REVIEWS 179 



J. E. Todd. "The Newly Discovered Rock at Sioux Falls, South Dakota." 



American Geologist, Vol. XXXIII (1904), pp. 35-39. 



Todd reports the presence of gabbro within one-half mile of the Sioux quartzite 

 of South Dakota. He believes it to be intrusive into the quartzite, although no con- 

 tacts are found. 



E. R. Buckley and H. A. Btjehler. "Quarrying Industry of Missouri." 

 Missouri Bureau of Geology and Mines, Vol. II (2d Ser., 1904). With 

 geological map. 

 Buckley and Buehler map and describe the pre-Cambrian granites of southeastern 



Missouri in connection with a report on the building-stones of the state. 



J. D. Irving. "Economic Resources of the Northern Black Hills." Part I, 



"General Geology" by T. A. JaGGAR, Jr., Professional Paper No. 26, U. S. 



Geological Survey, 1904, pp. 13-41. With geological map. 



Jaggar describes the general geology of the Black Hills and gives particular atten- 

 tion to the dynamics of the later intrusions of the northern part of the uplift. The 

 southern portion was occupied by massive ancient pegmatite granites, themselves pre- 

 Cambrian intrusives in Algonkian strata. Probably they acted as a rigid cementing 

 and hardening agent to prevent fracturing in the southern schists; the northern, less 

 indurated phyllites cracked and faulted more readily to permit the younger intrusives 

 to rise from the depths. The northern exposed schist areas contain many hundred 

 dikes and some stocks; these must have induced movements of horizontal extension 

 in the schist, and such movements are attested by bedding-plane faults at the base of 

 the Cambrian. The dikes have a common trend and dip parallel with schistosity. 

 The dip gave them tendency to spread in the Cambrian in one direction more readily 

 than in another. 



Two illustrative sections are given. North of the Homestake mine on Deadwood 

 Creek, near Central, Algonkian rocks appear as follows from west to east: graphitic 

 schist, mica-schist, heavy ferruginous black schist with quartzite bands cut by irregular 

 white quartz bodies which form a distinct zone, ferruginous schist, mica-schist, all 

 dipping toward the east; mica-schist with thin sandstone stringers, dipping to the west. 

 This sudden change of dip just opposite the De Smit and Homestake ore bodies is 

 significant, and suggests that perhaps the great ore body may fill a synclinal saddle 

 pitching to the southeast. 



A section from north-northwest to south-southeast along the ridge northeast of 

 the Clover Leaf mine is: garnetiferous mica-schist, graphitic schist, ferruginous quartz- 

 ite, amphibolite, mica-schist, white quartz, mica-schist, amphibolite, quartzite, and 

 amphibolite. 



Joseph A. Taff. "Preliminary Report on the Geology of the Arbuckle and 

 Wichita Mountains in Indian Territory and Oklahoma." Professional 

 Paper No. 31, U. S. Geological Survey, 1904. With geological map. See 

 also Geologic Atlas of the United Slates, Folio No. 98, U. S. Geological 

 Survey, 1903. 



Taff describes and maps the geology of the Arbuckle and Wichita Mountains in 

 Indian Territory and Oklahoma. In the Arbuckle Mountains, unconformably below 

 middle-Cambrian sediments, are granite, granite-porphyry, and aporhyolite containing 

 basic dikes. The granite (Tishimingo) occurs in the eastern part of the mountains in 



