STRATIGRAPHICAL FEATURES. 6l 



with neighbouring ones, which are undoubtedly normal, it would be 

 premature to say whether the sections in Spiti which seem more fully 

 developed than the carboniferous elsewhere in the Central Himalayas 

 are complete in that respect or not. 



At present I found that the carboniferous system consists of the 

 following divisions in descending order : — 



Number in the 

 figured sections. 



8a. Dark limestone with Productus sp. only seen in ^ 



Spiti. C Upper carboniferous. 



8. White quartzite ) 



7. Red Crinoid limestone ..... Lower carboniferous. 



I adopted this term during my first season's work in the Himalayas, 

 (7) Red Crinoid a rec * C rt ' n °id limestone forming the most charac- 

 hmestone. teristic portion of the division. Later on when 



1 found that the horizon is a most constant one throughout the Central 

 Himalayas, and that the brownish red earthy limestone remains litho- 

 logically the same over the whole area, I allowed the term to stand. 



There is no sharp boundary between the underlying devonian 

 Coral limestone (6) and this division. Earthy, dark grey, or brownish 

 red limestones, mostly thinly stratified but always yielding Encrinite 

 fragments, are intercalated between the Coral limestone near its upper 

 limit, gradually increasing in frequency, and finally the formation be- 

 comes entirely a Crinoid limestone, which I distinguish in map and 

 section as division (7) of the lower carboniferous. In the eastern- 

 most sections of the Upper Dharma valley, near the head of the Kali 

 river (in Byans) and at the Lipu Lek pass, the intercalated beds are 

 generally light bluish grey earthy limestone, which swells out into 

 a division, not less than about 600 to 700 feet thick, and is 

 followed by densely red brown and red earthy limestone, of about the 

 same thickness, both formations containing besides other fossils in 

 poor preservation, many Crinoid fragments. 



In the Painkanda sections the bluish grey limestone beds at the 

 base of this division are entirely wanting; the red Crinoid limestone 

 rests directly on the Coral limestone (6). 



( 61 ) 



