Rockwood Posted December 12, 2020 Share Posted December 12, 2020 Found this on my last trip to the quarry just northeast of Rockwood. Barring an unexpected snow melt it will be the last for the season at least. It's thought (by me) to represent a marine delta environment. The quarry is likely to be in the Tomhegan formation. Seeing the photos makes me think the shapes are probably all trace fossils. But what would explain all the variation ? Link to comment Share on other sites More sharing options...
ClearLake Posted December 12, 2020 Share Posted December 12, 2020 Interesting looking item. Could it be that it is a "tunnel" that meanders up and down out of the plane of the rock surface (which may just be a break surface, not a depositional surface) so you get different widths? Need to get a 3-D image of it somehow.... Link to comment Share on other sites More sharing options...
Rockwood Posted December 13, 2020 Author Share Posted December 13, 2020 I think it's most likely concretion. It was in debris from a crushing operation, but has a similar look to the layers that contain many oblong concretions the size of a small loaf of bread in a tightly packed pattern.. Link to comment Share on other sites More sharing options...
Rockwood Posted December 13, 2020 Author Share Posted December 13, 2020 Proposed hypothesis: Both highlighted areas are the same burrowing with different preservation. The more mobile, perhaps calcitic, minerals in the fill having been concentrated in the blue areas, and the yellow areas being an iron oxide sand mix. These rocks were baked and shoved around pretty good when the Appalachians were rising so it could well be something that occurred in diagenesis. Link to comment Share on other sites More sharing options...
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