EASTEKN ORIGINAL SIBERIA. 35 



Soniowhat more complex is the coustriietion of the Sayan in the south-eastern portion of the 

 Irkutsk government, beginning with its most elevated mass situated between the head waters 

 of the Beikem and Ulukem, on the one hand, and tliose of the ji'ft tributaries of the Angara, 

 Oka, Belaia and Irkut, on the other. Here this range shows a tendency to break up 

 into chains, or ridges, parallel to each other and separated by longitudinal valleys, here 

 united by projections of the main ci'est, there cut asunder by transverse dales through which 

 the nunii'rous rivers struggle out the slope of Eastern Siberia and form the left tributaries 

 of the Angara. 



In the midst of the main crest of the Sayan, at the MMilh-eastern corner of the Irkutsk 

 government, the highest mountain mass of the Sayan range lifts itself far above the limits of 

 eternal snow in its highest point, the Munku-Sardyk peak, lying on the Chinese frontier, 

 reaching an elevation of 11,430 feet above the sea level. This mountain, as also some other sum- 

 mits in its neighbourhood sitiiateil on the projectiDns of the Sayan range crossing into Russian 

 territory and called hi're not belki as in the Altai, but «golets>>, feeds more or less consider- 

 able glaciers and ice fields, occurring on a somewhat greater scale in this part of the Sayan 

 than in the Katun Pillars of the Altai. A little lower than those golets rise, parallel to the 

 main crest of the Sayan, the forward ridges, among which the most remarkable is the Tuuka 

 range lying close to Irkutsk. In another of these ridges, at a distance cd' 120 versts to the 

 south-west of Irkutsk, is the mountain Khamar-Daban, reaching an elevation of 8,940 feet 

 above the sea level. In connection with this Khamar-Daban are two ridges stretching almost 

 parallel to each other in a north-easterly dinM/tion. In the wide and very long valley separat- 

 ing them, is situated one of the largest lakes on the world's surface, Baikal, whose area of 640 

 square geographical miles is equal to the extent of the Kingdom of Holland with the Grand 

 Duchy of Luxemburg: its breadth exceeds the huigth (d' Lake Geneva, and its length 

 is 670 versts. Lake Baikal is fed mainly by rivers flowing over the Transbaikal region, the 

 Upper Angara, Barguzin and Selenga. Its outlet is the colossal right branch of the vast 

 river system of Eastern Siberia, the Angara, bursting first through the tlefih^ of the Baikal 

 range, confining the lake on the north-west, and afterwards intersecting the extremities of sev- 

 eral of the spurs of the Sayan extending far over its slo|).>. It is at these points of inter- 

 section that the Angara forms its celebrated rapids. 



All the cliief summits of the Sayan range, and even of its oil'spurs, consist of crystalline 

 rocks, granites, sienites, more seldom diorites, porphyrirs and diabases, and also of gneiss and 

 crystalline schists. In the eastern part of the Sayan range, and also in the low ridges intei"secting 

 the Eastern Siberian plain between the Angara and thePodkamennaia Tunguzka,real plutonic rocks 

 are met with, sucii as bazalts, dolerites and even lavas, fiom the long since extinct volcanoes, with 

 vulcanic tufas, oljsidian and pumice. The sedimentary rocks upon the slopes of the Sayan 

 ridg(^s consist of sandstones, schists ami limesloiK^ b(diniging to the paleozoic formations, Si- 

 lurian, devoiuan and I'arbonil'erous, but furtlirr to tin' north in the di'umled |>ai'ts (d the low 

 ridges, intersecting the Eastern Siberia plain, sei'ondary I'oruiations also ari' met with, such as 

 triassic and Jurassic. 



The mineral resourc(\s of Eastern Siberia are considerable. I'pou thi' inuthcru aeclivity or 

 the Sayan in the Yi'insseisk goveiiiinont, mines of argentiferous leail and coppei- aie found, and 



