CAMBRIAN IN THE HIMALAYAS. 47 



these boulders are firmly embedded is nearly always a hard flinty quartz rock, sometimes 

 partially schistose. It is by far one of the most characteristic and easily recognized hori- 

 zons of the central Himalayas, and is invariably met with in all Haimanta sections which I 

 have seen. 



Again on page 96: 



This conglomerate, which in places strongly resembles a boulder-bed, merges into 

 massive, intensely hard, dark-purple quart/ites. 



And on page 159: 



The mineralogical character of the shales and quartzites lying below the typical 

 purple quartzites with the boulder-bed (conglomerate) and the adjoining metamorphic 

 schists, Vaikritas, merge into one another. 



It is of interest to note the descriptive term, " boulder-beds," by which 

 the conglomerates of the early Cambrian are designated, since we have dis- 

 covered glacial deposits, probably of that age, on the Yang-tzi, in a region 

 which, though 1,850 miles, 3,000 kilometers, distant, is practically in the 

 same latitude, 31 north. However, the conglomerate was not regarded as 

 a true boulder-bed of glacial origin by Griesbach, who, with reference to 

 the ancient shore-line in the western Himalayas during the Haimanta age, 

 states that he regards these deposits to be evidence of "a chain of eleva- 

 tions, from the waste of which the boulders and pebbles of the Haimanta 

 conglomerate were derived." An inquiry addressed to Dr. Holland, the 

 present director of the Indian Survey, has brought a negative, though 

 perhaps not decisive, answer: 



The question of the possible existence of Pre-Carboniferous glacial deposits in India is 

 one which has recently received considerable attention. You are, no doubt, familiar with 

 the published description of the Blaini boulder slate of the Simla area, the glacial origin of 

 which is generally admitted. This formation was, until recently, regarded as possibly of 

 Upper Paleozoic age, corresponding to the well-known Talchir and Salt Range boulder- 

 beds; but there has been of late a general tendency to correlate the series of beds with which 

 it is associated with the old, probably Pre-Cambrian, sediments of the Peninsula. I first 

 drew attention to this in my General Report of the Geological Survey (1903-04) published 

 in Records Geological Survey of India, vol. xxxn (page 156) and the conclusion based 

 admittedly on negative evidence has received some support from the recent discoveries of 

 Pre-Cambrian boulder slates both in Australia and in South Africa. In this connection, 

 the occurrence of a typical boulder slate among the pre-Vindhyan rocks of the Son Valley in 

 Rewa State is also of considerable interest (Memoirs, Geological Survey of India, vol. xxxi, 

 p. 132); but it should be remembered that no striated boulders have been found in the 

 Himalayas or in the Son Valley. 



The possibility of the occurrence of a representative of the Blaini boulder slate in associ- 

 ation with the fossiliferous beds of Gurhwal and Kumaon has been steadily kept in view dur- 

 ing the progress of geological surveys in the Himalaya, and it may be assumed that, during 

 his survey, Mr. Griesbach would have had this in mind when studying such a rock as the 

 boulder-bed that he describes, and would have been on the lookout for evidences of glacial 



