310 GEOLOGICAL RELATIONS OF THE ROCK SYSTEMS 



published in 1857 (a) as the " boulder bed" "the tesselated sandstone" &c. 

 These -beds were here in immediate contact with the beds containing 

 coal : and the pleasure of tracing out in this district the distinct uncon- 

 formity, which existed between the two groups of beds, was reserved for 

 the brothers Blanford, early in 1856. 



In accordance with a well established practice, they gave to this lower 

 group the name Talcheer, from the district in which it had first been 

 satisfactorily made out. 



This separation once established, has been subsequently proved appli- 

 cable in all the other districts, and, chiefly through the labours of Mr. 

 W. T. Blanford himself, the districts already noticed on the skirts of the 

 Rajmahal Hills and in Beerbhoom have been recognized as composed of 

 Talcheer rocks : while the unconformity which exists in Orissa between 

 these Talcheer rocks and the Dannida group above, has been proved to 

 exist also in the Burdwan country (by Mr. Blanford himself), and in 

 other places also, as at Kurhurbari (by Mr. Willson.) The group there- 

 fore, as was fairly and justly anticipated by its first describers, has proved a 

 most important and valuable sub-division. It is one also of great interest 

 from the remarkable persistency in mineral character which it exhibits 

 over such a widely extended area — stretching from close to the shores 

 of the Bay of Bengal, to far west in the Valley of the Nerbudda. It is 

 also, of intense interest, inasmuch as the peculiar character of one at 

 least of its beds seems to give us a clue to the climatal conditions under 

 which it was formed ; and which, if the supposition put forth be well 

 grounded, must have been extremely different from those now obtaining 

 within these tropical regions. 



We shall have occasion to add a few words on the age of these rocks 

 further on. 



Damuda Series. — The fact that there occurred in India, resting un- 

 conformably upon the rocks, of which we have been just speaking, al- 



(a) Memoirs Geol Survey of India, Vol. 1 , p. 33. &c. 



