Becky Benfer Posted June 24, 2018 Share Posted June 24, 2018 I believe the same “super silver” material (that I found from another trip here)may have once been present in the round areas on this piece of slate. But not sure as I didn’t see any anywhere this time. Do you have any ideas what may have caused them? I think the rock is slate. Right? It was found near a river in Ohio. Thanks! Link to comment Share on other sites More sharing options...
Becky Benfer Posted June 24, 2018 Author Share Posted June 24, 2018 Back Link to comment Share on other sites More sharing options...
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Innocentx Posted June 24, 2018 Share Posted June 24, 2018 These may be shell impressions but they lack details and really look more like natural fractures of this rock. "Journey through a universe ablaze with changes" Phil Ochs Link to comment Share on other sites More sharing options...
Rockwood Posted June 24, 2018 Share Posted June 24, 2018 I think it is most likely concretion. Wait until someone familiar with the formation weighs in though. Concretions often preserve fossils that are not obvious to the untrained eye. Link to comment Share on other sites More sharing options...
Bullsnake Posted June 24, 2018 Share Posted June 24, 2018 Interesting, and neat piece! It looks to me like shale, or maybe shaley limestone. The circles could be poorly preserved fossils, as noted by Innocentx, or perhaps burrows. Provenance (where it was found) could help someone familiar with the geology of the area identify it. I'd be tempted to split it along the fracture (red arrow) to see if anything is in there! Steve Link to comment Share on other sites More sharing options...
Becky Benfer Posted June 24, 2018 Author Share Posted June 24, 2018 Thank you! I found it in Ohio- almost centrally located but a tad bit NE I the Huron River. Hope this helps. There are places where the “floor” of the river is covered with huge pieces of what I’m calling slate . It may be shale as mentioned above. I really do not know the difference. Link to comment Share on other sites More sharing options...
Rockwood Posted June 24, 2018 Share Posted June 24, 2018 15 minutes ago, Becky Benfer said: It may be shale as mentioned above. I really do not know the difference. My understanding is that slate is just shale that was deposited in exceptionally flat bedding plains. I think the best you could do on this is for it to be an inclusion in slate. Link to comment Share on other sites More sharing options...
DPS Ammonite Posted June 24, 2018 Share Posted June 24, 2018 3 minutes ago, Rockwood said: My understanding is that slate is just shale that was deposited in exceptionally flat bedding plains. Slate is a metamorphic rock which is made when heat and pressure change the minerals in shale. The clay minerals in shale metamorphose into micas that form planes. The planes or foliation do not always coincide with the original bedded but are perpendicular to the greatest stress. Fossils in slate are really rare since they are almost always destroyed. My goal is to leave no stone or fossil unturned. See my Arizona Paleontology Guide link The best single resource for Arizona paleontology anywhere. Link to comment Share on other sites More sharing options...
Rockwood Posted June 24, 2018 Share Posted June 24, 2018 7 minutes ago, DPS Ammonite said: Slate is a metamorphic rock which is made when heat and pressure change the minerals in shale. The clay minerals in shale metamorphose into micas that form planes. The planes or foliation do not always coincide with the original bedded but are perpendicular to the greatest stress. Fossils in slate are really rare since they are almost always destroyed. I see. My understanding has a local twist in that all the shale in Maine is slightly metamorphosed. Perhaps bedding plays a greater role locally ? I never new my maternal grandfather because he died of silicosis from working in a slate quarry when I was very young. Link to comment Share on other sites More sharing options...
Pumpkinhead Posted June 24, 2018 Share Posted June 24, 2018 Here's an example of a slate: In this case original bedding is preserved but if you look closely there are lines of foliation at an oblique angle to the bedding at about the same angle as this slash: / Slate will often have a parting induced by pressure exerted on it during deformation. This is called fissility. In some cases, a given slate may have undergone multiple deformational episodes in which case there will be more than one group of parallel lines of foliation such as the one in the image above. Slate may also appear slightly more lustrous than shale due to the presence of micas which DPS ammonite previously mentioned. These are some good ways to distinguish between slate and shale visually as well as what DPS ammonite mentioned with regards to fossil content Link to comment Share on other sites More sharing options...
Rockwood Posted June 24, 2018 Share Posted June 24, 2018 Grampy would have called it slate if they could make electrical panels and pool tables out of it. Link to comment Share on other sites More sharing options...
abyssunder Posted June 24, 2018 Share Posted June 24, 2018 Don't know what you mean saying "super silver", but If I can guess, your specimen might be in the realm of desiccation or cooling pattern, which may be not far from the counter septarian structures. Of course, this is just a supposition, in case if it's not something like Stigmaria. " We are not separate and independent entities, but like links in a chain, and we could not by any means be what we are without those who went before us and showed us the way. " Thomas Mann My Library Link to comment Share on other sites More sharing options...
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