a Super 8, after visiting Shore Acres and Sunset Bay State Parks on March 8, 2012. At a rough visual estimate, and taking the pinkish/buff minerals as alkali feldspar, the whiter/creamy minerals as plagioclase, and the darker grey as quartz, I'm putting the akali feldspar at ~25%, plag at ~40%, quartz at ~30%, with the remaining 5% or less as mafic minerals, probably mostly amphibole and magnetite. According to this QAP diagram (scroll down a bit past the rock photos and following block of text), that makes it a true granite, assuming I've got the mode more or less right. The interesting things here are that, first, the rock appears to have a distinct metamorphic fabric, with the mineral grains flattened roughly parallel to horizontal in this view, and second, there is a distinct right-lateral shear zone running vertically on the right side. I appreciate when nice rocks are used in the design of a living space, even if I only live there overnight.
Photo unmodified. March 9, 2012. FlashEarth location.
Is This Your Hat?
2 years ago