Piedras_de_Tejas Posted June 2, 2014 Share Posted June 2, 2014 (edited) Does anyone know of a specific name for flint or chert nodules containing quartz-replaced fossils? Also, do these form in a particular formation or did they develop in several in the presence of dissolved quartz? i have found these in many areas around san antonio and they're my favorite to encounter. The first pic resembles tube worms to me and i have no clue what the fossils are in the second two images, but the one that appears as dozens of adjacent, long, parallel columns comes up often in my area. Edited June 2, 2014 by Piedras_de_Tejas Cameron C. "The important thing is to not stop questioning. Curiosity has its own reason for existing" - Albert Einstein Link to comment Share on other sites More sharing options...
Piedras_de_Tejas Posted June 2, 2014 Author Share Posted June 2, 2014 (edited) Here is an unknown quartz-lined shell (and some impressions) in chert matrix, one of my favorite specimens. Edited June 2, 2014 by Piedras_de_Tejas Cameron C. "The important thing is to not stop questioning. Curiosity has its own reason for existing" - Albert Einstein Link to comment Share on other sites More sharing options...
RyanNREMTP Posted June 2, 2014 Share Posted June 2, 2014 Looks like hash plates which is a term for a piece of matrix containing a mixture of fossils. I see what could some nautiloids and in the second picture could be an imprint from a horn coral. Nice finds. Link to comment Share on other sites More sharing options...
JohnJ Posted June 2, 2014 Share Posted June 2, 2014 Rudists and gastropods are common in the chert nodules in your area. The human mind has the ability to believe anything is true. - JJ Link to comment Share on other sites More sharing options...
Uncle Siphuncle Posted June 2, 2014 Share Posted June 2, 2014 Agreed. Looks like you wandered into the Edwards Formation. It outcrops near the Del Rio fm stuff you mentioned previously. FYI, Edwards is the same fm that outcrops in the road cuts along 1604 near 281 on the north side. Grüße, Daniel A. Wöhr aus Südtexas "To the motivated go the spoils." Link to comment Share on other sites More sharing options...
Piedras_de_Tejas Posted June 4, 2014 Author Share Posted June 4, 2014 Thanks guys. I think ive seen what you're talking about dan, a few hundred feet from my del rio site, but it was mostly flint and chert nodules far too big to carry and no sign of visible fossils... Most of this stuff comes dissociated in the creek bed by my house so i just collect them when the fossil concentration is high or its an interesting piece. Cameron C. "The important thing is to not stop questioning. Curiosity has its own reason for existing" - Albert Einstein Link to comment Share on other sites More sharing options...
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