Karl Strauss Brewery Migmatite and Gneiss

The stereotypical image of a geologist often brings a few things to mind, but one of the most commonly perceived notions is that geologists like to drink, especially beer.  When you stumble upon a location that combines geologists love of alcohol and rocks together you get their equivalent of Disneyland.  At the Karl Strauss Brewing Company located in Sorrento Valley, California you have the chance to wander around and view a beautiful array of migmatite and gneiss boulders (high-grade metamoprhic rocks) that display all sorts of features before and after you have a pint of beer.

High-grade metamorphic rock with unique features including faults on the left and right side of the block, unique vein like red garnet crystal arrangement, a Z-fold in the middle, and a boudin just to the right of the Z-fold.

This boulder appears to be foliated with some sense of shearing happening.  Although it's hard to interpret, it's possible we can see ptygmatic folds which are common in migmatites.

This boulder is a little more weathered in appearance compared to the other ones in the parking lot, but still displays some great features.  These include a large assortment of faults, dikes and dikelets, and garnets which can be seen on the bottom-right of the boulder as brown dots.

Another migmatite boulder with some beautiful foliation.

Finally we get to this giant boulder that displays many of the features that I have pointed out in the pictures above it, see if you can find some of the features for yourself!