912 REVIEWS 



Smyth 1 maps and describes the geology of the crystalline 

 rocks in the vicinity of the St. Lawrence River in the towns of 

 Alexander, Clayton, and Theresa, in Jefferson county, together 

 with portions of Rossie and Hammond in St. Lawrence county. 

 The crystalline rocks of the district are discriminated on the 

 map as granite, granite-gneiss, granite-gneiss with much schist 

 and quartzite, schists and quartzites with much granite-gneiss, 

 schists and quartzites of limestone series, and crystalline lime- 

 stone. This classification indicates the close association of the 

 various rocks in the field. Under the term schists are classed a 

 variety of rocks, such as quartzite, hornblende and mica schists, 

 hornblende, pyroxene, and mica gneisses, etc., of both igneous 

 and sedimentary origin. The gneiss formation is not a unit, but 

 rather a complex, so far as age is concerned. It is the most wide- 

 spread of the pre-Cambrian rocks. There is abundant evidence 

 that the granite and granite-gneiss are for the most part younger 

 than the schists and quartzite. The granite has a close genetic 

 relation to the granite-gneiss and is identical with a part of the 

 latter. The granite may be the youngest member of the 

 granite-gneiss complex. The quartzite may have a thickness as 

 great as 500 feet. 



Kemp and Hill 2 report progress of work on the pre-Cambrian 

 formations in parts of Warren, Saratoga, Fulton, and Mont- 

 gomery counties. 



Cushing 3 maps and describes the geology of Rand Hill and 

 vicinitv, Clinton county. The basal rocks are gneisses of the 

 Dannemora formation occurring in the southwestern portion of 

 the area. These are of doubtful origin, but probably mostly 



'"Geology of the Crystalline Rocks in the Vicinity of the St. Lawrence River," 

 by C. H. Smyth, Jr., Nineteenth Ann. Rept. State Geologist of New York, published 

 in Fifty-third Ann. Rept. N. Y. State Museum, Vol. I, 1901, pp. 185-204; with 

 geological map. 



2 " Pre-Cambrian Formations in Parts of Warren, Saratoga, Fulton, and Mont- 

 gomery Counties," by J. F. Kemp and B. F. Hill, Nineteenth Ann. Rept. State Geolo- 

 gist of New York, published in Fifty-third Ann. Rept. N. Y. State Museum, Vol. I, 

 1901, pp. 121-135 ; with geological maps. 



3 "Geology of Rand Hill and Vicinity, Clinton County," by H. P. Cushing, 

 Nineteenth Ann. Rept. Stale Geologist of New York, published in Fifty-third Ann. Rept. 

 N. Y. State Museum, Vol. I, 1901, pp. I 39-182 ; with geological map. 



