Lapidaryforum.net
Let's Rock => Mineral Specimens => Topic started by: Rustycat on October 07, 2018, 09:36:53 AM
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Thought I'd ask the good folks for their opinion of the following two cobbles I found on the beach. So, thanks in advance!
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The first is an iron stained porphory, possibly diabase.The second looks like a chert that was being down metamorphosed when i8t stopped changing. The inclusions give it away .
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lithic,
I had hoped you would reply, so thank you. I'm trying to understand your comment, and in my effort to do so, I went to https://www.tulane.edu/~sanelson/eens212/typesmetamorph.htm
Which to the lay-student's eye seems to be offering a well-developed background to understanding your reply.
BTW, the tulane link will probably take me several weeks of daily reading for me fully wrap my head around.
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The problem with geology is that the pictures never match the reality of the areas outside the area the pictures were taken in. Very frustrating.I got around this problem by getting local field guides off the internet and going to the spots and seeing our local version of the rock type.Then I read most of the masters degrees in geology from WWU and many of the phd dissertations from the UW and went in the field to see the samples.Not much stuff is on the net now. Stuff that used to be free you now have to pay for but let me think about it.