Sierra Nevada 04: Logs and Lake, Hoover Wilderness

Image Commentary

The Sierra Mountains of Eastern California are comprised of rocks that together tell a turbulent tale of immense geological processes deep within the Earth's crust. Sixty five million years ago, this was the site of crustal subduction where a heavy, sinking, oceanic crustal "plate" was once being over-ridden by a lighter continental plate. The interface between the two was a hot and disharmonious place where molten, liquid rock injected and invaded the solid strata of the overlying continental plate, causing great plume-like intrusions, numerous dykes and sills, and rich mineral associations. Over many eons, this imbroglio slowly cooled and congealed, at first deep below the surface, but gradually exposed as weathering processes scoured deeper and deeper. Today where this once tumultuous interference is now exposed, we see mountains of many colors that record both the intruding granite magmas, and the multicolored "country rocks". We call these batholiths and roof pendants, and they are the sites of many great and valuable mineral deposits, including gold, silver, copper, lead and many more exotic minerals.