274 The American Geologist. May, 1902. 
The special purpose of this paper is to show some of the in- 
teresting problems presented by the older crystalline rocks of 
southern California and to make a beginning in their classi- 
fication, although the latter will be only tentative. During 
the past winter the writer had the opportunity of examining 
in a reconnaissance manner, the Fraser Mountain and Sierra 
Pelona regions, and portions of the Tehachapai, Sierra Madre 
and San Bernardino ranges, together with quite an extended 
section of Mohave desert, all comprised in the counties of 
Los Angeles, Ventura, Kern and San Bernardino. A special 
search was instituted for an equivalent of the Klamath schist 
series and the reader may judge from the following pages 
what success attended this effort. 
Structurally, that portion of southern California which lies 
between Mohave desert and the sea, is a succession of roughly 
rectangular orographic blocks bounded by faults. Some of 
these blocks have been greatly elevated and the soft sediments 
eroded from off the crystalline complex, while others have 
been profoundly depressed and in them the older rocks are 
buried under a vast thickness of Cretaceous and Tertiary sed- 
iments. 
The different members of the crystalline rocks discriminat- 
ed will be discussed under the following headings: 
1. The Pelona Schist Series. 
2. The Gneiss Series. 
3. The Rocks of Fraser Mountain and Vicinity. 
4. The Mesozoic Granites. 
5. The Ravenna Plutonic Series. 
6. The Gneiss near Barstow. 
7. The Quartzyte-Limestone Series of Oro Grande. 
8. The Schists in Cajon Pass. 
Tue Petona Scuist SErRIes. 
The eastern portion of the valley of the Santa Clara river, 
in Los Angeles county, is bounded on the north by a prominent 
ridge, known as the Sierra Pelona. It reaches an altitude of 
5000 feet and has a comparatively even crest-line and narrow 
but rounded summit. It is a single narrow fault-block, elevat- 
ed at the close of the Pliocene period and tilted steeply to the 
south. The entire ridge from Deadman’s canon on the west 
