Geology Club students under the direction of Dr. Dorais Yosemite National Park.  Starting on the edge of the Tuolomene Intrusion with the May Lake Quartz Diorite and ending in the center of the intrusion with the Johnson Granite Porphry, students were able to get hands-on experience with plutonic rocks.  Everything from contact metamorphism to migmatites and pegmatites to granodiorites loaded with megacrysts of K-spars were seen.  Dr. Dorais used differences and similarities between each formation used as evidence for or against one of two prevailing theories of emplacement for the intrusion.  One theory believes the intrusion formed as one  body of magma cooling from the outside to the inside.  The other theory believes a series of dike-like intrusions formed the Tuolomene intrusion.

      In addition to the igneous side of the park, the glacial history of the park was discussed and used to explain many of the features seen in the park.  Some of the more common glacial features include erratics, glacial polish and a scattering of lakes.  Outside of the park driving toward Bishop, CA the students saw some nice examples of end moraines.