GEOLOGICAL FORMATIONS. 55 



represented by a thin band containing one of the characteristic fossils. 

 Ostrea multicostata, at the base of the Manchhar group. There is, 

 Distribution in Lower however, a very large area of Gaj beds north 

 d- and north-east of Karachi, and the appear- 



ance of the formation here is somewhat different from what it is in the 

 Khirthar range, for the greater portion of the group consists of 

 pale-coloured limestones, almost horizontal, or dipping at very low 

 angles, and to the east of the Habb valley forming plateaus 400 

 or 500 feet high, bounded by steep scarps, which rise from the 

 low ground of the soft Nari sandstones. A low range of hills, 

 formed of Gaj beds, extends to the south-west, past the hot-spring 

 at Mugger or Mangah Peer, to the end of the promontory known 

 as Cape Monse, west of Karachi, and the same beds form the low 

 hills east and north-east of the town, and furnish the" materials of which 

 the houses in Karachi are mostly built. A small island called Churna, 

 in the sea, west of Cape Monze, also consist of Gaj rocks. To the 

 northward the Gaj area of Lower Sind extends with very irregular out- 

 line to the neighbourhood of Tong and Karchat, almost due west of 

 Hala, and there are several outliers farther north, connecting the south- 

 ern portion of the group with the typical outcrop in the Khirthar 

 range. East of Karachi, also, Gaj beds extend in the direction of 

 Tatta, until they disappear with the other tertiary rocks beneath the 

 alluvium of the Indus. The Gaj group of Sind appears to be repre- 

 sented in Cutch by a highly fossiliferous belt, containing most of the 

 typical mollusca, echinoderms, &c. It is quite possible that the present 

 group, as well as the Nari, never was deposited throughout the greater 

 part of the country east of the Laki range. 



It has been already stated that the Gaj beds, throughout the greater 

 Relations of Gaj group portion of the Khirthar range, rest conform- 

 to Nan. a k]y. U p 0n the Nari group, although there 

 is a change in mineral character, and that in Lower Sind the passage 

 from one group into the other is gradual, calcareous bands with Gaj 

 fossils, such as Ostrea muliicoslata and Peden snbcorneus, being found 



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