Geology and Mineralogy. 389 



II. Geology and Mineralogy. 



1. United States Geological Survey. — The following publica- 

 tions have recently been issued. 



Twenty-first Annual Report, Pt. III. 644 pp., 68 pi., 104 

 figs. — This volume contains papers on general geology, ore 

 deposits and the Philippines. Professor Hobbs's report on the 

 Newark System of Pomperaug Valley, Conn, (reviewed in this 

 Journal, vol. xiii, p. TO), occupies pp. 19-160. " The Laccoliths 

 of the Black Hills" by Professor Jaggak (pp. 163-303) is a 

 description of the interesting intrusions of rhyolite and phonolite 

 in western South Dakota and eastern Wyoming. The laccoliths 

 are so numerous and the amount of erosion so varied that all 

 parts of a typical intrusion — conduit, basement contact, wedge, 

 flank, crest — are exposed, in different parts of the region. These 

 intrusions are assigned to the Eocene and are an effect, not the 

 cause, of the great fractures and dome uplift of the Black Hills. 

 "The fractures reached downward to a zone where molten rock 

 was under pressure. The liquid shot upward into every ramifi- 

 cation of the fracture system." Ernest Howe has made an 

 extremely interesting series of laboratory investigations (pp. 

 291-303) imitating the processes of laccolith intrusion and con- 

 sequent deformation of the invaded beds. Professor Van Hise 

 contributes a paper (pp. 313-434) on the "Iron Deposits of the 

 Lake Superior Region " in which both the geologic and economic 

 aspects of the area are discussed. The Arkansas Bauxite and the 

 Tennessee white Phosphate deposits are described by C. W. 

 Hayes, pp. 435-487. "The Report on the Geology of the Phil- 

 ippine Islands" (pp. 493-625) is by G. E. Becker. It contains 

 general descriptions of the rock types and formations, the min- 

 eral resources, a bibliography and a paper by K. Maetin on Ter- 

 tiary fossils. 



Twenty-first Annual Report, Pt. IV. V41 pp., 156 pi., 

 329 figs. Hydrography ; by F. H. Newell, Hydrographer in 

 charge. The tabulation and interpretation of stream measure- 

 ments for 1899 has added much data which is essential if intelli- 

 gent use is to be made of the water resources of the country. 

 Work has been carried on in all parts of the country, and the 

 descriptions (pp. 45-488) are so given as to render the facts 

 directly useful to interested people. A special paper on the 

 Geology and Water Resources of the Black Hills region (pp. 489- 

 599) is written by N. H. Darton. (Reviewed in this Journal, 

 vol. xiii, p. 68.) "The High Plains and their Utilization," by 

 WiLLARD D. Johnson (pp. 609-741) is an interesting study of 

 the topography, climate and history of the region including parts 

 of Texas, Kansas, Nebraska, New Mexico, and Colorado. The 

 causes of agricultural failure and the conditions necessary to suc- 

 cess are discussed in the light of recently acquired knowledge of 

 soil character, streams and underground water. 



Monograph XLI. — Glacial Formations and Drainage features 



