HILLS NEAR SUKKUR AND ROHRI. 103 



ing them decomposes easily, and the rises composed of it weather into flat- 

 topped craggy hummocks. The appearance of these is so characteristic, 

 that hills formed of this bed may easily be recognized by their form. 

 Such are seen at Sapoinwali Tekri, and again 12 miles farther south 

 at Sahibneh, south-by-west of Janoji, and close to the frontier of 

 Khairpur. At the latter place some small nodules of ironstone occur in 

 the limestone, and are found scattered about the surface. They are not 

 in sufficient quantity to have any value. 



Below this highly fossiliferous nummulitie limestone there is found, 



throughout the Sukkur and Rohri Hills, a thick- 

 Limestone with flints. r> ™ n o ^ ^ 

 ness ot, perhaps, 200 to 300 feet ot very hard 



limestone, generally more or less yellow in colour, of fine texture, but 



not solid as a mass, being much fissured and cracked. As a rule, this 



bed is not fossiliferous, but sometimes it contains Alveolina and small num- 



mulites in considerable quantities, especially in its upper portion. The 



most remarkable character of this bed, however, especially towards the 



base, is the occurrence of large masses of flint, many of which precisely 



resemble, in every respect, those of the English chalk. Some of the 



nodules at Sukkur exceed a foot in diameter. These flints contain 



sponges and less frequently Foraminifera. 



The hard limestone just described forms the upper part of the hills, 

 both at Sukkur and at Rohri, and at both places the bed includes, about 

 30 feet above its base, a layer, about a foot thick, of yellow marl, or 

 argillaceous limestone. In this bed at Rohri, close to the Deputy 

 Collector's bungalow, Echinolampas sindensis occurs in abundance. 



The same limestone with flints occupies the surface throughout the 

 greater part of the range south of Rohri, the higher beds being only seen, 

 as already mentioned, towards the eastern edge of the range, whilst those 

 lower in the series are only exposed on the western scarp. The surface 

 of the limestone consists in general of a series of low slopes, correspond- 

 ing in direction to the dip of the rock. The flints weather out and cover 

 the surface throughout a large area ; cores and the flakes split from them 

 being scattered about in abundance in some places. 



( 103 ) 



