SOUTH-WESTERN PORTION OF KARACHI COLLECTORA.TE. 183 



distance above the base of the Gaj beds, there is a second coral bed rest- 

 ing upon grey sandstones precisely like those of the Nari group. 



The Gaj beds are fairly seen in the ridges traversed by the road from 

 Karachi to Mugger Peer, and several of the usual fossils occur. 



West of Mugger Peer the boundary of the Nari and Gaj beds is 

 difficult to determine exactly, the rocks being much covered by alluvium. 



The marine bed, with Orbitoides, Clypeaster, and Pest en subcomeus, can 

 South-west of Mugger De traced here and there just below the top of the 

 Peer- Nari group ; and a hard band of Orbitoides lime- 



stone, perhaps the same as that seen in so many places higher up the 

 Habb valley, crops out at a low horizon, and forms a well marked ridge, 

 extending for many miles ; but the actual boundary is ill seen until close 

 to the telegraph line from Karachi to the Mekran Coast. Here the 

 lowest Gaj beds begin to form a well marked ridge, which continues to 

 Cape Monze, the highest portions being known as Lai Bakkar and Haji 

 Zara. In this range there are three breaks, caused by faults, all having 

 a general west-north-west and east-south-east direction, two with a down- 

 throw to the south and one to the north. All these breaks are shown on 

 the Revenue Survey Map, which is here and throughout the neighbour- 

 hood of Karachi excellent. North-west of the Gaj ridge, the Nari beds 

 are fairly seen for a short distance, but the Habb valley is a broad sandy 

 plain, with only a few isolated outcrops of the harder Nari beds forming 

 long low ranges. 



About Haji Zara a hard band of Orbitoides limestone occurs close to 



Orbitoides bed at Haji the top of the Nari group. Besides Orbitoides, it 



contains other Foraminifera, some looking very 



like small nummulites. They are, however, not very well preserved, and 



the identification is doubtful; but if they are really nummulites, the 



horizon is the highest at which the genus has been observed in Sind. 



Near Cape Monze (Ras Muari) there is an anticlinal roll of the strata, 



and the Gaj ridge, after running down the east 

 Cape Monze. 



Side of the promontory, turns round at the Cape and 



runs up the west side as far as the mouth of the Habb river. The rocks 



( 183 ) 



