Douglas B Hill Posted December 23, 2018 Share Posted December 23, 2018 Question for the group: is it common for a clam shell to pyritize in contact with a clay? This was from Edisto Beach SC. They were buried in mud to where they are not pyrite. I am assuming the clay is heavy in iron sulfide. Douglas. 5 Link to comment Share on other sites More sharing options...
DPS Ammonite Posted December 23, 2018 Share Posted December 23, 2018 The pyrite was protected by the clay from oxygen and water and erosion. Oxygen and water will “rust” the pyrite turning it into iron hydroxides that are easily eroded away. 1 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...
FranzBernhard Posted December 23, 2018 Share Posted December 23, 2018 These are lovely, thanks for sharing! I think, @Max-fossils will also like them. And they seem to be all bi-valve. Is the pyrite only a surface coating? Is the white stuff still shell material? And is the gloss natural or have you polished them? Franz Bernhard 2 Link to comment Share on other sites More sharing options...
doushantuo Posted December 23, 2018 Share Posted December 23, 2018 Pyrite formation is controlled by several factors. The necessary sulfur ions might be present in porewater,and/or in the sediment itself.The amount of sulfur varies with depth. edit: depth below the sediment/water interface ,that is.Ecology plays a role as well. Would be nice to know if these bivalves are(obligatory) infaunal,and if so,what would be the average living depth in the sediment Interesting find,Douglas,thx for showing us edited by user,24-12-2018,spelling correction 4 Link to comment Share on other sites More sharing options...
Tidgy's Dad Posted December 23, 2018 Share Posted December 23, 2018 Lovely bivalves! 1 Life's Good! Tortoise Friend. Link to comment Share on other sites More sharing options...
RJB Posted December 23, 2018 Share Posted December 23, 2018 Very nice. RB 1 Link to comment Share on other sites More sharing options...
Max-fossils Posted December 24, 2018 Share Posted December 24, 2018 Wow, gorgeous shells!!! I love how only half of them are pyritized. Hard to guess without seeing the hinge, but I believe these shells would be Mercenaria sp. Awesome finds! Max Max Derème "I feel an echo of the lightning each time I find a fossil. [...] That is why I am a hunter: to feel that bolt of lightning every day." - Mary Anning >< Remarkable Creatures, Tracy Chevalier Instagram: @world_of_fossils Link to comment Share on other sites More sharing options...
Jeffrey P Posted December 25, 2018 Share Posted December 25, 2018 Those are indeed quite stunning. Lovely find. Thanks for sharing them. Link to comment Share on other sites More sharing options...
Ludwigia Posted December 25, 2018 Share Posted December 25, 2018 Yes, it is a common occurrence in particular clay deposits where anaerobic circumstances prevailed that shell substance can be transformed into pyrite. 1 Greetings from the Lake of Constance. Roger http://www.steinkern.de/ Link to comment Share on other sites More sharing options...
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