Asineops in almost black shale? Which quarry could it be?

[oilshale]

This is not about the identification of a fossil (it's an Asineopps squamifrons) but about the identification of a quarry unknown to me.
I received two Asineops squamifrons from a friend, unfortunately without a location (he received it as a gift, the fish themselves are not very well prepped). What irritates me is that the rock doesn't look like Green River Formation at all - at least not like the rocks I have encountered in the quarries around Kemmerer. The rock is relatively fine-grained and very dark, almost black, and probably has a high organic content. The two Asineops in it also look almost charred.
I've only dug once at Lake Gosiute sites (Currant Creek Ranch), but I don't know of any dark rock like this from there either. And it doesn't look like Farson either.
I am at a bit of a loss. Can anyone give me a hint as to where this slab could be from?

[rfarrar]

There are exposures with this lithology in Sweetwater County, WY near the Flaming Gorge reservoir and environs. Fish found there are Asineops sp., Amyzon sp., and Astephus sp.

[jpc]

I have not seen this lithology, but I have found Asineops in the Green River Lake Uinta beds in Sweetwater County, as rfarrar mentions.   

[oilshale]

On 2/6/2024 at 2:54 AM, rfarrar said:

There are exposures with this lithology in Sweetwater County, WY near the Flaming Gorge reservoir and environs. Fish found there are Asineops sp., Amyzon sp., and Astephus sp.

 

On 2/6/2024 at 5:58 AM, jpc said:

I have not seen this lithology, but I have found Asineops in the Green River Lake Uinta beds in Sweetwater County, as rfarrar mentions.   

Thanks a lot for the hints. I did some searching in the literature and came across the Black Shale Member of the Green River Formation of Lake Uinta in Utah.  So Lake Uinta seems likely - unfortunately, it will not be possible to narrow down the location any further,

[rfarrar]

Take a look at the G-2 sites in Grande's Bulletin 63 Paleontology of the Green River Formation. We have several fishes from the Sweetwater County Lake Gosiute deposits in a black to dark gray fissile shale. We found some of these species in readcuts south of Little America back in the late 1970's.

[oilshale]

Great - thank you very much. This could even fit well together in time. My friend said he probably got it in the late 70s / early 80s from a fossil dealer in Frankfurt / Germany (Jürgen A. Schmidt)

[rfarrar]

Henzel from Celle could have also had some material from these localities a few years after Schmidt. He was always trying to provide unusual and high quality specimens to the museums.