Hill County creek, June 10th

[BudB]

I am working again these days, but on Wednesday, I got off early enough that I made a trip to a creek in northern Hill County. Its limestone walls are full of fossils, but the limestone is very hard. It is obvious that I need to get better at chiseling fossils out of limestone. I could get lots of practice in this creek. Macrostrat shows the area where I was as being right on the border of the Fredericksburg and Washita Groups. 

The first thing I noticed about this creek was how many Gryphaea (devil's toenail) oysters there were. Most are pretty small, but they are everywhere. There are more of them in the creek than all other fossils combined, including lots of limestone pieces just full of small ones like the one in this photo.

 

 

[BudB]

I should have been paying better attention when I chiseled out this piece of limestone with half an echinoid in it. I never found another echinoid at all.
 

 

[BudB]

Getting a large ammonite out of the limestone is really tough. I may need to bring a bigger hammer next time.
 

 

[BudB]

This ammonite fragment was one of the few fossils I found that was loose, not embedded in the limestone. As straight as the fragment is, I'm thinking it must be from a heteromorphic ammonite. I wish I could have found the rest of it. I notice that some of the rock in it is the gray limestone the creek walls are full of, but some of the inside of it more closely matches the tan loose rocks that were everywhere between the topsoil and the gray limestone. It made me wonder if it came from where these two different rock layers meet.
 

 

[BudB]

Anyone recognize the fossil in the middle of this piece of limestone? A coral, maybe?
 

 

[BudB]

And of course I picked up some gastropods, most with varying amounts of limestone attached. I figure when I get around to trying to use a dremel or air scribe to remove limestone from fossils, these will be good practice pieces.
 

 

[BudB]

There were veins like this fossil running all through the limestone. I didn't try to excavate this one. Anyone know what it is?

 

 

[erose]

Looks like you are in the Fredericksburg Group.  But you might try this online geo map and read the descriptions to better discern the formation.  The Heteromorph is IMHO the most exciting find.

 

The branching things look like burrows, trace fossils.

 

Cool stuff.

[BudB]

3 hours ago, erose said:

Looks like you are in the Fredericksburg Group.  But you might try this online geo map and read the descriptions to better discern the formation.  The Heteromorph is IMHO the most exciting find.

 

The branching things look like burrows, trace fossils.

 

Cool stuff.

 

Thanks. Agreed on the heteromorph.

 

I used the map at macrostrat.org in satellite mode on my PC to try to ascertain what formation I was in. I hiked a half mile of the creek, and the map literally shows half of that in the Washita Group and half of it in Fredericksburg. I know these maps aren't exact, and the two formations have such similar descriptions, I wondered which one I was in.

 

I need to come back to this creek when I have more time. Three hours and seeing half a mile of the creek was just enough to tell me there are some great finds there.

[Creek - Don]

18 hours ago, BudB said:

And of course I picked up some gastropods, most with varying amounts of limestone attached. I figure when I get around to trying to use a dremel or air scribe to remove limestone from fossils, these will be good practice pieces.
 

 

Nice size gastropods. There are some big gastropods size of hand near NW of Austin, Texas.

[BudB]

59 minutes ago, Creek - Don said:

Nice size gastropods. There are some big gastropods size of hand near NW of Austin, Texas.

 

Yes, I'm used to the tiny gastropods I've found at NSR and Post Oak Creek. The only other place I've found bigger gastropods like these are at the Benbrook spillway, and it's so picked over you don't find much else.

 

I would enjoy some trips to other parts of the state when I can find the time.

[erose]

1 hour ago, BudB said:

 

Thanks. Agreed on the heteromorph.

 

I used the map at macrostrat.org in satellite mode on my PC to try to ascertain what formation I was in. I hiked a half mile of the creek, and the map literally shows half of that in the Washita Group and half of it in Fredericksburg. I know these maps aren't exact, and the two formations have such similar descriptions, I wondered which one I was in.

 

I need to come back to this creek when I have more time. Three hours and seeing half a mile of the creek was just enough to tell me there are some great finds there.

The Walnut, Comanche Peak, Goodland and Kiamichi share some similar fossils. 

[Archie]

Awesome finds, I especially like the heteromorph ammonite and the gastropds! Scutch hammers are really useful for removing fossils from big blocks of limestone, it can be very time consuming though. If the landowner doesnt mind a battery angle grinder is always great! 

[Joe Salande]

Nice finds! Congrats.

Joe