SR ATIGRAPHICAL FEATURES. 

 This group of formations I divide into — 



59 



Number in 

 sections. 



8. White quartzite with limestone 

 7. Red Crinoid limestone , 

 6. Dark Coral limestone 



Upper \ r , ., 

 r > Larbonire 



Lower ) 



rous. 



Devonian ? 



There is no break between the strata of the upper Silurians 



(6) Dark Coral lime- and the overlying formations in the Central 

 stone devonian? Himalayas. The quartzites of the former are 



frequently replaced by dark limestone beds near the upper limits of 

 the Silurians, and even are seen to alternate with the dark limestone 

 above, and finally become completely replaced by the latter, till the 

 whole is seen to be a limestone formation only, in which here and 

 there a dirty pink quartzite bed is intercalated. A sharp line, where 

 silurian ends and the overlying system begins, can therefore not be 

 drawn, but the lithological character of the mass of the latter is so 

 distinct from the upper silurians that it would have to be separated, 

 even if the traces of fossils found, in it would not necessitate doing 

 such. 



The prevailing rock of this system (6) is a very dark grey, or black 

 limestone in even beds, which are sometimes flaggy, but generally 

 concretionary, and present then the characteristic contact between 

 the strata which in sections may be likened to intricate lines of 

 suture, the beds being as it were closely knitted together. White 

 calcspar veins traverse the system in every direction, and on the 

 fractured surfaces, sections of fossils, chiefly Corals and Brachiopods y 

 appear in large numbers, together with fragments of Crinoids. But 

 very few of these remains can be identified specifically. 



Towards the upper part of the system, some thin partings of cal- 

 careous shales divide the limestone strata ; also red and brown thin- 

 bedded Crinoid limestone of earthy texture appears, and is intercalat- 

 ed with the dark Coral limestone (6) till the system gradually becomes 

 a series of light bluish grey earthy limestone beds, with brownish red 

 beds alternating, both containing Crinoid fragments. 



The total thickness of this formation I found to be about 650 to 



( 59 ) 





