KAMET AND SP1TI. 215 



of the series (5) and the true carboniferous rocks (7 and 8) all inter- 

 vening horizons from upper silurian to lower carboniferous must be 

 included. Sharp boundaries there are none, and the whole represents 

 an unbroken sequence of deposits. 



The carboniferous system is much more fully represented in the 



Spiti area than in the sections eastwards. Not 

 Carboniferous. • 



only are the several formations composing it 



represented in great thickness, but the sequence of horizons is more 

 complete than is the case in Garhwal and Kumaun. The divisions of 

 the system in Spiti are as shown on page 212 ; the limestone (8, a) is 

 wanting in all the eastern sections, — eroded I believe before the black 

 Productus shales were laid down on it. The lower boundary between 

 this system and the underlying dark Coral- limestone (6) is not well 

 defined. 



The lowest horizon which 1 take to belong to the lower car- 

 Earthy grey CHnoid boniferous is an earthy grey limestone (7) of 

 limestone (7). irregular thickness and not very conspicuous. 



It might easily be altogether overlooked or considered part of the 

 underlying C^raZ-limestone (6), if I had not observed it in the Dharma 

 section more amply developed. Here, as there, it is characterized by 

 the presence of Crinoid remains, which are found throughout this and 

 the succeeding division. The passage from this grey limestone into 

 Red Crinoid lime- the overlying Red Crinoid limestone (7, a) is 

 stones (7, a). gradual, and the former seems altogether a local 



development only of the latter. Together, the two series may be 

 from 600 to 800 feet in thickness. With the exception of badly-pre- 

 served Orthoceras fragments, nothing but Crinoid remains were 

 found in this series ; but the rock is so constant over the entire area 

 of the Central Himalayas that a mistake is absolutely impossible. Its 

 colour, a brownish-red (Indian red), distinguishes it everywhere, and 

 often helped me in making out the structure of the upper palaeozoics 

 in mountain tracts which were only partially accessible to me. Its 

 intense colouring, coupled with the fact that it is nearly invariably 

 overlaid by the glaring white quartzite (8), serves as an unfailing 



( 215 ) 



