50 GRIESBACH : GEOLOGY OF THE CENTRAL HIMALAYAS. 



Previous notice. 



In his paper on the Geology of the Himalayas, 1 General R. Stra- 



chey describes this complex of strata as the 

 " azoic slate " series, and he gives the geographi- 

 cal distribution of the formation correct in the main outline ; at the same 

 time he over-estimates the total thickness of the system very greatly, 

 namely, upwards of 9,000 feet in all. I consider that the total thick- 

 ness of this system is certainly not more than 4,000 feet at the most. 



Stoliczka, 2 in his Memoir on Spiti, identifies certain slates and 

 quartzose strata as lower silurian ; but he also suggests that this 

 group might turn out to be the same as Strachey's azoic slates. I 

 have seen Stoliczka' s section in Spiti, and have certainly no hesitation 

 in saying that it is so. In Spiti as elsewhere in the Central Himala- 

 yas these " slates" underlie conformably the lower Silurians, and 

 must be separated from the latter. 



As this system underlies conformably the lower Silurians, it may 



be inferred that the entire Cambrians are in- 

 eluded within its thickness; the latter however 

 is so great, and it is also very probable that horizons much older than 

 Cambrians are represented in it, that it seemed best to comprise the 

 whole system under one name, leaving it to future researches to 

 classify and divide it further. The term "azoic" is inapplicable, as 

 traces of organic remains have been found by me in its upper divi- 

 sion ; Stoliczka's name Babeh series would ill define it, as under that 

 name some members of the Silurians have been included by Stoliczka, 

 and finally therefore I had to think of a new and more convenient 

 name to give to the whole system. The word haimanta will express 

 in this memoir all the thickness of strata lying between the crystallines 

 (gneiss and vaikritas) and the lower silurians ; with few exceptions, the 

 system lies within the area of perpetual snow, hence the name haimanta, 

 which in Sanskrit signifies snow-covered. 



Throughout the Central Himalayas, as far 1 have examined them, 



Divisions of the hai- * found the haimantas most constant both in 



manta system. lithological aspect as well as in thickness. I 



1 Quart. Journ. Geol. Soc, VII, 292-310., 1851. 



2 Mem., Geol. Survey of India., Vol. V. 



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