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Jacob Clarke's avatar

Very cool! Phreatic eruptions are spectacular explosions and make for great YouTube videos. I remember seeing some thin sections from phreatic explosions in a few of my courses, and as much as I’m not a petrologist, they were pretty fascinating.

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Luther Lemke's avatar

Good award for an excellent communicator

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Mike Reinke's avatar

Cool, Richard. I knew about the plate moving over the hotspot, not the hotspot moving, but I did not know that water could make basalts lighter colored, at least, not quickly! (But at those temps..

yeah probably)

Last week I got to visit Mt. Taal, south of Manila. Just rode on the road near the lake, but picked up some volcanic samples for my microscope. A week later it had a 5 or 10 minute ejection of steam. Lots of 10+ story condos/apartments, and a few Starbucks around the rim. Hmmmmmm....

Palawan where I live is not on the ring of fire like they are. I'm too far west.

So they say...

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Richard I Gibson's avatar

Since I haven't seen the rocks from the islet in person, I'm not positive, but I think it is so altered that it would not be considered to be lighter colored basalt, not basalt at all. Altered basaltic ash perhaps. The minerals would be so hydrated that no mineralogical analysis, and probably no chemical analysis, would come close to basalt. I think. Probably andesitic or even rhyolitic in composition now, with the ferromags going away during the alteration to feldspars etc. But I don't know for sure.

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Mike Reinke's avatar

Makes sense.

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Bob Chesson's avatar

Interesting "tease" so I'll bite. What is your involvement with the American Urological Association and connection with kidney stones?

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Richard I Gibson's avatar

None today, but 50+ years ago I analyzed the mineralogy of about 20,000 of them. http://www.gravmag.com/kstones.shtml

https://richardigibson.substack.com/p/kidney-stone-mineralogy

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