oyster not really but good enough here's another one this is like a great spot to introduce somebody to the hobby of fossil collecting because there's just so much stuff here it's like you're not going to fail at this you're going to find something unless you're really bad i mean if you do come here and you don't find anything it's one of those like you might want to consider a different hobby because you're not cut out for fossil collecting so it said just in a time it took me to record this i got all that right there so yeah good good spot to introduce somebody to fossil collecting if you don't want them to strike out check this one out that's a big in woohoo i also saw somewhere a little piece of charity agate kind of neat [Music] ah okay so i'm looking at stuff i don't normally look at this is much younger this is the carrizo formation behind me which is a sandstone it's kind of paleogene in age and then you can see right here this big unconformity run through there and up above that is this quaternary age gravel and i'm actually interested in the units that are below this but where the exposures are the roads are under construction i can't get there right now but we saw this outcrop and wanted to check it out but what is really interesting is that many of the pebbles that make up this conglomerate are actually agates that are pretty cool looking so check out a few of these so here's one it's kind of hard to see in the sun the coloring on it but there's some reds and green banding agate that goes through there i wonder if we can if that looks a little bit better there i also found this nice piece that's split in half you can actually the way the light hits it you can see the concoidal fracture on there but that looks cool i'm actually going to bring some of these home cut them up on the saw and see if i can put a polished surface on it and see how that comes out there so yeah this is pretty incredible the amount of pebbles that are in here many of them are like these sort of quartz agate pebbles which are pretty phenomenal to look at how exciting when i first looked at this this material here which i thought was bedding actually isn't it's called lease gang which is actually a weathering phenomenon so you're just seeing an artifact of water flow through these deposits and that you know precipitating different minerals and leading to this banding that's in here but you actually you don't have to brush off much of that surface and that goes away there so so there really isn't a whole lot of well-defined bedding in this rock it's kind of a large poorly consolidated massive sandstone in here so this is an interesting spot these are dinosaur tracks that are preserved in some beds within the walnut clay and these occur in the town of leander texas they're not real well known this isn't part of a park or anything like that you just kind of got to figure out where they are and walk up the creek and find them so it's really neat all right so i am in south texas i'm actually not too far from the mexican border and this is the work side of my trip that i'm having to do which is to come out here and collect um eagle ford samples so i can show you this outcrop here real quick so this is one of the outcrops i'm stopping at what you have right here is the buddha limestone or buda depending on where you're from and how you want to pronounce it and then overlying it here here's the contact and this stuff up here that is the eagleford which is known locally as the boccias formation so that's what you're seeing up here so this is a major target of oil drilling for what they call unconventional resources which is basically organic rich mudstone and carbonate fossil fuels oil and gas and so that's what you're looking at here and then this gets you know buried much more more deeper and that's where they're actually drilling wells into this stuff but along this highway in south texas there's pretty spectacular outcrops of it here so i'm out here sampling a bunch of this material um so i got a couple more days of sampling left and then i'll be headed back up to the north there maybe do a little bit of fossil collecting on my way home [Music] [Music] [Music] [Music] [Applause] [Music] hey everyone so i'm out in the finished shale now which is pennsylvanians the gram formation this is actually some of the oldest rocks that i'll be in on this trip they're 300 million years old something like that around that neck of the woods a lot of the cretaceous stuff i was working it was 100 million years old so this stuff is absolutely loaded with fossils if you watch the video that i posted um oh i don't know a month and a half ago or so out in pennsylvania it's time equivalent to these rocks so you're seeing a lot of the same material same fossils this just has some different preservation on it here so um but i did happen to find agony tight which is what i was really excited to come out here and find and i'll show you that now so here it is right there it's a small one a lot of the gonia tights here especially the fully preserved ones that you find are pretty small in this stuff and i've never found these smaller ones in the uh shales back home i've found the medicaceras and i found um panocerus around there but a lot of this other stuff is totally new to me so i'm pretty excited to keep digging around and see what i can find just to give you an idea of what this what this rock looks like you know you can just see there's fossils just laying everywhere in this stuff so i'm pretty stoked on this one it is tiny but the colors on them are unbelievable [Applause] all right so now i'm out in the goodland limestones we're back in the mesozoic here looking for ammonites again you can see the limestone behind me and what i'm doing right now is walking this creek in these gravel bars to see what i can find and let me show you what we're looking for so if you ground here you start scanning these areas you find a lot of partials but every now and then you find a complete one sitting here so that's what i'm looking for that's a trip maker for me right there it's in addition to ammonites there's also these big giant snails and we know i like big giant snails oh oh wow all right good morning everybody i'm on the last day of my trip i'm actually headed back north and i came back to a spot on lake texoma they actually stopped that on the way down here but i was so excited about the spot that i didn't do a whole lot of filming or explaining what exactly it was i was looking at so i wanted to do that real quick what we're in here is the duck creek formation against another cretaceous age rock here and you can see this big limestone pavement right here that i'm standing on so in the lower part of this there's interbedded sort of chalky limestones and shales and then you can see this marley shelly stuff up above here so this is loaded with a lot of like inosyramids and um oysters griffia things like that and then this uh pavement that's down here if i can get show up this is what hosts these big giant ammonites um there's eckinoids in here there's a few heteromorphs if you're lucky to find them and whatnot so that's what we're looking for and i think what people really come here to see are these huge ammonites and i'll see if i can find some and i'll show them to you so here's an example one this one's kind of sea worn here i think from the waves lapping on it you can see my hand there for scale but this is and this isn't even one of the biggest ones that i've seen around here i'll keep finding some and showing them to you but just to give you an idea i'm probably not going to go after this one it's cracked and i don't really like beating the crap out of the rocks here there's enough calving off this bank that you can see here that usually you can find some that don't require a whole lot of destruction in order to extract them check out that monster right there just sitting there in the bank just waiting for a few more waves to bust it out if we walk along you can see a lot of these are sea worn or lake horn i guess there's one in the bank that would have been a nice one if part of it wasn't taken away looks like yeah just something of one there there's the negative of a smaller one so there's actually for as many of these huge ones that exist here there are a number of smaller detailed very nice ammonites that you can find here as well so it's a really interesting spot it's kind of fun to walk along here i guess the lake shore is quite low right now i mean you can see the dried algae on this so usually this whole section here is underwater my understanding according to the floodgage this is about a foot below the normal pool but one of the fishermen i talked to said it was actually about six or seven feet low so um i don't know i mean definitely that being underwater is more than a foot above where the water level is right now so i'd imagine you know it definitely could be more than a foot lower than it normally is so these are just the pieces in the discard piles here's my boot for scale give me an idea how big these are like i said they're just everywhere you can see there's one there there's another one there there's another one there that's the negative of a big iron ceramic clam but uh yeah it's pretty amazing stuff through here you can walk all this in there and there's usually stuff laying around in there echonoids and smaller ammonites and things like that so i might mosey through that a bit too it's interesting that up here you get these very large ones but the inner whirls commonly seem to be i'm assuming crushed and then weathered out um these don't appear to be stein kerns they appear to be sediment filled and i'm wondering if it's hard for sediment to get into those inner worlds and if there's nothing in there to preserve you know that to keep them inflated when the sediment gets compacted i'm sure they just get crushed and then they're really weak in this wave action i'm sure it beats them up and strips those centers of them out pretty easy so there's that i don't know i'm not an expert on on this section here there might be someone else that knows better but that would be my best guess as to why a lot of these larger ones are um are not as well preserved but there's all kinds of goodies in this stuff you'd spend all day here if you didn't have to drive home so if you're patient and you find one that takes a little bit of effort but not much to get out this is the rewards that you can get here um it's gonna be a heck of a time hauling this back to the truck this thing is huge i'll bet it weighs over 100 pounds but it's a complete one it was right there on the shore the whole top of it was exposed you can actually see some encrusting things on here and whatnot so it's a really neat piece i'm really glad i got it it's a great way to end this trip so that's it guys um i'm headed back i got about a two day back to pennsylvania i really hope that you enjoyed this brief look at all the spots that i hit in in texas i came in here to lake texoma went down to waco did some collecting there then down to the austin area and did a little bit of work looking for the eagleford there and some collecting they went out to del rio and west of there looking at the eagle fur which is the bokeh's formation and sampled that also spent some time a little bit east of of austin looking at really high you know pleistocene and slightly older deposits there of the wilcox group and then back to waco then to the fort worth area looking for fossils there and then finally back here to lake texoma so it's been quite the tour for me i really enjoyed it and uh i hope you have too and hopefully learn something interesting about it so long guys thanks [Music] you

Channel: Randy Blood

Views: 28,944

Keywords: ammonite, fossils, geology

Id: MgQqPuPyvYI

Length: 26min 9sec (1569 seconds)

Published: Mon Mar 29 2021