278 PETROLOGICAL ABSTRACTS AND REVIEWS 



GoLDBECK, Albert T., and Jackson, Frank H. The Physical 

 Testing of Rock for Road Building. Bull. 44, Office of Public 

 Roads, U.S. Dept. of Agriculture, Washington, 191 2, Pp. 96, 

 figs. 20. 



Graton, L. C., and Murdoch, Joseph. "The Sulphide Ores of 



Copper. Some Results of Microscopic Study," Trans. Amer. 



Inst. Min. Eng., New York meeting, Feb., 1913, 741-809. 



While this paper is principally of interest to the economic geologist, it 



is of importance to the petrographer from the authors' work on the 



determination of ore minerals by means of the microscope. This is a 



problem which has only recently been attacked, and in the solution of 



which but little has been done. It opens up a new field to petrographers, 



and promises to be of great importance in the deter mination of opaque 



minerals. 



A. J. 



GwiLLiM, Faribault, and Barlow. Report on the Geology and 

 Mineral Resources of the Chibougamau Region, Quebec. Quebec, 

 1911. Pp. 216+viii, pL 78, figs. 19, maps 2. 

 Numerous rocks and minerals are described and illustrated. A 

 number of analyses is given. 



Harder, E. C. "Structure and Origin of the Magnetite Deposits 

 near Dillsburg, York County, Pennsylvania," Econ. Geol., 



V (1910), 599-622. ^ 



Hatch, F. H., and Rastall, R. H. Text Book of Petrology; The 

 Sedimentary Rocks. London, George Allen & Co. Pp. 525, 

 figs. 60. 



While there is a wealth of literature regarding the sedimentary rocks, 

 the processes which produce them, and their metamorphic equivalents, 

 this volume represents the first published attempt, in English, to bring 

 the knowledge of the subject together. About one-third of the book is 

 devoted to the sedimentary rocks, and the balance to the metamorphic 

 processes and the metamorphic derivatives of the sediments. The 

 subjects cementation, metasomatism, contact metamorphism, regional 

 metamorphism, and weathering are included. 



Though no classification of the sediments has been generally agreed 



