- Joined
- Mar 7, 2009
- Messages
- 542
Thanks Kevin! I am slow.
Unfortunately not one found by me D and yes deliberately etched, probably in HCl. Round here there are silicified corals in Paleogene limestones that etch out nicely in white vinegar. A detail of one of these is attached.
Apparently silicifed fossils are far more abundant in the Palaeozoic than in the post-Permian (related to changes in abundance of siliceous sponges). The Permian of the Glass Mountains, Texas is a very famous example.
This has some interesting details on the mechanism of and controls on silicification of fossils.
Unfortunately not one found by me D and yes deliberately etched, probably in HCl. Round here there are silicified corals in Paleogene limestones that etch out nicely in white vinegar. A detail of one of these is attached.
Apparently silicifed fossils are far more abundant in the Palaeozoic than in the post-Permian (related to changes in abundance of siliceous sponges). The Permian of the Glass Mountains, Texas is a very famous example.
This has some interesting details on the mechanism of and controls on silicification of fossils.