78 



GRIESBACH : GEOLOGY OF THE CENTRAL HIMALAYAS. 



Zanskar and Kashmir. 



the same lithological characters. From the Upper Lissar valley in 

 Eastern Kumaun, to North-Western Spiti, they have been traced 

 in patches which are preserved in synclinals of rhaetic and lias beds. 

 Stoliczka's observations show that the Spiti shales occupy a wide 



range from the Spiti valley to Zanskar and be- 

 yond, where he has found them north of the Kara- 

 korum pass. 

 The upper Jurassic strata of HazaYa have also been identified with 



the Spiti shales of the Himalayas, and I believe 

 Haz5ra and Sulaiman . 



range. Khorassan and that an upper Jurassic horizon, scarcely differing 



it i rki si" 3 n 



if at all in lithological character, will be found 

 to underlie the lower cretaceous in all the sections through the 

 latter system in the North-Western Frontier districts. In the Sulaiman 

 range, dark shales with calcareous concretions occur which strongly 

 reminded me of the Spiti shales. 1 They are immediately overlaid, or 

 pass into grey marly shales with badly preserved Ammonites ; the 

 whole being conformably overlaid by the lower cretaceous sandstones 

 of the Takht-i-Sulaim£n. 



Later on, I htod an opportunity of studying the sections north of the 

 Hindu Kush and in Khorassan, and in both found a great thickness of 

 dark crumbling alum shales, which are conformably overlaid by red 

 and brown coarse sandstone and grits (my " red grit group " of 

 former papers) of neocomian age. This is, in fact, the Sulaiman section 

 with very slight lithological differences. It is known that the 

 same succession of black crumbling shales with Jurassic fossils, over- 

 laid by neocomian sandstone, runs through the entire north of Persia, 

 and is again met with near the shores of the Caspian, forming one of 

 the most constant of geological horizons. 



There is, however, one feature, which distinguishes the true Spiti 

 shales from the dark alum shales of Khorassdn and Turkistcin, namely 

 this : the Spiti shales are essentially a marine formation, containing 

 as far as known nothing but a marine fauna, whereas the alum shales 

 of the Afghdn-Persian area are nearly entirely a littoral formation, as 



1 Records, XVII, p. 184. 



< 7* ) 



