172 BLANFORD : GEOLOGY OF WESTERN SIND. 



wheat- land. As usual with all hot-springs in Sind, there is a consider- 

 able evolution of sulphuretted hydrogen. The temperature of this 

 spring is about 93 . 1 Some calcareous tufa occurs in the neighbourhood 

 of the spring, evidently deposited from the water, as is the case in 

 several other thermal springs in Sind. 



The Gaz and Dumbar range west of Tong is an anticlinal fold of 



the rocks, not rising to any great height. Khir- 

 Gaz and Dumbar range. 



thai* beds appear, and, in many parts ot tne range, 



form the highest portion ; but on the road from Tong to Baili (a police 

 post on the Kelat frontier, 6 or 7 miles west of Tong)', only the eastern 

 slope consists of Khirthar limestone, and horizontal Nari beds come in 

 at the crest of the range, whence they continue to the valley of the next 

 stream, a branch of the Baili Nai, where they roll over and dip west- 

 ward. Just before they roll over, a small fault is seen striking north- 

 ] O c -west, with a downthrow to the west. On its eastern side it brings 

 up some whitish limestone, which is seen in a low cliff north of the 

 road, and which appears to belong to the Nari group. 



North-east of Tong, there is a confused mass of hilly ground formed 

 of Khirthar limestone, and known as the Ban 

 (Bunn of inch and quarter inch maps) . It forms 

 a kind of irregular spur, projecting to the westward from the Khirthar 

 range, and it consists of Alveolina limestone. The beds on the Khirthar 

 ran^e dip steeply towards the Ban, and are faulted for some distance 

 against the latter, the bedding in which is very indistinct. 



There is a nearly horizontal outlier of Gaj beds to the south-east of 



Gaj beds south-east of Tong and south of the Ban, separated by an anti- 



Tong. clinal roll of Nari strata from the large Gaj tract 



1 I made it 90° ; Mr. Fedden 92-3° on one occasion, 93° on another. The spring 

 issues in an artificial pond about 20 feet in diameter, and 8 or 10 feet deep. It is difficult to 

 get at the actual source, and the temperature of the pond itself may vary somewhat with that 

 of the air. I think the temperature observed by Mr. Fedden is probably correct, as he had 

 a better thermometer ; but our two observations of the Laki spring, at which the spot 

 where the water issues is easily accessible, coincide perfectly, though taken in different 

 years. The hot-spring is the place marked on the map as Rath Nath. 

 ( 172 ) 



