492 Notices and Extracts from the Minutes of the Geological Society. 



of three miles by the detritus carried down by the river, with regard to which 

 it may be stated that the base of the triangle of the delta is above 125 miles. 



After mentioning a range of hills called the Hala Mountains (about 2000 

 feet high), which extends in a northerly direction from the sea-shore west- 

 ward of the mouths of the Indus, and terminates to the north-west of Cabool 

 in the Hindoo Caucasus, and which consists in part of compact nummulitic 

 limestone, the author proceeds to describe the principal geological features 

 which he observed on the banks of this great river. The town of Hydrabad, 

 he states, is built on a finely grained shelly limestone. At Schwan, in lat. 

 26° 22', and at Curachee, are hot wells ; and the island of Bukhur, in lat. 

 27° 42', consists entirely of flint. On the eastern bank of the river, opposite 

 this island, is a precipice of flint, 40 feet high, on which the village of Roree 

 is built. In lat. 28° 55' the rivers of the Punjab fall into the Indus. Still 

 higher up, in lat. 33°, at Kara Bagh, the river cuts through a range of hills, 

 described by Mr. Elphinstone as the salt range. The salt is found in layers 

 of about a foot in thickness, separated from each other by thin strata of clay. 

 With the exception of this range of hills, which is estimated to be about 1800 

 feet above the level of the sea, the district of the Punjab is uniformly flat; 

 but the hilly district is intersected by numerous defiles, presenting vertical 

 strata, which terminate in peaked points. Between the river Sutlege and 

 Lahore the country consists of indurated clay, sometimes gravelly. 



At Attoch, much higher up, the rocks by which the Indus is confined, con- 

 sist of a dark-coloured micaceous slate, which is said to extend to the south- 

 ward, until it meets the salt range above mentioned. Near this place gold is 

 washed out of the sand of the river. 



At Lahore, in February 1832, the author experienced a very violent shock 

 of an earthquake. Several valleys were choked up by the masses of rock 

 thrown down from the overhanging precipices, and a great part of the popu- 

 lation of Badakhshan was destroyed. In crossing the Punjab the author 

 observed that several buildings of the Mogul Emperors were decaying from 

 the foundations, and were encrusted with an efflorescence of nitre. Pro- 

 ceeding to the westward from the Indus, he found bituminous coal at Cohat, 

 and that the salt range above mentioned extended across the country into this 

 district. The river of Cabool flows through a very narrow defile, the rocks 

 of which rise to a height of 2000 feet, and consist of sandstone, quartz rock, 

 and mica schist, the strata of the latter being vertical. Cabool is situated 

 6600 feet above the sea*, and the source of the river Cabool 8600 feet, where 



* The heights rnentioned in the Memoir were determined from the boihng-point of water, COO 

 feet being allowed for each degree. 



