Reviews — Geological Survey — Geology of India. 121 



III. — Geology of India. 



Genekal Eepoet of the Geological Sukvet of India foe 1906, by 

 T. H. Holland, F.E.S., F.G.S., Director. The Mineral Production 

 of India during 1905, by T. D. Latouche, B.A., F.G.S. The 

 Geology of the State of Panna, principally with reference to the 

 Diamond-bearing Deposits, by E. Vredenburg, A.R.C.S., F.G.S. ; 

 also numerous papers on Indian Geology by the same author. 

 A Preliminary Survey of certain Glaciers in the North-West 

 Himalaya, by Officers of the Geological Survey of India. — All the 

 above extracted from the "Records." 



PARTLY in continuation of a review of the Geology of India 

 which appeared in the Geological Magazine for July, 1907, we 

 are now able to offer a few additional remarks on the progress of this 

 far-reaching Survey. When we reflect that the area under con- 

 sideration, though nominally India, extends from the crest of the 

 Karakoram in Central Asia to the southernmost point of the Nicobar 

 Islands, and from the confines of Persia on the west to those of 

 Chinese Yunnan on the east, it must be admitted that this is a truly 

 Imperial Survey, and that the variety of formations must afford 

 a wide scope for official enterprise. 



There are of necessity so many and such diverse subjects dealt with 

 in this Report and the accompanying papers that it seems advisable, 

 for the purposes of review, to alter somewhat the arrangement 

 adopted by the Director, and to place the several subjects more or 

 less on a chronological basis so far as this is practicable. 



JExisting phenomena. — There are two subjects dealt with in this 

 category. 



(1) " River action." Mr. Holland drew the attention of the Board 

 of Scientific Advice to the unsatisfactory nature of our information 

 regarding the data available as to the amounts of silt and dissolved 

 salts carried by the large Indian rivers to the sea, and, on the 

 recommendation of the Board, Government sanctioned the institution 

 of systematic investigations. These, it is thought, will materially 

 assist in the estimation of the amount of denudation going on, and be 

 of much interest to geologists. Steps have been taken, notably in the 

 case of the Indus, to determine the amounts systematically. This is 

 for many reasons an excellent move, but the problems of denudation, 

 which it is hoped to solve, must of necessity be complicated where 

 the rivers drain such a rare and exceptional area as that occupied by 

 the Himalayan system. The rivers of Central India might yield 

 results of a more normal character. 



(2) " Himalayan glaciers." The importance of determining the 

 secular movements of these glaciers has been recognized, and 

 a preliminary survey of the principal ones in the Kashmir, Lahaul, 

 and Kumaon region instituted. Of all these glaciers plane-table 

 sketches were made showing the exact positions of the ' ice-caves ' 

 with reference to points fixed on rocks in the valleys, as well as with 

 reference to prominent and unmistakable peaks in the vicinity. In 



