Ramo Posted February 11, 2009 Share Posted February 11, 2009 Took a little walk through some shale, and found what I usually find there: lots of concretions and no fossils. Many of the concretions have what look like ammonite shell parts in them, but I've never found much in the shale. I like to look at field photos of different places, and thought some of you might want to see these. For one species to mourn the death of another is a new thing under the sun. -Aldo Leopold Link to comment Share on other sites More sharing options...
Xiphactinus Posted February 11, 2009 Share Posted February 11, 2009 Took a little walk through some shale, and found what I usually find there: lots of concretions and no fossils. Many of the concretions have what look like ammonite shell parts in them, but I've never found much in the shale. I like to look at field photos of different places, and thought some of you might want to see these. you obviously found a sea turtle laying her eggs on the beach! Link to comment Share on other sites More sharing options...
Ramo Posted February 11, 2009 Author Share Posted February 11, 2009 Sorry about the big pictures, but I took the wrong camera, and I'm not smart enough to resize photos. For one species to mourn the death of another is a new thing under the sun. -Aldo Leopold Link to comment Share on other sites More sharing options...
Ramo Posted February 11, 2009 Author Share Posted February 11, 2009 Last photo. This appears to be ammonite shell material to me. What do you think? For one species to mourn the death of another is a new thing under the sun. -Aldo Leopold Link to comment Share on other sites More sharing options...
Guest N.AL.hunter Posted February 12, 2009 Share Posted February 12, 2009 I once found similar stuff that turned out to be shell remains of a large type of oyster called something like Inoceramus. That's the best my memory allows. Link to comment Share on other sites More sharing options...
Guest bmorefossil Posted February 12, 2009 Share Posted February 12, 2009 nice pictures Link to comment Share on other sites More sharing options...
jkfoam Posted February 12, 2009 Share Posted February 12, 2009 Bowkill, I found this definition of a concretion; A concretion is a compact mass of mineral matter, usually spherical or disk-shaped, embedded in a host rock of a different composition. This hard, round mass of sedimentary rock cement is carried into place by ground water. Concretions, the most varied-shaped rocks of the sedimentary world, occur when a considerable amount of cementing material precipitates locally around a nucleus, often organic, such as a leaf, tooth, piece of shell or fossil. (Credit www.desertusa.com with the definition.) A lot of time what happens is that the animal/plant/tooth/etc., that is the center of a concretion, in decomposition releases phosphorous which alters the sedimentary rock chemistry creating the "different composition" of rock in the host rock. Think calcium phosphate in a calcium carbonate world. Umm, this all made a lot more sense to me before I wrote it. JKFoam The Eocene is my favorite Link to comment Share on other sites More sharing options...
MikeD Posted February 13, 2009 Share Posted February 13, 2009 I once found similar stuff that turned out to be shell remains of a large type of oyster called something like Inoceramus. That's the best my memory allows. I don't know why, but for some reason, I was thinking Inoceramus when I looked at that picture. I found one in a concretion. It still has some shell material. Link to comment Share on other sites More sharing options...
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