It might be old volcanic ash. We're sitting on top of about 300 feet of the stuff. It like mineral gravy when wet, and like weak concrete when dry.
Phil Hawkins wrote:This stuff isn't rock - it's just really hard packed ... something. It crumbles in the hand easily enough. I will dig some up and take some photos.
I've got no option but to sell you all for scientific experiments. Or a tiny ad:
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