Cascade Canyon, San Antonio Canyon, San Gabriel Mts, San Bernardino Co., California, USA

Approximate elevation of mineralized area is between 4500 and 5000 feet. Geologically, the area consists of metamorphic rock intruded by some granitic masses. Principal stratified layers have an east-west strike and a north dip of about 60 degrees. Beds from north to south consist of quartzite, limestone followed by quartzite, limestone and gneiss. This series is correlated with some paleozoic limestone in the San Bernardino mountains. Mineralization of the area is probably in part due to the intrusion of the igneous mass.

At least 20 minerals can be collected in the Cascade canyon area, among them lazurite, diopside, corundum, "hydrotroilite" and phlogopite. Lapis lazuli occurs in the limestone in small bands from 1/8 inch to six inches wide, sometimes containing pyrite crystals. Corundum has not been found in the canyon proper, but good specimens have been obtained in San Antonio wash. Crystals are from 1/4 inch to one inch in length and are of a pinkish color.

Large variety of metamorphic rocks. Warning: very steep topography subject to landslides. NOTE: This canyon crosses the county lines into Los Angeles County.

References:
Eaton, A. L. 1946. Pomona club collects at mineralized Cascade Canyon. The Desert Magazine, Volume 9 Number 10, August. Desert Press, Inc. El Centro, California, p. 31, 40pp.

Merriam, R. and Laudermilk, J. D. 1936. Two Diopsides from Southern California. The American Mineralogist. 21(11):715-718.