38 BLANFOED : GEOLOGY OP WESTERN SIND. 



although it is confined to Lower Sind, and although its base is only seen 

 in the Laki range, north of Ranikot, its upper strata occupy a consider- 

 able tract of country, about 26 miles long: from 

 Extent. 



north to south by about 12 in breadth, north-west 



of Kotri, and another even larger exposure, about 36 miles long, occurs, 



extending from north of Jhirak (Jhirk, Jhirruk, Jerruck or Jurruk) to 



Tatta. In the Laki range, the Ranikot beds are seen for about 35 miles, 



but the outcrop is never more than 2 or 3 miles broad, and one small 



inlier is exposed to the west of Ranikot. 



All the lower portion of the Ranikot group, including by far the 



greater portion of the beds, consists of soft sand- 

 Mineral character. 



stones, shales, and clays, often richly coloured and 



variegated with brown and red tints. Gypsum is of frequent occurrence ; 

 some of the shales are highly carbonaceous ; and in one instance a bed of 

 coal for lignite) nearly 6 feet thick was found, and a considerable quan- 

 tity of the mineral extracted. 1 The quality was, however, poor, and, from 

 the quantity of iron-pyrites present, the coal decomposed rapidly, and 

 was liable to spontaneous combustion when exposed, whilst the deposit 

 was found to be a small patch, not extending more than about 100 

 yards in any direction. Some of the more pyritous shale is used in the 

 manufacture of alum. The only fossils found in the lower portion of 

 the Ranikot group, with the exception of a few fragments of bone, 

 have been plants; some dicotyledonous leaves, hitherto not identified, 

 being the most important. All the Ranikot beds, except towards the 

 top of the group, have the appearance of being of fresh- water origin, 

 and are probably fluviatile. 



A variable portion of the group, however, towards the top, consists of 



highly fossiliferous marine limestones, often light 

 Fossilif erous beds. . .=, 



or dark-brown in colour, mterstratmed with sand- 

 stones, shales, clays, and ferruginous bands. These are the lowest beds 

 in Sind containing a distinctly tertiary marine fauna. The brown lime- 

 stones are well developed around Lainyan, Leilan or Lynyan, east of Band 



1 Mem., Geol. Sur., India, vi,, p. 13. 



( 38 ) 



