STRATIGRAPHICAL ELEMENTS: JURASSIC. 2g 



At the base of the Trias limestone to the south-east of Bugnotur 



above the quartzites (i) there are some grey- 

 Some doubtful fossils. ,. . . , • i t j c c m i j« 



shales which yielded a few fossils, including 



fragments of a cephalopod and some bivalves, all too imperfect for 

 identification. It is possible, however, that this horizon is lower 

 than the Magalodon beds, and it may even be Permian or Carboni- 

 ferous. 



Dr. Verchere writing in 1867 1 described and figured a section 

 at the north end of the Sirban spur, that is to 

 vaHonI erCh ' re ' S ° bSer " say across the spur E of Shakur-Bandee (see 

 infra, p. 1 12). In this he recognised the'volcanic 

 rocks at the base of the stage ; but he called the Trias limestone 

 Carboniferous and classed it with his Weean and Kothair groups of 

 Kashmir, the former being the zone of Spirifer Stracheyi and Spirifer 

 Keilhavii. He also regarded certain rocks from the Niti pass con- 

 taining similar fossils as of the same age. Thus although speaking of 

 the Sirban rock as Carboniferous, he classed it correctly with groups 

 now known to be of Triassic age. 



(IV) Jurassic series. 



The Jurassic series lies directly upon the Trias limestone in every 

 section that has been seen of its base. Not- 

 ^Stratigraphical posi- withstanding this, there seems to be good evi- 

 dence for a slight stratigraphical break between 

 it and the Trias, at least in certain parts of the district. Waagen 

 and Wynne first drew attention to this in the neighbourhood of 

 Tanakki, where the surface of the underlying limestone is eroded, 

 overlapped by the Spiti shales (Jurassic), and pierced by the shells 

 of boring molluscs. Further examples of this will be given in the 

 detailed sections to follow, and it will be shewn that the bottom 

 ferruginous layer of the Spiti shales covers the step-like outcropping 

 edges of the Trias after the manner of a stair-carpet. In addition, 



1 Journ. As. Soc, Bengal, Vol. XXVI, p. 28, et seq. 



f 29 ) 



