CRETACEOUS. 103 



which renders their boundary most difficult, and sometimes impossible 

 to follow in close detail, throug-h that wild, rugged, and frequently preci- 

 pitous country. 



The whole group commences in cliffs west of Jalar lake, reach- 

 ing along the southern escarpment of the Son- 

 Commencement. 



Sakesar basin, where it is interrupted by fanlts, 



but it reappears in the fine cliffs south of Sakesar summit, and it is also 



exposed by erosion on the northern slopes of that mountain. From 



Sakesar north-westwards it extends with some interruptions along the 



narrow part of the range and through the Tredian hills to Khyrabad. 



The thickness of the formation may be estimated 

 Thickness. 



at five hundred feet where fully developed. 



Cretaceous. 



No. 10. — The Jurassic rocks, as has been just now stated, pass up 



with an apparent lithological transition into the 

 Passage beds to west. . 



nummulitic series m the west of the district; 



some of the intervening bands just at the base of the eocene, however, 

 contain fossils of a different aspect from those of the immediately over- 

 lying rocks. Dr. Waagen remarked a typical 

 Eonca type of fossils. 



resemblance between these fossils of the lower 



beds and those of the Ronca or Italian eocene.^ They have only been 

 observed in the Bakh ravine southwards from Namal, and they may be 

 taken to indicate the limit here between the mesozoic and tertiary epochs. 



In the eastern parts of the district, however, there occurs a very 



considerable group of sandstones, of dark greenish. 

 Eastern representatives. 



greyish, white-and-yellow striped, yellow-and-grey 



spotted, or olive or whitish colour, in the upper part of which coaly 



seams occur with some shaly bands, while in the lower part are strong 



bands of conglomerate, or thick, dark, trappean-looking shales filled with 



* From information given by Dr. Waagen. 



( 103 ) 



