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Wilcox Group, Texas (Guadeloupe County) finds and mysteries


KingsburyFossilHunter

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Hi everyone!

 

For the last few months I have been finding lots of fossil imprints in mixed chert cobble on a artist residency/farm in Kingsbury, Texas near Seguin (in Guadeloupe county). They are digging up some of the cobble/gravel to line the roads and walkways on the farm, which means that everything gets spread out nicely! Plus there is the 'quarry' itself. The USGS map says that the area is Wilcox Group, undivided, and/or Willis Formation, and I am looking at mudstone, chert, a little bit of sandstone, gravel, some petrified wood. In terms of age I think it matches up with Eocene but could go back a little farther, especially since some stuff may have been deposited by a nearby creek. For Wilcox Group USGS says AGE_MINPhanerozoic - Cenozoic - Tertiary-Paleogene - Early-Eocene

AGE_MAXPhanerozoic - Cenozoic - Tertiary-Paleogene - Late-Paleocene. I am using the two classic Texas references to ID general fossil type, Matthew's Texas Fossils and also Finsley's A Field Guide to Fossils of Texas, and also deeply perusing thefossilforum.com site.

 

I think the below is a stromatolite, then the rest are pelecypod impressions of various types. Except for that last photo in this post, I am guessing that is just a sideways cross section. I am curious as to your opinions... it has been really fun to look and to find these! I will add more images in subsequent posts.

 

 

 

Stromatolite.jpg

Pelecypods.jpg

Pelecypods2.jpg

Pelecypods(1).jpg

Pelecypod3.jpg

PelecyodSideways_.jpg

Edited by KingsburyFossilHunter
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And here is a nice Neithea Sp. impression. Also mixed Pelecypod/Gastropod and straight up gastropod impressions or cross sections...

NeitheaSp.jpg

MixedGastropodPelecypodMatrix.jpg

Gastropod.jpg

GastropodImprints.jpg

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Here are some maybe's: a fish impression? trochosmilia or rudist (in a piece of petrified wood?)? The third photo is a mystery, the left rock might not be a fossil at all. But I have other strange imprints (see fourth photo). The last photo is so odd - I am leaning towards chert nodule - but could it be a coprolite?

Fish_.jpg

TrochosmiliaorRudist.jpg

Geofact_Worm_Cephalopod_.jpg

cephalopods_.jpg

ChertNoduleorCoprolite_.jpg

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These ftwo photos I initially thought were coral, but may actually be bone fragments, they have some very smooth sides to them. One in the mixed photo reminds me of a patella.

Bone_.jpg

BonePatella_.jpg

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First image shows a closeup bottom left of what I think is coral, also there's an interesting spiral shape on the other side of the rock. I am not sure what second image is of...both coral?

coral_(1).jpg

Coral_.jpg

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And here's the best most awesome mysteries. Sorry for so many photos in this topic. These are the ones I need the most help with.

Mystery: plant or animal? or just concretions?

Mystery 2: found nearby in a cattle tank. Coral or fish? Check out the concave area in right image, looks almost like fish skin, magnification reveals tiny white triangular pyramids aka tetrahedrons, either crystallization or something else...but I haven't found any other crystallization of this type, only chalcedony.

Mystery 3: We thought the one on the right was a human artifact until we found the rock on the left. What could make these kind of embedded circles? Geology or fossil?

Mystery 5: what could this draping type of imprint (on right of left image) be?

 

Thanks for your eyes. I have a few more treats to photo but not till I have time next week.

Mystery.jpg

Mystery2.jpg

Mystery3.jpg

Mystery5.jpg

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Wondering if this stuff was all washed downstream from the Edwards fm.

Grüße,

Daniel A. Wöhr aus Südtexas

"To the motivated go the spoils."

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Hey Uncle Siphuncle! I enjoyed looking at your greater S.A. posts!

 

Re Edwards, that's a good question.

 

The Willis formation according to USGS  is "Clay, silt, sand, siliceous granule to pebble gravel, some petrified wood; sand coarser than younger units, noncalcareous; deeply weathered, locally cemented by iron oxide; fluvitile; forms north-facing scarp. On Seguin Sheet (1974) thickness 100+- ft. On Austin 4 x 6-degree sheet (Moore and Wermund, 1993) unit consists of 1) channel facies--alluvial pebble gravel and sand, lt. gray to orange-brown, orange, gravelly coarse to fine sand which lenses of red, sandy silt and white to gray clay 10-60 m thick, pebbles mostly quartz, some chert and petrified wood, and 2) overbank facies--alluvial silt and clay made of brown, yellow, orange, fine silt and clay are intermixed and interbedded." https://mrdata.usgs.gov/geology/state/sgmc-unit.php?unit=TXPOw;0

 

I also saw Reklaw Formation, " sandstone and clay, sandst. fine to med grained, abdt hematite, muscovite, glauconite, friable to highly indurated, crossbedded, some pelecypod casts; clay silty, lignitic; thickness about 50-80 ft." listed at some point when researching this.

https://mrdata.usgs.gov/geology/state/sgmc-unit.php?unit=TXEOr;0

 

However, I'm not finding a ton of casts, mostly molds.

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All of these pieces look stream tumbled, so they are older rock that has been washed down from another older formation than what they were found in.  ie... a Tertiary gravel bed is made from mesozoic (or older) rock.

Darwin said: " Man sprang from monkeys."

Will Rogers said: " Some of them didn't spring far enough."

 

My Fossil collection - My Mineral collection

My favorite thread on TFF.

 

 

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