440 PROCEEDINGS OF THE ACADEMY OF [1897. 



and yellow post-tertiary clays covered by tschernozem. From the 

 7th to the 52d werst from Tcheliabinsk the clays cover the oldest 

 rocks almost everywhere. It is only in rare instances that one 

 observes the islets of tertiary conglomerates and sandstones, which 

 have escaped erosion, appearing above the surface (12 to 43 wersts) 

 and siliceous clay with Glauconite (44 wersts), a Kaolin produced 

 by the alteration of a subjacent granite, a diorite (?) (32 wersts), a 

 dioritic porphyrite (Lake Kissiagutch) and a Labradorite porphyry 

 (46 wersts). From the 50th werst such outcrops become more 

 frequent. First come aphanitic and other massive altered and 

 clastic rocks. At the 64th werst an uralitic porphyrite occurs, 

 becoming an uralitic schist ; then serpentine and chloritic schist, and 

 finally gneiss and granite alternating with chloritic and uralitic 

 schists, which predominate further on, and upon which are built the 

 Kytchtym works. The gneisses are often biotitic, often amphibolic, 

 and often garnetiferous. The strike of all the crystalline rocks is 

 nearly that of the meridian. (L. G., V, p. 33.) 



August 3 (15) the party of excursionists left the station of Kytch- 

 tym in droschkes and drove around lakes Kytchtym and Sougomak 

 to the base of the Sougomak mountain. Between Kytchtym and 

 Sougomak mountain only biotitic and amphhibolic gneiss were ob- 

 served, cut by peridotit'es more or less serpentinized on the north 

 of the lake. At the same place appear in irregular prominences 

 masses of granitic and syenitic character. The mountain is partly 

 schistose, and contains limestone with a grotto among the gneiss, 

 but in the main it is composed of massive, extremely tough serpen- 

 tine with antigorite. From the summit of the mountain a magnificent 

 view is obtained of the Siberian plain and of the mountainous part 

 of the Ourals. 



The ascent was along the border of Kytchtym lake and through 

 the town of that name around lake Sougomak and up to the 

 arrete over a grassy slope of easy grade. Hence, the ascent was 

 completed by a circuitous path over a species of col to the 

 shoulder beyond, where a path led up to the summit. On the top 

 was a fine compact rock determined to be serpentine. The view 

 from here of the Siberian lakes and steppes was very extensive. To 

 the west the Ilmen mountains were in sight and also Mt. Yourma, 

 which Humboldt erroneously supposed to be the nucleus of three 

 independent mountain chains. 



