Wanted: Pictures of worn down in-situ fossils

[gigantoraptor]

Hello all

 

I have an unusual request for you all. I would like to see the results of prolonged weathering of in-situ fossils. So I was wondering if someone here has ever seen a fossil in-situ they didn't think was possible to extract, and a fossil of the same, or similar piece worn away sometime later. Ideally with an estimated time for the fossil to wear down. The turtles of the White River formation are the first thing that come to mind about this, but trackways should be possible too. The more impressive the fossils is,  the better. Additionally, a picture of a specific natural spot (clif, badlands...) with a picture of the same spot over a period of time, to see how quick the environment can change the view of the landscape.

 

I'm aware it's an unusual request, but this isn't something you can easily find on the internet.

 

Hope I made some sense throughout this post.

Thanks in advance.

[Thomas.Dodson]

I've seen some pretty interesting examples of what you've requested but I'm not sure I currently have any pictures. I once extracted a weird looking piece of Eutaw Formation "matrix" in Georgia once that was so weathered I thought it was geologic. I only recently discovered that it was actually another Placenticeras benningi that was so worn I didn't recognize it. The stuff from the site is all exposed in a riffle so the stuff wears down quickly.

 

There are lots of examples of massive beds of Ophiomorpha trace fossils in the Fox Hills Formation I frequent here in North Dakota in various states of exposure and thus wear. When the snow is gone and I'm out again I'll see if I can remember to grab some pictures for you. For pictures of the same spot over a period of time I can only think of site pictures in old publications where the site still exists. I can think of a few that I might have modern pictures of although the publication photos probably won't be that good. I'll take a look when I get a chance.

[Thomas.Dodson]

For your additional request I did find these pictures I have of an exposure of the Fox Hills Formation. Depending on opinions this represents the contact between the lowest portion of the Fox Hills Formation in North Dakota (defined as Timber Lake Member by that author) and the Elk Butte Member of the Pierre or the contact between the Trail City Member and the Pierre Shale at the very base of the outcrop. I follow the Trail City opinion based on what I've seen but I suppose that's besides the point for what you're looking for. At any rate, it illustrates changes in outcrops over time pretty well.

 

In paper published in 1967. The arrows represent the same feature of the cliff.

2018.

Side view showing slumping.

[Thomas.Dodson]

Here's another I remembered, an exposure of the Pierre Shale in Ransom County, North Dakota (it straddles the county border with Barnes, ignore the subtitle, it is Ransom). I've read that this outcrop, one of the most complete sections in this portion of the state, produced good ammonites and baculites. Unfortunately, this was covered in soil, erosion netting, and planted in the past 5 years, right after I learned about its fossil potential so I never got to hunt it. Funny enough, I used to take school groups into the nearby stream for aquatic research outreach so I passed this roadcut several times, I just never tried to hunt it until it was too late. If you want another after pic of how humans destroyed it I can get you that too. 

 

1965.

 

2012.

[gigantoraptor]

On 23-1-2021 at 4:17 AM, Thomas.Dodson said:

Here's another I remembered, an exposure of the Pierre Shale in Ransom County, North Dakota (it straddles the county border with Barnes, ignore the subtitle, it is Ransom). I've read that this outcrop, one of the most complete sections in this portion of the state, produced good ammonites and baculites. Unfortunately, this was covered in soil, erosion netting, and planted in the past 5 years, right after I learned about its fossil potential so I never got to hunt it. Funny enough, I used to take school groups into the nearby stream for aquatic research outreach so I passed this roadcut several times, I just never tried to hunt it until it was too late. If you want another after pic of how humans destroyed it I can get you that too. 

Thanks for both the advise, as well as for the given examples. They work pretty good for what I want. Still looking for some pictures of fossils, but that's already a great start.