http://oaklandgeology.wordpress.com/2007/10/03/my-secret-chert/ focused on, near and under Oakland, California Sun, 05 May 2013 18:10:05 +0000 hourly 1 http://wordpress.com/ http://oaklandgeology.wordpress.com/2007/10/03/my-secret-chert/#comment-2825 Thu, 26 Apr 2012 03:03:53 +0000 http://oaklandgeology.wordpress.com/2007/10/03/my-secret-chert/#comment-2825 In a cemetery, headstones of local stone may indicate that a family was not affluent enough to buy exotic stone. (I guess if local stone is fabulous [cemeteries in Vermont?], then this rule of thumb does not apply.) This gives me a feeling of having a teasing view into a moment in history of a family, and perhaps of a community.

]]> http://oaklandgeology.wordpress.com/2007/10/03/my-secret-chert/#comment-6 Tue, 09 Oct 2007 03:06:28 +0000 http://oaklandgeology.wordpress.com/2007/10/03/my-secret-chert/#comment-6 Yeah, Oakland’s cherts are good for nothing. They make picturesque knockers. If I ever win the lottery I want to poke around Arkansas and the Texas outliers. But my local cherts are lovely stones. I keep finding them as I dig in the yard and putting them in a pile.

]]> http://oaklandgeology.wordpress.com/2007/10/03/my-secret-chert/#comment-5 Mon, 08 Oct 2007 19:35:58 +0000 http://oaklandgeology.wordpress.com/2007/10/03/my-secret-chert/#comment-5 what’s cool about these cherts is that they are analogous to the cherts of the Ouachita mountains in Arkansas (also the Marathon and Davis complexes in Texas), in that they are a radiolarian cherts tectonically pushed up onto the continent and made famous as sharpening (whet) stones, on the down side, the cherts of the Franciscan complex are often out of a green or blueschist facies and too altered to be abrasive (too recrystalized)

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