vertman Posted July 4, 2013 Author Share Posted July 4, 2013 Hours 37 - 43 Tuesday July 2 2013 and Wednesday July 3 2013 So I had pretty much exhausted the productive vertebrate zone that I found a few weeks ago. I moved up toward the middle then the top of the Austin Chalk over the last few outings. I have been probing for more promising zones. Then something occured to me. Perhaps I could look at the geologic map and identify outcrops that lie in the same relative position (as the productive zone) within the formation. It was one of those rare times when something was as easy and as logical as it seemed. Within a few moments of research I had identified a likely looking spot and on Tuesday and Wednesday I was able to hit almost half of that spot. Results of this collecting are not earth-shattering by any means. However a steady trickle of vertebrate fossils found their way into my collecting bag. I also found a very cool fossil that I have never seen from the Austin. It could end up being my find of the project thus far. I also know that I am not the first to hit this site. Evidence of a specimen's removal with a rock saw was still fresh enough to be quite evident. A tip of the cap to you sir or madame for beating me to something good. I noticed there is not nearly as much "slick-n-slide" calcite at this spot. In fact I don't recall seeing any. There are a few decent Inoceramus but the molluscs are largely missing from this site as well. There are a fair number of small oysters whose identify escapes me at this moment. I saw a 3 to 4 inch thick bentonite seam in the wall. I know that those seams exist but I find them really cool. I can't help but wonder if some of those seams correlate exactly to some of the bentonite seams in the Niobrara out in western Kansas. I start off with a couple of site images including one of a bentonite seam. Link to comment Share on other sites More sharing options...
vertman Posted July 4, 2013 Author Share Posted July 4, 2013 Early in the day on Tuesday I began to find shark teeth. I thought oh boy this is going to be a great haul. It turns out the number of teeth are fairly limited but that is ok. I found several Ptychodus mortoni teeth. These guys seemed to have major root damage. I guess it must be due to the circumstances under which they fossilized. Once I accidentally went down-section too far and stumbled into the Basal Atco formation. This is one of the best known Texas geologic formations and contains a lot of shark teeth. I thought to myself well that's nice I will remember this spot for later. I felt I needed to get back into the Austin quickly. What is wrong with me? I just bypassed a decent looking Atco spot for more Austin Chalk? Oh well at least I did find a quick P. whipplei tooth while I was there. Back in the Austin a number of Squalicorax teeth came to light. I will call them all S. falcatus for now until somebody corrects me. Below are some images of the shark teeth I found. Link to comment Share on other sites More sharing options...
vertman Posted July 4, 2013 Author Share Posted July 4, 2013 There is one Ptychodus "tooth" that I still can't decide about. When I dug him out I thought I had found a symphiseal (sp?) tooth. Now I can't decide if it is even a tooth. An image of it follows along with some of the Squalicorax teeth and the lone P. whipplei that I grabbed from the Atco. Link to comment Share on other sites More sharing options...
vertman Posted July 4, 2013 Author Share Posted July 4, 2013 Here are a few more Squalicorax images. There also seemed to be a pretty large number of very small fish vertebrae present at this site. I have to admit to you that more than one of these little guys shattered into a thousand pieces at my hands. I have been swinging a miner's pick or a sledge or a rock hammer a lot lately and my wrists are killing me. It made extracting some of these small delicate little guys difficult. Images follow. Link to comment Share on other sites More sharing options...
vertman Posted July 4, 2013 Author Share Posted July 4, 2013 At one point I did find a cluster of fish scales on a slab. I am not sure if the slab came from above or below the Austin/Atco contact. It contains very partial remains of a little fish which will probably remain nameless forever. A very neat fossil feature can be observed at this site. There are actually remains of tree bark and branches completely contained within the Austin. I believe this is referred to as "lignitized wood" It is incredibly cool and is a very important "signal" fossil as it gives a real clue to the depositional environment at the time. I believe the presence of this wood indicates a more shallow sea. It signals a regressive event where the ocean levels decreased. This means a lot more life was frolicing about living and dying. More life then means more fossils for us to find now. More images: Link to comment Share on other sites More sharing options...
vertman Posted July 4, 2013 Author Share Posted July 4, 2013 I did find a couple of "odds and ends" type fossils as well. One was a shark tooth blade sticking straight out of the chalk. It was pretty cool. I dug carefully and deeply but there were no roots present. I believe this blade belongs to the shark Cretolamna appendiculata but I could be wrong about that. I also found what appears to be a vertebral process to somebody. I am guessing it may be reptilian. The process was in place and the front where the vertebral centrum would have been was completely gone. Link to comment Share on other sites More sharing options...
vertman Posted July 4, 2013 Author Share Posted July 4, 2013 My favorite and probably the most interesting find over the last couple of days is what appears to be the remants of the pen or rhacis (guard) of a squid. I would not even venture a guess at the genus of this guy. I have not heard of other examples of squids being found in the Austin Chalk so Shawn Hamm and I are currently researching how common or uncommon this find may be. I have found a few examples of Niobrarateuthis in western Kansas including one with the impressions of the ink sacks in place. That specimen was donated to the Sternberg. But this is the first squid I have recovered from the Austin. I plan on returning to hit the remaining portions of this site and then I will venture upward to a spot where the contact between the Austin and Taylor groups is exposed. I also plan on hitting a possible ammonite zone soon. Link to comment Share on other sites More sharing options...
vertman Posted July 4, 2013 Author Share Posted July 4, 2013 This project has proven to be a lot more fun that I thought it would be. Collectible and meaningful fossils have come around much more often than I thought they would. I can hear my buddy Brent somwhere chuckling and saying "see I told you there were many good fossils in the Austin". We still have 57 hours of work to do but so far it looks like he was right. I look foward to the remaining time. Untiil then 57 hours remaining. Link to comment Share on other sites More sharing options...
JohnJ Posted July 4, 2013 Share Posted July 4, 2013 .... Once I accidentally went down-section too far and stumbled into the Basal Atco formation. This is one of the best known Texas geologic formations and contains a lot of shark teeth. I thought to myself well that's nice I will remember this spot for later. I felt I needed to get back into the Austin quickly. What is wrong with me? I just bypassed a decent looking Atco spot for more Austin Chalk? .... I wouldn't be too hard on yourself, Richard. According to Young and Woodruff (1985) in Austin Chalk In Its Type Area - Stratigraphy and Structure, the Atco Formation is the base formation of the Austin Division or Austin Chalk. It's been a pleasure following your 'journey' so far. Looking forward to the next 57 hours and learning more about your finds. The human mind has the ability to believe anything is true. - JJ Link to comment Share on other sites More sharing options...
Ludwigia Posted July 4, 2013 Share Posted July 4, 2013 This is really interesting! Looking forward to more! Greetings from the Lake of Constance. Roger http://www.steinkern.de/ Link to comment Share on other sites More sharing options...
Uncle Siphuncle Posted July 4, 2013 Share Posted July 4, 2013 a classic case of reading between the lines of the geo map, something i do all the time. success comes most frequently to those who constantly deduce, follow, and exploit trends. Grüße, Daniel A. Wöhr aus Südtexas "To the motivated go the spoils." Link to comment Share on other sites More sharing options...
Ludwigia Posted July 4, 2013 Share Posted July 4, 2013 a classic case of reading between the lines of the geo map, something i do all the time. success comes most frequently to those who constantly deduce, follow, and exploit trends. ...and also sometimes use the help of a good pick and shovel... Greetings from the Lake of Constance. Roger http://www.steinkern.de/ Link to comment Share on other sites More sharing options...
Uncle Siphuncle Posted July 4, 2013 Share Posted July 4, 2013 ...or bring a young strongback for the yeoman's work... Grüße, Daniel A. Wöhr aus Südtexas "To the motivated go the spoils." Link to comment Share on other sites More sharing options...
Ludwigia Posted July 4, 2013 Share Posted July 4, 2013 Ganz richtig! Greetings from the Lake of Constance. Roger http://www.steinkern.de/ Link to comment Share on other sites More sharing options...
vertman Posted July 4, 2013 Author Share Posted July 4, 2013 I wouldn't be too hard on yourself, Richard. According to Young and Woodruff (1985) in Austin Chalk In Its Type Area - Stratigraphy and Structure, the Atco Formation is the base formation of the Austin Division or Austin Chalk. It's been a pleasure following your 'journey' so far. Looking forward to the next 57 hours and learning more about your finds. Thanks John. I know the Basal Atco is considered a part of the Austin Group. What I was lamenting a bit was my own desire to immediately jump out of a very fruitful fossil bearing unit like the Atco in favor of the Austin Chalk proper which is considered to be pretty barren at least in the Dallas/Ft. Worth area. I can honestly say this is the very first time in my history of collecting that I have intentionally left the Atco for the Austin. I don't know me anymore!!! Link to comment Share on other sites More sharing options...
vertman Posted July 4, 2013 Author Share Posted July 4, 2013 Thanks John. I know the Basal Atco is considered a part of the Austin Group. What I was lamenting a bit was my own desire to immediately jump out of a very fruitful fossil bearing unit like the Atco in favor of the Austin Chalk proper which is considered to be pretty barren at least in the Dallas/Ft. Worth area. I can honestly say this is the very first time in my history of collecting that I have intentionally left the Atco for the Austin. I don't know me anymore!!! It has been one of my "rules" throughout this experiment that the Basal Atco is not included. All of the Austin collecting included in this 100 hours is above that unit. Link to comment Share on other sites More sharing options...
vertman Posted July 5, 2013 Author Share Posted July 5, 2013 Hours 44 & 45 Thursday July 4 2013 Today I spent a couple of hours on the same outcrop as the last couple of days while my girls went shopping for shoes. Free tip to all you hubbys and gonna be hubbys some day...allowing the lady folk to go shopping is a great way to buy time in the field...even when they come back with multiple pair of shoes and several outfits each. Ouch! Anyway today was not exactly like the Independence Day Massacre but I did find a few things and traveled a really cool geologic path. I have been collecting in what I believe to be a regressive sequence of the Austin Chalk. Indicators show a lower sea level and the presence of a lot of different vertebrate fossils support that. I did find a piece of a fish fin so badly preserved that I will never learn his identify. I was also lucky enough to stumble onto a couple more shark teeth. The first was another example of Ptychodus mortoni. It was sticking out of the chalk just waiting to be plucked. Unfortunately its root was virtually all gone much like most of the others I have found at this site. The second tooth was a very nice Squalicorax falcatus. It was setting vertically in a crack in the chalk. It is the nicest tooth I have found so far at this spot. The very cool thing about today was that I literally walked through the top of the regressive sequence and into the remains of a transgressive event that must have expanded the Western Interior Seaway greatly. One moment I was seeing the indicators of a more shallow water environment and was still finding some fish and shark remains. The next minute the giant clams and oysters such as Inoceramus were all over the place. I mentioned in a post yesterday how strange I thought it was that these giants are missing almost completly from the lower end of this site. At the same time the clam and oyster content increased I also noticed the vertical fracturing and in-filling with "slick-n-slide" calcite also became very common. I don't believe that calcite is an indicator of the deeper water environment. My understanding is that crack infilling can occur anywhere throughout the Austin and also in most other limestone units. There were literally zero vertebrate fossils above this transition. I found this sequence to be extremely cool and educational. Tomorrow I will be playing field trip host to a gentlemen from Tulsa. Years ago he made the arrangements to get some of us into a rock quarry in southwest Oklahoma. Because of his efforts people like Brent Dunn and Mark McKinzie and Dan Woehr all found species of amphibians and reptiles brand new to science. I got to collect a quarry that I grew up about 40 minutes from. This is my first chance to try to repay him for his kindness and effort. I hope I am able to put him onto some quality north Texas fossils. My Austin quest will resume either this weekend or possibly next. Until then 55 hours remaining... Link to comment Share on other sites More sharing options...
sward Posted July 5, 2013 Share Posted July 5, 2013 ... A very neat fossil feature can be observed at this site. There are actually remains of tree bark and branches completely contained within the Austin. I believe this is referred to as "lignitized wood" It is incredibly cool and is a very important "signal" fossil as it gives a real clue to the depositional environment at the time. I believe the presence of this wood indicates a more shallow sea. It signals a regressive event where the ocean levels decreased. This means a lot more life was frolicing about living and dying. More life then means more fossils for us to find now... Richard, Your continued perseverance is obviously paying off. I'm amazed at the amount of vert material you've already found in this "barren" formation, and now you're finding plant material. And to boot, you're not even half way through your experiment. I see a scientific paper being written once you've completed your experiment. Congratulations! SWardSoutheast Missouri (formerly Dallas/Ft. Worth, TX) USA Link to comment Share on other sites More sharing options...
vertman Posted July 14, 2013 Author Share Posted July 14, 2013 (edited) Hours 46 - 50 Saturday July 13 2013 Well I guess things have to even out eventually in this adventure. The Austin Chalk being the fickle dance partner that it is; it reared up and got a bit of revenge on me for some of the recent finds I had been lucky enough to make. My buddy Shawn Hamm had become seduced by the Austin after reading some of my trip reports so he and his girlfriend Gigi made their way down from Wichita for a day of Austin fun. We hit 4 different Austin locations pretty hard and ended up with very limited returns. I was able to take advantage of Shawn being present as he provided some very interesting and much-needed perspective on the geology that I had been seeing. Late in the afternoon we abandoned the Austin quest so that he and Gigi could find a few fossils in the Arcadia Park and Kamp Ranch members of the underlying Eagle Ford Group. Although finds were limited I believe it was a very valuable day of knowledge gathering. It turns out the most productive sites that I have found are just below the upper boundary of the Atco Member of the Austin Chalk. Everyone knows about the base of the Atco unit or the Basal Atco which is at the boundary of the Austin Group and the underlying Eagle Ford Group. However it came as a bit of a surprise to me that the top of this unit also contains vertebrate remains with some regularity. Shawn was also able to confirm the unit that the squid fossil I recently reported came from. It seems to have come from near the top of the Atco Member as well. I still want to say this example may represent the genus Niobrateuthesis. Shawn is checking to see how commonly these guys have been reported from units within the Austin or if they have been at all. I guess time will tell on that. Beginner's luck was on the side of Gigi this day as she found her first ever shark tooth. It turned out to be an example of a Scapanarhynchus texanus. It was the first example of this shark that has been found during this study. Well done Gigi! A couple images of her find are attached. I was pretty much shut out of finds for the entire day. It is almost as if the Austin were making fun of me for bringing Shawn and Gigi into the experience. It was saying "see here my man I still control this thing you are just a guest". I did manage to locate what I believe to be an ammonite. More detail on that follows below. Edited July 14, 2013 by vertman Link to comment Share on other sites More sharing options...
vertman Posted July 14, 2013 Author Share Posted July 14, 2013 (edited) We collected a small part of a location I had been saving for when I had a collecting buddy with me. I had very high hopes and expectations for this location as it exposes about the top 8-9 feet of the previously mentioned Atco Member of the Austin Chalk and also many feet of the overlying member whose name I don't remember right now. I want to say Vinson but I know that is not right. I think the Vinson is missing almost entirely in the Dallas area for some reason. I believe it is the member above the Vinson that is present here. This is the location where Gigi found her shark tooth. I also found what I believe to be an ammonite resembling Pachydiscus paulsoni sticking out of a solid limestone wall. I am not sure of the ID of this specimen. To be frank I am not even 100% sure this is an ammonite but I believe that it is. Shawn and I both took turns beating on the wall and managed to expose the specimen a bit more. But this is some of the absolute hardest rock I have ever dug into. After an hour we both gave up and collected the rest of the outcrop. I will go back there a few times and work on it an hour or so at a time until it comes free. I have attached an image of it sticking out as well as an image of Shawn having a go at whacking the specimen free. I also included an image of more of the lignitized wood that I have been seeing at some of the Austin locations. I like this stuff. It is cool to think of tree limbs and branches that floated out to sea so long ago. We jumped into another creek location that I have located by using the same logic that I used to find the second productive creek last time. This time the outcrop belt apparently veers sharply to the north and east. When we jumped into the creek we jumped smack into the middle of the Arcadia Park Member of the Eagle Ford Group. We knew this was below the contact with the Austin Chalk and Shawn was finding a few small shark teeth. So we headed up-section (eastward). We walked and we walked and we walked and we walked and we checked Google Maps and we walked... You get the idea. We never made it to the Austin at this particular location. I will need to check it out again some day soon. It is getting a bit harder for me to write these wrap-ups. Things are starting to seem and feel very redundant. I am now exactly 1/2 way finished with this collecting. I am torn about whether I am happy about this or whether I will miss it. I know I need to concentrate on the middle and upper parts of the formation. I have not spent nearly enough time in those areas. I am hoping more cool finds will come from this. I don't know when that will happen. I do know that something good is out there waiting for me...just around the next corner. I can feel it. I can't wait to get out there the next time. Until then 50 hours remaining... Edited July 14, 2013 by vertman Link to comment Share on other sites More sharing options...
Auspex Posted July 14, 2013 Share Posted July 14, 2013 It's a great ride so far! "There has been an alarming increase in the number of things I know nothing about." - Ashleigh Ellwood Brilliant “Try to learn something about everything and everything about something.” - Thomas Henry Huxley >Paleontology is an evolving science. >May your wonders never cease! Link to comment Share on other sites More sharing options...
Uncle Siphuncle Posted July 14, 2013 Share Posted July 14, 2013 when u need a break, richard, let me take you out down south! maybe august... Grüße, Daniel A. Wöhr aus Südtexas "To the motivated go the spoils." Link to comment Share on other sites More sharing options...
vertman Posted July 14, 2013 Author Share Posted July 14, 2013 Dan I will definitely take you up on that! We need to do some prospecting up this way as well. Link to comment Share on other sites More sharing options...
PFOOLEY Posted July 16, 2013 Share Posted July 16, 2013 Can't wait for the latter 50! "I am glad I shall never be young without wild country to be young in. Of what avail are forty freedoms without a blank spot on the map?" ~Aldo Leopold (1887-1948) New Mexico Museum of Natural History Bulletins Link to comment Share on other sites More sharing options...
vertman Posted August 5, 2013 Author Share Posted August 5, 2013 (edited) Hours 51 & 52 Sunday August 3 2013 It has been a few weeks since I have been able to collect anything so my Austin Project has hit a bit of a rut. Hopefully I can change that and get out a lot in the next few weeks. I am beginning to be able to smell the finish line on this thing. I do plan on spending the next 25-30 hours collecting the middle third of the Austin. I forget the member name right now but I expect it to be very highly fossil-free. We will see. I had a few hours today so I jumped out into a spot near my house. It was a cool 104 degrees when I started. I love the heat so it doesn't really bother me. But I think it was too hot for the fossils to come out. In the couple hours the specimen in the attached images is really the only interesting thing I saw. Since I am in the middle Austin there are a ton of huge fragmentary clams and oysters. I should get around to collecting a few of those to include in the faunal listing I have collected during this project. I would like to ask your opinions. Is the specimen in these images a burrow or is it a Baculites? I don't see any ornamentation at all on the specimen that would be a dead giveaway. I think I am leaning toward it being a burrow. Your thoughts are appreciated. This piece is about 8 inches in length. Hopefully I will get to collect a lot more very soon. Until then 48 hours remaining... Edited August 5, 2013 by vertman Link to comment Share on other sites More sharing options...
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