Saturday, July 9, 2011

Fanglomerates - deceptive but not if you take a closer look

The new word I learned today is Fanglomerate. I think it's quite strange where I came across it. I'm currently reading a book about stromatolites (since after all my thesis work is about them), and one of the chapter's is explaining the physicochemobiogeo (hope that's a word! should i add nano?? ;D) changes that had occurred to the 3rd rock from the sun that caused the right environment for these organo-sedimentary structures to form. Suddenly the author decides to throw out the word fanglomerates as part of continental deposits created around 2.6-2.0 by. So ofcourse my 1st reaction is that it's a conglomerate.....but why term fanglomerate? So unlike flakestone, there's plenty of descriptions and definitions about fanglomerates. Made me feel stupid of course! Didn't see the break down of the word to fanglomerate.....

So to sum up what i've read about fanglomerates: these are conglomerates (my gut instinct has never failed me!) but those that are usually coalesced to form an alluvial fan. Thus they would mostly be found at mountain foothills where the mostly coarse (large) material eroded off the mountains mixed with finer material to form the fan at it's base or into a mountain lake and then was cemented and solidified into a rock.

Here's the American Geologica Institute definition:

So my question is, can a delta or deep water alluvial fan be called a fanglomerate too?

And I have to give credit to a geologist Callan Bentley where he has a good picture of a fanglomerate that is found at a contact metamorphism near the Sierra Nevadas! Check out his blog & pictures:

Now i understand why my professor goes off on a tangent every time she lectures! I went off on the biggest tangent yet enough to blog, whilst reading about stromatolites! :( Back to work!

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