Geology and Natural History. 435 



On the seaward side of the Coast Ranges, the Cretaceous rocks, 

 where they occur, are found likewise to have participated, to a 

 considerable degree at least, in an upturning of the older strata ; 

 and on the inner side of Vancouver Island some of these rocks are 

 probably of a date as recent as that of the typical Laramie. 



2. Preliminary Report on the Coal-deposits of Missouri from 

 field work in 1890 and 1891, by Arthur Winslow, State Geolo- 

 gist. 226 pp. with a map of the area of the coal measures and 

 many wood-cut illustrations. — The area occupies the western and 

 northwestern parts of the State and covers about 23,000 square 

 miles. The rocks are sandstones and shales of various colors, the 

 shales predominating, and they are horizontal or nearly so. The 

 maximum thickness of the measures is 1900 feet. The coal beds 

 are thin, and about a fourth of the annual Missouri supply, 

 which amounted in 1891 to about 2,680,000 tons, comes from 

 those that are not more than two feet thick. The Report treats 

 of the origin of the coal measures and the special characters of 

 the Missouri coal, and gives detailed descriptions of the beds 

 that are worked. 



3. Baltimore, with an account of the Geology of its environs. 

 140 pp. 12mo, with three maps and other illustrations. Pre- 

 pared by the Local Committee of the American Institute of Min- 

 ing Engineers, Baltimore meeting, February, 1892. — Nearly one- 

 half of this little volume treats of the geology of the vicinity of 

 Baltimore : the part on the crystalline rocks and their products 

 is by Prof. George H. Williams of Johns Hopkins University, 

 and that on the sedimentary rocks, by N. H. Darton, of the 

 U. S. Geological Survey. 



The broad belt or plateau of crystalline rocks, lying to the 

 eastward of the Appalachians, — the Piedmont plateau, as it has 

 been called — is described by Prof. Williams as consisting of an 

 eastern belt made up mainly of highly crystalline rocks and a 

 western of semi-crystalline rocks. Of the latter it is stated there 

 is reason to believe that they will yet afford fossils and have their 

 age determined thereby. Small areas of the latter rocks occur 

 also among the former. The conclusion reached with regard to 

 the origin of the i*ocks is that the eastern rocks are in the main 

 the older, and that over a floor consisting of such rocks, the beds 

 of the western were deposited. The upturning and metamorph- 

 ism of the latter are referred with a query to the time of the 

 Appalachian mountain-making, but without mentioning evidence. 

 The eastern lie within the range of the Archaean Appalachian pro- 

 taxis. They include gabbro, both massive and schistose, pyrox- 

 enyte and peridotyte (rocks without any feldspar), with their 

 alteration products, serpentine and steatite, granite, gneiss, crys- 

 talline limestone and quartzytic schist. All the massive rocks 

 are made eruptive. Both the granite and gneiss contain coarse 

 granite veins (pegmatyte), and, on very doubtful evidence, those 

 in the granite are believed to be eruptive. Mr. Darton's contri- 

 bution occupies 15 pages and treats of the formations of the 



