Thursday, October 15, 2015
A Series of Fortunate Events: Fall in Yosemite National Park
The Mariposa Slate is a deposit that formed on the bottom of a deep sea off the coast of California in Jurassic time. The shoreline lay east of where it is today, and the Sierra Nevada was a different place: a series of active volcanoes led to a coastal forest. Dinosaurs, pterosaurs, and primitive mammals roamed the forests and floodplains. In the sea, large swimming reptiles including plesiosaurs and ichthyosaurs were found. The Mariposa is somewhat less altered than many other rocks of the metamorphic belt, and because of this, a few fossils have been found which enabled geologist to figure out the age of the rocks. This was an important step in unraveling the complex geologic history of the region.
Our path was not the straightest route. Instead of following Highway 140 directly into Yosemite, we turned south at Mariposa and followed Highway 49 to the town of Oakhurst. We were having a look at the largest living things in existence, as well one of the greatest mineral collections in the state. More next time!