128 Reviews — La Face de la Terre. 



"Magmas and Sulphide Ores," by A. -P. Coleman. Econ. Geol., 

 vol. xii, pp. 427-34, 1917. 

 A. discussion of the work of the Ontario Nickel Commission and of 

 Tolman and Rogers on the Sudbury ores. The author maintains 

 that the field relations there seen are in good agreement with the 

 theory of magmatic segregation under gravity, but inconsistent with 

 the deposit of the ores by circulating solutions. 



"Magmatic Ore Deposits, Sudbury, Ont.," by A. M. Bateman. 

 Econ. Geol., vol. xii, pp. 391-426, 1917. 

 A description of the field relations and characters of the nickel- 

 bearing ore-deposits of Sudbury, with a discussion of recent views as 

 to their origin. The author's own hypothesis is that an intermediate 

 magma was differentiated in a reservoir and a portion was extruded 

 to form the "nickel eruptive". This portion then continued to 

 differentiate, giving rise to the successive portions, which vary from 

 granite to pyrrhotite-norite and ore-bodies. 



"On the Geology of the Alkali Rocks of the Transvaal," by H. A. 

 Brouwer. Journ. Geol., vol. xxv, pp. 741-78, 1917. 

 A detailed petrographical description of the Bushveld complex, 

 with a special discussion of the possible origin of the nepheline 

 syenites and allied rock-types of the Pilandsberg area, Leeuwfontein 

 and Lydenburg. It is concluded that these highly alkaline rocks 

 may have been derived by differentiation from the same magma as 

 the granites and norites of the Bushveld. 



"The Problem of the Anorthosites," by N. L. Bowen. Journ. 

 Geol., vol. xxv, pp. 209-43, 1917. 

 The occurrences of anorthosite in the Adirondacks and in the 

 Morin area are described, and it is concluded that the monomineralic 

 rocks of the anorthosite group have probably been formed by gravity- 

 separation of femic minerals from a gabbroid magma. The remaining 

 plagioclase liquid again separates into a basic anorthosite layer below 

 and a lighter syenitic or granitic phase above. 



(To be continued.) 



IRIE'VXIE'W'S. 



I. — La Face de la Terre. Tome III, 4 e Partie (fin). Traduit et 

 annote sous la direction de E. be Margerie, avec un Epilogue par 

 Pierre Termier. pp. xv and 1361-1724, with 3 coloured maps, 

 2 plates, and 115 figures. Tables generalesdel'ouvrage, pp. 258. 

 Paris: Armand Colin. 1918. 



IT is with great pleasure that we welcome the appearance of this 

 the concluding instalment of the French version of Das Antlitz 

 der Erde, and we congratulate M. de Margerie and his colleagues on 

 the successful termination of their labours, in spite of the adverse 

 conditions of the last four years. Although nominally a translation 



