Slabs of ancient tectonic plate still lodged under California
Monday, March 18, 2013 - 17:30
in Earth & Climate
The Isabella anomaly -- the seismic signal of a large mass of cool, dehydrated material about 100 kilometers beneath central California -- is in fact a surviving slab of the Farallon oceanic plate, according to new research. Most of the Farallon plate was driven deep into the Earth's mantle as the Pacific and North American plates began converging around 100 million years, eventually coming together to form the San Andreas fault.