SOUTH-WESTERN PORTION OF KARACHI COLLECTORATE. 163 



with bands of yellow limestone, more or less argillaceous or sandy, form- 

 Khirthar group east of ing the passage beds to the Ranikot group. The 

 thickness of the Khirthar group here can scarcely 

 exceed 500 or 600 feet, and may be less in places. 



Near the base of the Nari group around Jungshahi is a hard brown- 

 Nari beds near Jung- ish-yellow calcareous sandstone with casts of Orbi- 

 toides. This bed, which is very conspicuous and 

 easily recognized, has been much quarried in the neighbourhood of the 

 railway to supply building material. The lowest bed of the group, 

 underlying the hard sandstone, is a softer sandstone, calcareous or argil- 

 laceous, with numerous Orbitoides. These two beds form the ' Orbitoides 

 sandstone ' already referred to. Upon them are other sandstone beds of 

 varying texture and colour, with shales and some clays. The rocks just 

 described occupy the country around Jungshahi and immediately north 

 of the station. To the westward there is an ascending section, the 

 Nari group becomes much thicker, and higher beds, chiefly sandstones 

 of various kinds, usually shaly, but sometimes calcareous or gritty, 

 make their appearance. Between 4 and 5 miles west of Jungshahi 

 gritty buff limestone appears with ill marked Foraminifera, some of 

 them small, others very possibly Orbitoides, but too ill-preserved for 

 identification. This bed rests on whitish sandstone. A somewhat 

 similar bed is found in the middle of the Nari beds of the Habb 

 valley to the westward, but there shells of Orbitoides are abundant and 

 well preserved. 



The base of the Gaj beds west of Jungshahi is at a distance of 

 Gaj beds west of Jung- nearly 8 miles along the railway, in the scarp west 

 snalu - of the Ranpetiani stream. The lowest Gaj consist 



of rubbly calcareous beds with sandstones, and buff and ferruginous sands, 

 abounding in Breynia carinata, Pecten subcomeus, Ostrea multicostata, 

 and numerous casts of Voluta, Natica, Turritella, &c, besides club- 

 shaped spines of Cidaris, swollen near the base, attenuate towards the 

 apex and ribbed. 



Here, then, only a few miles west of Jungshahi, the normal 



( ]fi« ) 



