Structure and origins of glacial polish on Yosemite’s rocks
The glaciers that carved Yosemite Valley left highly polished surfaces on many of the region’s rock formations. These smooth, shiny surfaces, known as glacial polish, are common in the Sierra Nevada and other glaciated landscapes. Geologists have now taken a close look at the structure and chemistry of glacial polish and found that it consists of a thin coating smeared onto the rock as the glacier moved over it. …read more