Comments on: What is this? http://antimonite.blogsome.com/2009/01/18/what-is-this/ A blog about geology, geoscience, paleontology and related topics Tue, 01 Dec 2009 02:53:55 +0000 http://wordpress.org/?v=1.5.1-alpha by: personnic http://antimonite.blogsome.com/2009/01/18/what-is-this/#comment-271 Thu, 26 Nov 2009 08:29:22 +0000 http://antimonite.blogsome.com/2009/01/18/what-is-this/#comment-271 http://www.geolsba.dk/echinoids/listeCampan.html http://www.geolsba.dk/echinoids/listeCampan.html

]]> by: mark http://antimonite.blogsome.com/2009/01/18/what-is-this/#comment-226 Fri, 13 Feb 2009 21:25:25 +0000 http://antimonite.blogsome.com/2009/01/18/what-is-this/#comment-226 It looks rather like the various limonite & other concretions/zones that I've seen in the New Jersey & Maryland Coastal Plain Cretaceous units. It looks rather like the various limonite & other concretions/zones that I’ve seen in the New Jersey & Maryland Coastal Plain Cretaceous units.

]]> by: Antimonite http://antimonite.blogsome.com/2009/01/18/what-is-this/#comment-223 Wed, 21 Jan 2009 12:18:33 +0000 http://antimonite.blogsome.com/2009/01/18/what-is-this/#comment-223 Silver Fox: Thanks for your input. Silver Fox: Thanks for your input.

]]> by: Silver Fox http://antimonite.blogsome.com/2009/01/18/what-is-this/#comment-222 Tue, 20 Jan 2009 03:58:52 +0000 http://antimonite.blogsome.com/2009/01/18/what-is-this/#comment-222 I think the heaviness has got to be from the contained iron. The rock reminds me of ferricrete - but that is mostly the color; they do not usually consist of mudstones or siltstones. The only part of it that looks at all fragmental like a ferricret is in the top photo near the top of the rock, where the disruption is probably wavy bedding. But it does make me wonder if Fe-rich solutions from a nearby (or palaeo) spring didn't seep through this mudstone. I can't add much of anything to the origin of the rock other than it looks sedimentary, and is pretty neat looking! Would be great to find The Source! I think the heaviness has got to be from the contained iron. The rock reminds me of ferricrete - but that is mostly the color; they do not usually consist of mudstones or siltstones. The only part of it that looks at all fragmental like a ferricret is in the top photo near the top of the rock, where the disruption is probably wavy bedding. But it does make me wonder if Fe-rich solutions from a nearby (or palaeo) spring didn’t seep through this mudstone. I can’t add much of anything to the origin of the rock other than it looks sedimentary, and is pretty neat looking! Would be great to find The Source!

]]> by: Antimonite http://antimonite.blogsome.com/2009/01/18/what-is-this/#comment-221 Sun, 18 Jan 2009 19:50:20 +0000 http://antimonite.blogsome.com/2009/01/18/what-is-this/#comment-221 Brian: Theres no grading what I can see in the matrix on close inspection. It seems solid. <strong> Ive added two more photos.</strong> Brian: Theres no grading what I can see in the matrix on close inspection. It seems solid. Ive added two more photos.

]]> by: BrianR http://antimonite.blogsome.com/2009/01/18/what-is-this/#comment-220 Sun, 18 Jan 2009 19:13:21 +0000 http://antimonite.blogsome.com/2009/01/18/what-is-this/#comment-220 It has some crude bedding to it ... and there are parts that look like they have a bit of soft-sediment deformation (i.e., bits and blobs of sand stringers 'floating' in the finer-grained matrix). There's no 'smoking gun' diagnostic feature that I can see in these photos to help pinpoint a process interpretation. If one really wanted to know, they could thin section the finer-grained parts to see if there is any very subtle variations in grain size vertically. It would be nice to know if the finer-grained part is homogenous, or does it have any grading? Any very fine structure? At this point I'd be hard-pressed to guess at an origin for this rock ... need to ponder a bit more. Maybe others have offer some good insights. It has some crude bedding to it … and there are parts that look like they have a bit of soft-sediment deformation (i.e., bits and blobs of sand stringers ‘floating’ in the finer-grained matrix).

There’s no ’smoking gun’ diagnostic feature that I can see in these photos to help pinpoint a process interpretation. If one really wanted to know, they could thin section the finer-grained parts to see if there is any very subtle variations in grain size vertically. It would be nice to know if the finer-grained part is homogenous, or does it have any grading? Any very fine structure?

At this point I’d be hard-pressed to guess at an origin for this rock … need to ponder a bit more. Maybe others have offer some good insights.

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