140 GEOLOGY. 



tops, from 20 to 400 feet above the plain. The largest ono ascended 

 was about 100 feet wide at top, and resembled a cup filled with liquid 

 mud, which occasionally overiiowed. Sometimes an ebullition of gas 

 took place, but there was no heat evolved. The mud (analyzed by Mr. 

 Ward) consists mainly of carbonate of lime with some quartz-gand. 

 The water contains common salt and a little sulphate of lime. These 

 craters are most active at spring-tides. The author thinks they may 

 be caused by hydrostatic pressure, and unconnected with volcanic action, 

 of which this coast affords no trace. There is reason to believe that 

 similar craters exist under the sea, but near the shore. The clay for- 

 mation forms the bed of the sea for some miles from shore, the de^^th 

 of water increasing gradually to about 30 fathoms, and then suddenly 

 to 300 or 400 fathoms. This precipitous edge the author believes to 

 have once been a sea-cliff. It is probable that the land afterwards 

 sank below its present level ; for lithodomous perforations are found in 

 the clay considerably above the sea-level. W. T. 



Stipfe, Lieut. A. "W. The Island of Hormuz (Ormuz). Geogr. Mag. 

 vol. i. pp. 12-17, map. 



The greater part of the island is probably of volcanic origin, consist- 

 ing chiefly of rock-salt ; and there are hills of a grey trachytic rock. 

 At the S.E. corner there are some stratified rocks. 



Stoliczka, Dr. F. Structure of the Hill-ranges between the Indus 

 vaUey in Ladak and Shah-i-Dula. Eec. Geol. Surv. Ind. vol. vii. 

 pt. 1, pp. 12-15. , 



South of the Indus near Leh are Eocene sandstones and shales ; north 

 of the Indus is a ridge of syenitic gneiss ; this passes (northwards) into 

 syenite and chlorite schist, with a more massive chloritic rock ; so to 

 the Changchenmo valley. These schistose and chloritic rocks the author 

 considers to represent the Silurian formation. North of that valley are 

 dark shales and sandstones, which extend to the boundary of Lingzi- 

 thang, which the author thinks to be Carboniferous. In places along 

 the bank of the Changchenmo river this is overlain by Triassic lime- 

 stone, also found in the hills 'N. of Lingzithang and in the upper Kara- 

 kash valley. At Kizil-jilga is dark slate, which continues down the 

 Karakash river as far as the bend; these slates are probably Silurian, 

 corresponding to the schists on the S. side of the ranges. P. D. 



Geological Notes on the Eouto traversed by the Yarkund 



Embassy from Shahidulla to Yarkund and Kashgar. Eec. Geol. 



Surv. Ind. vol. vii. pt. 2, pp. 49-51 ; and Quart. Journ. Geol. See. 



vol. XXX. pp. 571-573. 

 Metamorphic rocks (gneiss alid schist) occur from the Karakash river 

 to near lam, north of the Sanju Pass ; then black slates rest uncon- 

 formably on the schists, and are overlain by grey sandstone and con- 

 glomerate. By Kiwaz there is conglomerate resting on Carboniferous 

 Limestone, which again rests on chloritic schist. At Sanju red sand- 

 stone is overlain by calcareous sandstone and marl (Middle Cretaceous). 



