SECOND YARKAND MISSION. 



parallel secondary chain. Between the two the palaeozoic rocks rise to a considerable elevation, forming 1 

 synclinal and longitudinal valleys. We shall follow the section to the north-east, from the foot of the principal 

 ridge, according to SevertzofFs latest accounts, and begin at the Naryn River, the valley of which is bounded 

 on the south by an outer range of the Thian Shan, the Chakir-tau. This consists of granite and mica schist, 

 the opposite slope of the valley being entirely composed of contorted clay -slate, which locally, overlaid by dark 

 violet porphyry conglomerate, extends to the north-west to the top of the Sari-tau, in which, at the pass of 

 Barskoum, syenite is exposed. 



" Proceeding from this pass towards Lake Issik diorite and serpentine are first seen ; then mountain 

 limestone, which forms a synclinal. This synclinal coincides with the longitudinal valley separating the Sari-tau 

 from the next range to the north, the Terskei- Alatau, and this latter corresponds to the Sari-tau ridge 

 precisely, so that, on the north side of the intervening valley, first mountain limestone with the slope reversed, 

 then diorite, and finally syenite, are met with. Below, on the shores of Issik-kul, sandstone is found, which 

 may be compared with the carboniferous strata of the Kara-tau. * At the eastern end of Issik-kul the little 

 range of Kisil-kija 2 consists of red argillaceous sandstone; this range lies nearly in the direction of the 

 greatest (longitudinal) diameter of the lake itself, and in the line of strike of the Rothliegende at the western 

 end of the lake, in the gorge of the Boam stream and on the northern slopes of the Khighiz Alatau. 3 

 Proceeding over the Santash pass into the region of the Trans-lli-Alatau, this is found to consist of granite 

 intersected by two or more bands of limestone standing at high angles or bent into trough-shaped curves ; one 

 of these bands forming the ridge between the rivers Chilik and Chanishk. 



" Finally, the granite northern slopes of the Trans-Hi- Alatau, as already stated, are terminated, towards the 

 north, by a long but rather low chain of hills which consist of porphyry."] 



1 North of Chemkend and Tashkend. | 3 Tasrna mountains on some maps. 



3 Now called on many maps Alexandrovski range. 



