Dating topography of the sierra nevada
These areas include Yosemite, Sequoia, and Kings Canyon National Parks; and Devils Postpile National Monument.The character of the range is shaped by its geology and ecology. (million years) ago, and erosion by glaciers exposed the granite and formed the light-colored mountains and cliffs that make up the range.Notable Sierra features include Lake Tahoe, the largest alpine lake in North America; Mount Whitney at 14,505 ft (4,421 m), the highest point in the contiguous United States; and Yosemite Valley, sculpted by glaciers out of one-hundred-million-year-old granite.The Sierra is home to three national parks, twenty wilderness areas, and two national monuments.Variations in topography through time have profound implications for processes as obvious as erosion and sedimentation and as diverse as global climate and the formation of mineral deposits.The interplay between topography and tectonics is exemplified by the evolution of topography of the Sierra Nevada and Great Basin (United States), and by geologists' interpretation of that evolution.
The Sierra runs 400 miles (640 km) north-to-south, and is approximately 70 miles (110 km) across east-to-west.These Great Valley Group strata crop out in a homocline along the western margin of California’s Central Valley, and are in fault contact with the Franciscan accretionary complex (Dickinson This paper focuses on samples of the Great Valley Group collected in and around Joaquin Ridge near Coalinga (Figure 1).These sedimentary rocks contain geochronological and petrographic information about the evolution of their source region, the Mesozoic Sierra Nevada magmatic arc.Times of glacial advance in the Sierra Nevada may be connected to the melting history of the ice sheets, and to Heinrich events, by expansion and contraction of sea ice in the southern North Atlantic. Geological Society of America Bulletin 110, 1318-1332.