Saturday, January 11, 2014

Geo 730: Jan. 11, Day 376: A Chip Off the Old Block

Another shot from Dana, this shows a small hand sample across the rim of a dike and the surrounding diabase. I can't tell with any certainty whether this is older dike material, or unusually fine magma chamber gabbro, though I'd lean toward the former. As we saw in Thursday's photo, there is a lot of variation in grain size, even within a single dike, and in yesterday's photo, the cumulate gabbro tends to be pretty coarse-grained (if that's what we were actually seeing in that photo).

Photo by Dana Hunter, unmodified. May 8, 2013. FlashEarth Location actually kinda looks like it might be right. Indexed

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