60 REVIEWS 



gradually increases as it advances northward to a maximum o{ about twelve miles 

 west of Scott Valley. Southward from the Trinity River, the pre-Paleozoic area is 

 occupied chiefly by the Abrams mica-schist, the hornblende-schist being confined to 

 narrow strips, but northward from the Trinity River the hornblende-schist spreads 

 out and finally nearly excludes the mica schist as in the valley of the South Fork of 

 the Salmon River. Still farther north, in the mountains west of Scott Valley, the 

 mica-schist has again asserted its supremacy. 



O H. Hershey, " Some Crystalline Rocks of Southern California." Ameri- 

 can Geologist, Vol. XXIX (1902), pp. 273-go, 



Hershey describes the results of a brief examination of 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 of 

 California. The crystalline rocks are discriminated under the following heads: (i) 

 "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 Quartz- 

 ite-Limestone Series of Oro Grande ; " ( 8 ) " The Schists in Cajon Pass. " 



The Pelona schist series and the adjacent gneisses, the rocks of FVaser Mount- 

 ain and vicinity, and the gneiss near Barstow are tentatively correlated with the 

 Abrams schist of the Klamath region in a general way, and are considered pre- 

 Paleozoic, perhaps in part Archsean and in part Algonkian. 



W. Ltndgren "The Gold Belt of the Blue Mountains of Oregon." Twen- 

 ty-second Annual Report of the U. S. Geological Survey, Part II, igoo- 

 1901, pp. 551-776. 

 Lindgren describes and maps the geology of the gold belt of the Blue Mountains 



of Oregon. Gneiss, referred to the Archaean, occurs northwest of Blue Mountain above 



La Belleview mine. 



Bailey Willis. " Stratigraphy and Structure, Lewis and Livingston 

 Ranges, Montana." Bulletin of the Geological Society of America, Vol. 

 XIII (1902), pp. 305-52. 



Willis describes and maps the stratigraphy and structure ot the Lewis and Liv- 

 ingston Ranges of the Front Range of the Northern Rocky Mountains of Montana and 

 Alberta. Lewis and Livingston Ranges consist of stratified rocks of Algonkian age, 

 as determined on fossils which were found by Weller m the lowest limestone of the 

 series, and identified by Walcott as probably being Beltina danai, the species of crus- 

 tacean discovered in the Grayson shales of the Belt Mountains. The Algonkian series 

 consists of limestone, argillite, and quartzite, classified in five formations, and aggre- 

 gating about 12,500 feet in thickness. The formations are the K.intla argillite, 

 Sheppard quartzite, Siyeh limestone, Grinnell argillite, and Appekunny argillite. 

 There is apparent conformity throughout. The series is so situated with reference to 

 other rocks that no lower or upper stratigraphic limit could be determined. Dr. G_ 

 M. Dawson classified with strata as Cambrian, Carboniferous, and Triassic, but it is 

 believed that he mistook certain local overthrust faults for unconformities, and was 

 misled by lithologic resemblances. 



