Henry
spending too much on rocks
Member since January 2013
Posts: 452
|
Post by Henry on Apr 2, 2015 19:49:44 GMT -5
Hello everyone. I know I found this at a beach somewhere, but I can't remember the exact location of its recovery. I assume this is brecciated jasper??
|
|
Fossilman
Cave Dweller
Member since January 2009
Posts: 20,681
|
Post by Fossilman on Apr 2, 2015 20:05:24 GMT -5
Looks like jasper..............
|
|
Sabre52
Cave Dweller
Me and my gal, Rosie
Member since August 2005
Posts: 20,456
|
Post by Sabre52 on Apr 2, 2015 21:40:24 GMT -5
On California beaches we would have called that material Franciscan melange. Similar mossy/breccciated jasper ( actually chert as these are marine deposits) comes from all over the Franciscan Formation in California's coast ranges and beyond. Similar material decorates the beaches from Ventura County in Southern Commiefornia to Puget Sound.....Mel
|
|
jamesp
Cave Dweller
Member since October 2012
Posts: 36,155
|
Post by jamesp on Apr 3, 2015 12:38:18 GMT -5
On California beaches we would have called that material Franciscan melange. Similar mossy/breccciated jasper ( actually chert as these are marine deposits) comes from all over the Franciscan Formation in California's coast ranges and beyond. Similar material decorates the beaches from Ventura County in Southern Commiefornia to Puget Sound.....Mel Chert is from marine deposits Mel ? That would make coral chert ? i could look chert up but rather your explanation. I did look it up. It is solidified marl and limestone and a host of other things related to diagenesis(interesting word). diagenesis- the conversion (as by compaction or chemical reaction) of sediment into rock
|
|
|
Post by snowmom on Apr 3, 2015 17:16:33 GMT -5
no idea what it is, but it is beautiful! Lotta depth in that, and sunset colors. LIKE
|
|
|
Post by stephan on Apr 11, 2015 18:03:40 GMT -5
On California beaches we would have called that material Franciscan melange. Similar mossy/breccciated jasper ( actually chert as these are marine deposits) comes from all over the Franciscan Formation in California's coast ranges and beyond. Similar material decorates the beaches from Ventura County in Southern Commiefornia to Puget Sound.....Mel Chert is from marine deposits Mel ? That would make coral chert ? i could look chert up but rather your explanation. I did look it up. It is solidified marl and limestone and a host of other things related to diagenesis(interesting word). diagenesis- the conversion (as by compaction or chemical reaction) of sediment into rock The chert comes from radiolarians -- protozoa with mineral exoskeletons. Much of our jasper is created that way. After becoming terrestrial, it is further silicified by silica-bearing water. www.nps.gov/goga/learn/education/upload/Rock%20information%20cards%20TT_small.pdf
|
|
jamesp
Cave Dweller
Member since October 2012
Posts: 36,155
|
Post by jamesp on Apr 11, 2015 18:25:50 GMT -5
Thanks stephan. Similar to our chert in S Georgia and Florida. We have no lava flows, so all silicifications are related to settlement, diatoms, bryozoans, algae and the like. Same silicification process, clay did wash down from Appalachia and mixed with the marine life and minerals from limestone via silica bearing water to make some fine colors too. Like the article mentioned, these cherts are very hard and ring like glass. Acting as if they are Mohs 7.5. A batch of mostly coral collected from a small boat for a half mile section of the Withlacoochee River near Valdosta Georgia. Highly replaced, but fingerprint of coral still in every bit of it in the form of microscopic capillaries. Some of the corals are hundreds of pounds. They are not protected here, actually considered a nuisance in the form of prohibiting boat traffic. The river exposes them; they occur over a large area at 80 to 100 feet above sea level. oops, forgot the flickr link www.flickr.com/photos/67205364@N06/sets/72157635757224243
|
|