1821.] Geological Society, ^9 



In a journey undertaken in the autumn of 1818 by Lieut. A. 

 Gerard, accompanied by his brother, for the purpose of approxi- 

 mating towards the extreme height of Manabarover by barome- 

 trical measurement of the bed of the Sutleig, a variety of 

 specimens illustrative of the geological structure of the lower 

 and middle valleys were collected, but in consequence of 

 the many difficulties which were encountered on the route, and 

 the accidents which happened to the travellers during their pro- 

 gress, this series has been rendered less perfect than it otherwise 

 would have been. 



The banks of the Sutleig, in the lower valley, at the elevation 

 of 2000 feet above the level of the sea, are composed of limestone 

 which is apparently primitive. The general inclination of the 

 strata is stated to be 10° or 15°, and the direction much diversi- 

 fied. At Jaure, on the northern bank, hot springs issue within. 

 two or three feet from the river. A thermometer plunged into 

 one of them rose to 130° of Fahrenheit ; while the temperature 

 of the river was 61°. The water has a strong sulphureous snjell, 

 and encrusts the pebbles among which it runs with a yellow 

 substance. Limestone seems the prevaihng rock on the hills 

 which bound the adjacent valleys. Among the specimens is a 

 stalactite from the roof of a cave near the top of the Carol moun- 

 tain, and about 6600 feet above the level of the sea. 



In crossing the Himalaya at the Bruauy pass, which is the 

 route of communication between the middle valley of the Sut- 

 leig and the valley of the Paber, and of which the extreme alti- 

 tude is 15,000 feet, mica slate, gneiss, and granite (some of the 

 specimens containing garnets, and others tourmaline), were 

 found ; and veins of quartz and mica, and quartz and hornblende, 

 are observable in the specimens which have been transmitted. 



The mean height of the Sutleig near to its influence with the 

 Bespa is 6,300 feet. The rocks which here form its banks are 

 inchned 25°— 30°, and dip eastward : they consist of granite, 

 gneiss, quartz rock, granular quartz; quartz, and mica, and gra- 

 nite with hornblende. Between this spot and Rispe, from 

 6500 to 9800 feet above the level of the sea, the rocks are 

 chiefly formed of a whitish crumbling granite. The Cailas, or 

 Raldang mountains on the south, an assemblage of pointed 

 peaks, covered with snow, and more than 20,000 feet in height, 

 are to all appearance composed of the same kind of rock. 



Overhanging the town of Marangis is a mountain of clay slate. 

 Upon it, at an elevation of 12,000 feet, heath, juniper, and 

 gooseberry bushes, are growing. In advancing to the Tun ^rang 

 pass, which is 13,740 feet above the sea, rocks formed chiefly 

 of compact quartz, with chlorite, were observed. The pass 

 itself exhibited clay slate, with pyrites and globular mica. 



A few miles further on, granite, gneiss, mica slate, quartz and 

 mica, actinolite, with quartz and garnets, pyrites in quartz, a 

 bluish-grey limestone, with white veins and calcareous tufa, were 



