REVIEWS 59 



A, P. Coleman. " Nepheline and Other Syenites Near Port Coldwell," 

 Ontario. American Journal of Science, Vol. CLXIV (1902), pp. 147-55. 

 See also Report of Ontario Bureau of Mines for (1902), pp. 208-13. 



Coleman describes nepheline and other syenites near Port Coldwell, Ontario, 

 and calls attention to their widespread distribution in Ontario and the United 

 States. 



W. G. Miller. " Nepheline Syenite in Western Ontario," Anierican 

 Geologist, Vol. XXXII (1903), pp. 182-85. 



Miller describes bowlders of nepheline syenite near Sturgeon Lake, northwest of 

 Lake Superior, indicating the occurrence of rocks of this character in the pre- 

 Cambrian rocks farther north. 



R. G. McCoNNELL. " Note on the So-called Basal Granite of the Yukon 

 Valley." American Geologist, Vol. XXX (1902), pp. 55-62. 



McConnell describes the granite gneiss of the upper part of the Yukon Valley, 

 extending fron:i the Nordenskiold River in a northwesterly direction across the 

 White River valley to the Tanana, and down this stream to near the mouth of the 

 Delta River — a total distance of about 380 miles — and concludes that a part of the 

 gneisses at least must be regarded as intrusive through, and therefore younger than, 

 the clastic schists associated with them. It is still possible, however, as the work 

 done so far has been largely of an exploratory character, that older gneisses may be 

 present in the district, but no evidence of this was obtained in the course of the 

 investigation. 



O. H. Hershey. "Structure of the Southern Portion of the Klamath 

 Mountains, California." Atfiericatt Geologist, Vol. XXXII (1903), pp. 



231-45- 



Hershey discusses the structure of the southern portion of the Klamath 

 Mountains, of California. The oldest rocks in the mountains west of the Sacramento 

 River are the Abrams mica-schists, 1,000 feet thick, and overlying it the Salmon 

 hornblende-schist, known to be at least 2,500 feet thick, both of them supposed to be 

 of pre-Cambrian age, probably Algonkian, and possibly Archaean. The Abrams 

 mica-schist is a sedimentary rock, and the Salmon hornblende-schist is a metamorphosed 

 volcanic ash. The Klamath schists form the central ridge of the Klamath region. 

 They are bordered on the west by a great, unsymmetrical geosyncline, and on the east 

 by the western limb of another great geosyncline. The first geosyncline is limited on 

 the west by another belt of schist, chiefly the Abrams mica-schist, which forms the 

 South Fork Mountain and is prolonged northwestward to and probably across the 

 Klamath River near Wichiper. The sandstones of the Coast Range region adjoin 

 this schist belt on the west. According to Mr. Diller, toward the north, 

 approaching the Klamath River, long narrow belts of schist alternate with narrow 

 belts of sandstone, the latter dipping eastward as though going under the schists. 

 This apparent anomaly is evidently due to a series of faults. It is further evident 

 that the Coast Range formations have buried the western portion of the schist belt 

 which may extend, immediately under the sandstone, far toward the coast. 



The eastern schist belt emerges from beneath the Cretaceous sandstones and 

 shales in the Sacramento valley west of Ono, with a width of eight miles and 



