| The Inyo Craters (North Inyo Crater and South Inyo Crater), and a third crater, Summit Crater, are the largest of more than a dozen 650- to 550-yr-B.P. phreatic craters that lie in a 1-km-square area at the south end of the Inyo Volcanic Chain, on the west side of the Long Valley Caldera in eastern California. The three craters are aligned within a 1-km-long north- south system of fissures and normal faults, and coin- cide in age with aligned magmatic vents farther north in the Inyo Volcanic Chain, suggesting that they were all produced by intrusion of one or more dikes. -- Mastin, 1991 |
