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zone that extends for 80 miles along the San Andreas fault and is within

20 miles of the fault zone.

The Rand schist (Hulin, 1925, pp. 23-31; Simpson, 1934,

pp. 380-381), identical in lithology and structure and thus believed to

be a correlative of the Pelona schist, is exposed near Randsburg, 60

miles northeast of the Sierra Pelona. Miller (1946, p. 528) and Hill

and Dibblee (1953, pp. 450-451) have suggested that the Orocopia schist,

which is exposed in the vicinity of the Salton Sea 160 miles southeast of

the Sierra Pelona, is a correlative of the Pelona schist. Schists that

are texturally and mineralogically similar to the Pelona schist form

the 'basement" rock of the Old Puente oil field, and have led Schoellhamer
1

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and Woodford (1951, map sheet) to suggest that the Catalina and Pelona
schists may grade into one another, and may be of the same age,

possible pre-Cambrian' 1 • The present incomplete state of knowledge

of the metamorphic terranes of southern California does not permit a

more definitive statement.

Hershey (1902a, pp. 274-277) named and briefly described

the Pelona schist on the basis of a traverse across the Sierra Pelona.

Thirty years later, Webb (1932, pp. 12-28) described the geology of an

area along the southeast flank of the Sierra Pelona. Clements (1932,

pp. 16-20) studied the western tip of the Sierra Pelona during the course

of his investigations in the southeastern Tejon quadrangle. Simpson's

study ( 1934, pp. 378- 381) of the Elizabeth Lake quadrangle includes

the outcrops of Pelona schist on Portal Ridge and most of the Sierra