Jump to content
sybaris

St Leon Indiana Road Cut

Recommended Posts

sybaris

I had heard a lot about St Leon and since it was only two hours from my home I decided to spend Monday there. I arrived just before noon and was the only person in sight. I could tell it had been recently visited and expected there to be others since it was a holiday but I remained the only hunter all day.

I had read in other reports that visitors are quite astonished at the magnitude of the cut and volume of loose material. Yes, it is a bit overwhelming. It reminded me of old South Carolina oyster bars that had mounds of shells under the houses from patrons throwing the shells through the holes in the floor.

In another report it was said that a hunter needn't venture too far up the hillside due to the loose material that had fallen from above however, I noticed that specimens in the lower material seemed a bit worn and fractured. So I made my way up to the level that seemed promising for less weathered specimens and was not disappointed. What surprised me though is how high I went. I'm guessing in that area there's not much distance between the topsoil and fossil bearing stone. Still, most of my finds were loose or easily released with my rock hammer or hammer and chisel.

I had originally come for just one thing, trilobites, but couldn't resist picking up some of the common fossils of the area. I'm by no means an expert at correctly naming my finds so here goes;

1,2 & 3) horn corals (Grewingkia canadensis)

4) Lepidocyclus capax

5) Part of a Flexi' (Yay! My first.......piece)

6) gastropod molds

7) haven't figured out the genus

8) cephalopod segments??

9) some kind of encrusting coral

10) bryozoa?? Against the back drop of jagged stone and brachiopods the spherical shape really stood out. Funny thing is that it was the only one I saw all day

I spent about 2 1/2 hours on the east side of the road and about half an hour on the west. After 3 hours everything started looking the same and figured I wasn't doing myself any good and packed it in.

On my way out I noticed a sign by the roadside, something about the area being state property and no digging allowed. I mention this because in another thread there was some discussion about a law passed in Indiana preventing fossil collecting from road cuts. I'm thinking that if collecting wasn't allowed it would be so stated so I take it as you can but just don't dig and at St Leon you wouldn't have to.

post-10095-0-61427900-1349818431_thumb.jpg

Share this post


Link to post
Share on other sites
Bullsnake

Very cool finds! Thanks for the numbering system, too. :thumbsu:

Share this post


Link to post
Share on other sites
erose

That road cut exposes almost all of the Richmond group and the various formations have different types of preservation. You go from layers with good preservation to rubbly broken and back again a few times. The fossils are not necessarily better preserved due to having travelled less down the slope.

Your IDs look good except I think the #9 "encrusting coral" is actually a bryozoan. The photo will not enlarge enough to see the detail and the same goes for #10. The other brachiopods are probably Strophomena.

That "no digging" sign is there because about 10-12 years back some overzealous collectors dug out a huge section and caused damage (debris making it's way into the drainage and onto the road) but I have been there when an IN Trooper stopped and just asked a few folks to pull their cars a bit further off the road. But we were not told to leave. FYI: I believe the diggers did get some incredible and rare trilobites for their efforts. I'm not suggesting digging but you should know that this site produces more than just Flexicalymene and Isotelus trilobites.

Share this post


Link to post
Share on other sites
squalicorax

Great finds from one of my favorite sites

Share this post


Link to post
Share on other sites
fossilnoob

Nicely done! Always a good spot to go! I found my first trilo there earlier this year within ten minutes after three trips there! Congrats!

Share this post


Link to post
Share on other sites
Uncle Siphuncle

great site, best results on trilos if you keep your schedule loose enough to show up immediately after a hard rain.

Share this post


Link to post
Share on other sites
Wrangellian

:drool: Yet another sweet collecting spot... you guys in the Midwest have it good for Paleozoic stuff. I wonder how many residents of that area are uninterested because there are no dinosaurs, wishing they lived out west.

BTW Erose, thanks for the link - some spectacular eye-candy and a well laid out site.

Edited by Wrangellian

Share this post


Link to post
Share on other sites
Missourian

Nice pieces. I wish our western Missouri Ordovician was more than just massive dolomite.

Share this post


Link to post
Share on other sites
Rob Russell

Nice finds from a fantastic site. I look forward to returning there in a few weeks myself. Thanks for sharing!

Share this post


Link to post
Share on other sites
Bev

Awesome Finds!

#9 If I found that here (limestone, Galena, Ordivacian) I would see it as a sunflower coral/algea official name starts with rep... Just a thought :)

Share this post


Link to post
Share on other sites
erose

Receptaculites is not known from the Cincinnatian and would be an unusual find. There are a number of frondose and massive bryozoans that have those raised bumps (mammulata?) common in the rocks at St Leon. It would take a better photograph, tighter stratigraphic info and probably thin sections to really nail it. You can sometimes get to some level of generic ID via elimination depending on the number of known genera for a formation. But the Cinci contains hundreds of described bryozoan species.

With that said could we get better photos of items 9 & 10 please?

Share this post


Link to post
Share on other sites
Crinoid Queen

YA I LOVE St. Leon!!!!! Nice Stuff!! I wanna dig i Giant hole to look but alas it is dangerous for every one who drives by every day that is why we must be satisfied with surface collection. That is why you get into the ruts the rain makes NATURAL DIGGING :D I cannot wait to go there in a few weeks after all the rain we have had. I hope it pours there the night before our trip! Every time i have been there it has not rained for 3 mo before hand LOL. But I still manage to always find some great trilos! I wish I was Closer I would be there every weekend!

-CQ

Share this post


Link to post
Share on other sites
Rob Russell

I recall you finding a nice little crinoid there also CQ. On that 250,000 Lb rock that took a team effort to get down the hill and in the trunk. :P

Share this post


Link to post
Share on other sites
sybaris

Thanks for all the replies

The suggestion of going back there after a good rain reminds me of how I found the trilobite. It had rained in the area several days prior to my visit and I was looking in a trough created by runoff. It was still very damp and the trilobite was darkened by the moisture so it really stood out from all the other material. I think I'll start carrying a spray bottle.

I took some additional photo's of #9 and #10. I don't have a real good camera for taking macro's but I think at least some additional detail of the coral can be seen. After re-inspection I think now that #10 is a mollusk.

post-10095-0-83702500-1350155132_thumb.jpg

post-10095-0-97940900-1350155620_thumb.jpg

Share this post


Link to post
Share on other sites
erose

Hard to say on #10. A mollusc internal mold is a possibility for sure. But #9 is actually one of the few bryozoans you can at least ID to genus. Those star-shaped bumps are indicative of Constellaria. There are at least three species that could be found in the layers there but as far as I know no other genus with that same star pattern.

Share this post


Link to post
Share on other sites
sward

Some very nice finds!

It sounds like an outstanding place to hunt. It must be one massive roadcut. Can someone take a few pics of it and post them? I would love to see what it looks like.

Here in north TX, it's flat enough that we don't get many roadcuts.

Share this post


Link to post
Share on other sites
lotsofpets

http://drydredgers.org/trip201105p1.htm

Here is one. You can click on previous years for more information also. I've been there many times as well. The diversity is great there, and the shelves make it easier to climb up to get to the other formations.

Share this post


Link to post
Share on other sites
Uncle Siphuncle

hey sward u can see some pics of ms brett and me there right after a good rain in my august 2012 report.

Share this post


Link to post
Share on other sites
squalicorax

3m2iwl.jpg

lW6xAl.jpg

Share this post


Link to post
Share on other sites
erose

The leaves haven't completely dropped have they? These photos must be from last year.

This cut is well known because it exposed almost the entire Richmond group of the Cincinnatian Series. For those not familiar, that is the uppermost of the Upper Ordovician of North America. There is an unconformity that deletes the last stage (Gamaichian?) between the Richmond and overlying Lower Silurian but otherwise it's all there. The classical Cincinnatian units would be Arnheim up thru the Whitewater Formations. I believe the Indiana Geo Survey would call it Dillsboro, Whitewater and Saluda. Almost all of these are there from the very bottom of the cut (Arnheim) up thru the Saluda and Whitewater Formations at the top. The only thing missing is the uppermost Elkhorn/Drakes Fm. It is the soft shales in the Liberty and Waynesville layers that produce the abundance of Flexicalymenes but other trilos can be found throughout in some form.

Share this post


Link to post
Share on other sites
sward

Lotsapets, dan & squali,

That is one massive roadcut! It's obviously a popular spot as well.

Dan, I didn't realize this was the same one as in your report.

I wish we had some like that here in the DFW area.

Thanks for sharing your pics.

Edited by sward

Share this post


Link to post
Share on other sites
IvePieterick

post-18178-0-49166200-1429834528_thumb.jpgMay2014 Trip. We had the whole road cut to ourselvespost-18178-0-31531900-1429834431_thumb.jpgpost-18178-0-49003000-1429834463_thumb.jpg from 9am to until we left because it was getting to dark to keep looking,

Edited by IPieterick

Share this post


Link to post
Share on other sites
ZiggieCie

Whenever we (FCFC) have a Waldron shale-St Paul trip, I always stop there for a good part of the day. I'm from northern Ohio.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Recently Browsing   0 members

    No registered users viewing this page.

×