Geology and Natural History. 465 



Plateau-like mountains with a height of 5,000 to 5,500 feet form 

 dominant topographic features and are described as "conspicuous 

 examples" of block mountains with intervening graben. The 

 mountains are described as possessing " no great descending 

 spurs or ridges and no foot-hills," and the streams in the inter- 

 vening basins have experienced an interesting life history. The 

 Manuherikia basin, in particular, is marked out by faults, one on 

 each side of the valley, and the drag on the country rock adjoining 

 the faults is marked and furnishes criteria for determining the 

 date of the fault as later than Pliocene. Definite fault rifts 

 which have controlled the courses of streams are described. The 

 region exhibits also great thicknesses of glacial and alluvial 

 deposits. Bedrock is made up of two series : one, Manuherikia, 

 Pliocene, consists of "cement stone," sandstone, sands; the 

 other, Maniototo, Paleozoic, consists of schists of various types. 

 The unusual "cement stone" consists of quartz sands and gravels 

 cemented into a stone by siliceous waters " which probably had 

 some genetic relation to the great lines of fault structure." 

 Petrography is well represented in this report, microscopic 

 descriptions with excellent photographs being given of most of 

 the rock types. Chemical analyses have been made of mica 

 schist, chlorite schist and quartz schist. In the discussion of 

 economic geology of the region the theories of ore deposition 

 receive considerable attention. h. e. g. 



4. Cape of Good Hope Geological Commission. — Three 

 sheets of the new geological map of the Cape of Good Hope 

 have been received. Sheet 2 covers an area east of Cape Town, 

 including the coast line from Struis Bay to Cape Barracouta. 

 Sheet 4 includes the valley of the Great Berg River and extends 

 from the coast at Saldanha Bay eastward to longitude 16°. Sheet 

 45 includes an area between parallels 27° 40' and 28° 40' and lon- 

 gitude 22° 40' and 24°. The maps are printed in color on a 

 scale of 1 to 238,000. These maps embody the work of A. W. 

 Rogers, E. H. L. Schwartz and A. L. DuToit, and are published 

 by the Geological Commission. 



5. The Stone Implements of South Africa; by J. P. Johnson. 

 Pp. 53, with 258 illustrations. London, 190*7 (Longmans, Green 

 and Co.). — During the past four years Mr. Johnson has made 

 numerous discoveries relating to the Stone Ag« of South Africa. 

 Descriptions and illustrations of the " finds " are now given. 

 Primitive, Paleolithic and Advanced groups are recognized and 

 their relationship in time is indicated by numerous specimens of 

 stone implements of various types. The Paleolithic groups are 

 shown to be of "great antiquity." A gradual evolution of im- 

 plements from the Eoliths to the weapons and implements of the 

 present native races is indicated and the suggestion is made that 

 the Bushmen may have been the makers of the stone implements. 

 "If so, they belong to a more backward epoch of the Stone Age 

 than the contemporary aborigines of either America or Australia." 



Am. Jour. Sci.— Fourth Series, Vol. XXIII, No. 138.— June, 1907. 

 32 



