Earth’s Undecaying Monuments: Geological Formation

Yosemite is 114 million years old. It looks good for its age. In geologic time, 114 million years is the blink of an eye, but in human terms Yosemite seems ageless and monolithic. This sense of the eternal is one of Yosemite’s greatest virtues and perhaps its most alluring amenity. In purely scientific terms, however, Yosemite is not timeless, as it has been shaped and reshaped by eons of uplift, scouring, and decomposition. The rock in the region is granitic. The granite structures, called plutons, formed miles deep and rose to the surface during the Late Cretaceous period, after which