MEMOIRS 



OF 



THE GEOLOGICAL SURVEY OF INDIA. 



Geology of Western Rajputana, by Tom D. La 

 Touche, B.A., Superintendent, Geological Survey of 

 India. 



CHAPTER I.— INTRODUCTION. 



The Geological Survey of Western Rajputana, of which the present 

 memoir is the outcome, was primarily undertaken as a continuation 

 of Mr. R. D. Oldham's investigations in the years 1885-87 regarding 

 the possibility of the existence of Gondwana coal measures in Jaisalmir. 

 The presence of boulder beds of glacial origin at Pokaran and 

 other places between Jodhpur and Jaisalmir had been noted by 

 Mr. W. T. Blanford in 1876. These beds were supposed by him to 

 underlie the Vindhyan sandstones of Jodhpur, but Mr. Oldham found 

 that similar beds occurring at Bap, about 40 miles north-west of 

 Pokaran, contained boulders of Vindhyan limestone, and he identified 

 them as Talchirs, " the beds which everywhere in India underlie the 

 coal measures." 1 The existence of strata of upper Gondwana age had 



1 Rec. Geol Surv. Ind, Vol. XIX, Ft. 2, p, 123 



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