176 • REVIEWS 



The Geology of Northeastern Rajputana and Adjacent Districts. By 

 A. M. Heron, B.Sc, F.G.S., Assoc. Inst. C.E., Assistant 

 Superintendent Geological Survey of India. Calcutta : Memoirs 

 of the Geological Survey of India, Vol. XLV, Part I, 191 7. 

 Pp. 128, pis. 26. 



This report gives the results of a general geological survey of the 

 region started in 1908, made with special reference to stratigraphy. 

 The formations present include only the pre-Cambrian overlain by 

 unconsolidated post-Tertiary beds. The chief physiographic feature is 

 that of an ancient, folded, mountain complex, in the last stages of 

 denudation, surrounded by gently sloping plains. There is a general 

 discussion of local correlations and nomenclature. 



There is no mineral wealth of any great importance. Quartzite is 

 quarried rather extensively, but chiefly for local use. The report is 

 accompanied by a geologic map and a number of structure sections. 



A. C. McF. 



The Phosphate Deposits of South Australia. By R. Lockhart 

 Jack, B.E., F.G.S. Adelaide: Geological Survey of South 

 Australia, Bulletin No. 7, 1919. Pp. 135. 



The author considers briefly the mode of occurrence, sources, method 

 of working, and the preparation of the rock phosphate. Both guana 

 deposits and rock phosphate are worked. The latter is associated with 

 sedimentary rocks of Cambrian or even possibly pre-Cambrian age 

 which are usually highly metamorphosed. It is almost invariably 

 found in close association with the limestones and marbles or the adjoin- 

 ing argillaceous rocks. Whether the phosphate is primary or secondary 

 is not known. Brecciation of the associated rock is conspicuous even 

 at considerable depth. 



A. C. McF. 



Systematic Report on the Cambrian and Ordovician of Maryland. 

 By R. S. Bassler. Maryland Geological Survey, 1919. 

 In a review of this report in the last issue of this Journal, it was 

 stated that the proposed Ozarkian and Canadian systems "are not 

 recognized" instead of "are recognized." It is the desire of the reviewer 

 to call attention to this correction. The two systems are not only 

 recognized but are discussed in some detail, the Conococheague lime- 

 stone being referred probably to the former, and the Beekmantown 



limestone to the latter. 



A. C. McF. 



