Rocky Stoner Posted July 4, 2017 Share Posted July 4, 2017 Hi folks. Several years ago while digging shale with an excavator for road repair, we hit what appears (now, with forum learning) to be a concretion, typical oval/oblong shape about 5' long. We had to dig around it as it was too hard to even scratch with the machine. Over the years it has degraded to where it is quite fractured from the weathering and is easily broken up. The pic is a portion of a "ball" of densely packed fossils that was near the center of the concretion. Could this cluster have been the nucleus ?, or could it have just gotten caught up in the formation ? This is about 3 miles from my digs at home and is a much harder, blue/black shale that was at a depth of about 8'. Nice and clean ... no scrubbing necessary. Thanks Link to comment Share on other sites More sharing options...
Darktooth Posted July 4, 2017 Share Posted July 4, 2017 Without seeing the object before it weathered down, this may have just been a chunk of real hard matrix, not necessarily a concretion or nodule. Though it is common for them to form around a fossil "nucleus" they usually form around a isolated fossil. Not an entire cluster. At many of the sites I collect at, certain layers can be extremely hard but after awhile out in the elements they break down nicely. Sometimes in a matter of days. That material I get from Deep Springs only needs a few days of sitting in my garden in the hot sun. Either way it is an interesting find. 1 I like Trilo-butts and I cannot lie. Link to comment Share on other sites More sharing options...
ynot Posted July 4, 2017 Share Posted July 4, 2017 It is common in some formations to have "lenses" of fossils that were accumulated shells in a depression in the sea floor. This lens can have a high concentration of shell while the area around it can be barren of fossils. It is hard to determine if the iron came from the soil or the organic material, but it does often form concretions around organic remains. Darwin said: " Man sprang from monkeys." Will Rogers said: " Some of them didn't spring far enough." My Fossil collection - My Mineral collection My favorite thread on TFF. Link to comment Share on other sites More sharing options...
Rocky Stoner Posted July 4, 2017 Author Share Posted July 4, 2017 Thanks guys. Darktooth, I think you described this precisely. This was not a concretion. Although it initially resembled one, it broke down into very small layered pieces, nothing like the true concretions that I found in the same are just a few feet away which have been exposed for the same duration but are very hard to crack and have no layering. Like this pic ... Thanks again gents. Link to comment Share on other sites More sharing options...
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