Chap. II.] general topography and geology. 25 1 



of 18 miles in each case. The area contained in this belt of somewhat 



irregular breadth is about 500 square miles. 



The general geology is simple. A series of between 11 and 12,000 



feet of rocks, dip in succession from the Northern 

 Geology. 



boundary, at angles varying from 5° to about 20° 



towards the South. All are suddenly cut off at the Southern boundary 



by one of the largest distinct faults that has ever 

 Great S. fault. 



been carefully observed and recorded. There is 



some crumpling of the strata near this fault, and at about 4 or 5 miles 



North of it, there is a roll of the beds throughout a considerable area. 



The dip changes from S. S. W. in the East of the field and to the 



North of Kaniganj, to S. S. E. as it approaches the Barakar, "West of 



which river it recurs to S. S. W. : the general direction of the dip 



throughout being, as already stated, Southernly. It increases in amount 



considerably towards the West, causing great contraction in the width 



of the field, the same thickness of rocks, or even more, cropping to the 



surface between the North base of Panchet Hill and Debitan on the 



Barakar, a distance of 10 miles,* or between Hiraptir, East of 



Chinakuri, and Dendwa near Jamiari, a distance of 9 miles, as between 



Kastura, South of the Damuda, and the boundary North of Birkunti, 



on the Adjai, a distance of 16 miles. 



The greater portion of the field is enclosed between the Rivers 



Damuda and Adjai. South of the former a band of sedimentary rocks, 



6 miles wide, where broadest, stretches from the stream to the base of a 



range of small hills of metamorphic rocks. This range is by no means 



continuous, and in places recedes considerably from the boundary, 



being, as are most hills in the metamorphic rocks of Bengal, parallel 



to the strike of their foliation, which does not always exactly coincide 



with the direction of the fault bounding the field to the South, although 



there is a general parallelism: North of the Adjai the lowest portion of 



* In a direction somewhat transverse to the line of dip. 







