116 GEOLOGY. 



which, is divided, upon geological grounds, into the- following areas : — 

 1. The Lower Ottawa District ; 2. The Gananoque and Back Townships 

 District ; 3. The Lake Ontario District ; 4. The Erie and Huron Dis- 

 trict ; 5. The Manitoulin District ; 6. The District of the Upper Lakes. 



H. A. N. 

 Chase, — . On the Auriferous Sands of Gold Bluff. Proc. Calif. Ac. 



Sci. vol. V. pt. 3, pp. 246, 247; 3 woodcuts (views and section). 

 The gold comes from the bluffs. 



Cole, G. F. The Saltpetre Deposits of Peru. Journ. Soc. Arts, 

 vol. xxiii. no. 1190, pp. 875-880. 



The district referred to comprises the seaboard of Peru, Bolivia, and 

 part of Chile, and consists of a succession of fertile valleys separated by 

 wide arid wastes of high ground. Saltpetre has .only been worked at 

 the southern end of Peru, where the coast is precipitous and with very 

 high cliffs, from the top of which the land rises gently to a plateau of 

 3400 feet. The surface of the plateau is mostly fine sand. " The 

 mineral containing saltpetre is called ' caliche ' " : it " generally lies at 

 depths of from 1 to 10 yards below the surface, and sometimes resem- 

 bles in appearance loaf sugar, and at others rock-sulphur ; and again 

 it ai)pears white, crossed with bluish veins." The methods of working 

 and of extracting the nitrate are described. Two analyses of Caliche 

 are given, showing it to consist of nitrate of soda and common salt, with 

 10 or 12 per cent, of insoluble matters. " The mineral is found in 

 layers of from a few inches to three yards in thickness." The rocks of 

 the district are noticed. The saltpetre- deposits occur on the slopes of 

 hills, and in no case on the pampa above. The author suggests that 

 these deposits may have been derived from the destruction of lava by 

 water, at a time when there was more rain in the country than now, 

 enough to form rivers where now there are none. W. W, 



Cook, Prof. George H. Geological Survey of 'New Jersey. Annual 

 Keport of the State Geologist for the year 1874. Pp. 116. Trenton, 

 1874 (not published till 1875). 



, . Geological Survey of New Jersey. Annual Eeport of the 



State Geologist for the year 1875. Pp. 41, map (not geological). 



[? Published in 1876, though dated 1875.] 8vo. Trenton. 



Report on the Pire and Potter's Clays of Middlesex County, pp. 10- 



12. Water Supply, with analyses and well-sections, 24-33. Miscel- 



aneous Analyses (iron-ores, limestone, clay), 34-38. W. W. 



Cooper, Dr. J. G. Remarks on California Coal. Proc. Calif. Ac. Sci. 



vol. V. pt. 3, pp. 384-386. 

 The coal is Tertiary. 



. California during the Pliocene Epoch. Proc. Calif. Ac. 



Sci. vol. V. pt. 3, pp. 389-392. 

 The climate was tropical. The country consisted of peninsulas and 

 islands. The end of this tropical epoch was marked by volcanic out- 

 bursts and elevation. The Northern Drift does not reach to California ; 

 but there were large glaciers in Post-Pliocene times. W. W. 



