446 PROCEEDINGS OF THE ACADEMY OF [1897. 



The summit of the Siuiaia mountain known as " Koudriawy- 

 Kamen " is almost entirely formed of coarse grained diallage rock 

 containing a considerable quantity of olivine. From the summit of 

 Siniaia or Koudriawy-Kameu (crumpled stone) a splendid view is 

 obtained of the summits of the ranges. To the north appears Mt. 

 Katchkanar, and Mt. Blagodat, to the southeast is the village of 

 Laia and the works of Taguil, to the west is the Oural chain, here 

 running nearly north and south. 



Kouchwa and Mount Blagodat. — After a short run of nine wersts 

 north and northeast through gabbros, gneiss, and diabase, we reach 

 the station Kouchwa, on the last named formation, where the crown 

 owns works. The station is at the junction of the great and little 

 Kouchwa. The western part of the village extends over the large 

 low plain of these streams. Two wersts from the town is situated 

 Mount Blagodat. The constituent rock of this mountain, like that 

 of Wyssokaia, is an orthophyre without quartz, but with crystals of 

 Orthose and sometimes Plagioclase or Augite. All transitions from 

 coarse grained uralitic and augitic syenites to perfectly compact 

 orthose rocks resembling in external aspect the Swedish " Hallaflinta " 

 as observed by G. Rose. The rocks also approach the structure of 

 " Schlieren." The microstructure, the predominance of Feldspar in 

 the matrix and among the porphyritic elements, and finally the nota- 

 ble content of sodium bring the greater part of the rocks of Blagodat 

 near to the group of quartzless augitic porphyries called, after M. 

 Gumbel, ceratophyres. In Blagodat as in Wyssokaia the orotho- 

 phyres on the side of diminished mineral masses are enriched by 

 secondary Epidote, by Garnet, Analcime, Calcite, Chlorite and Mica, 

 and pass into epidote-garnetiferous and calcito-garnetiferous rocks- 

 The appearance of these rocks is connected with the disappearance 

 of the masses of Magnetite, as has been proven by the mining opera- 

 tions conducted at Blagodat. The magnetic ores of Blagodat appear 

 as red and as blue. The blue minerals abound in pellets of green 

 chlorite disseminated through the mass. Near the surface the Chlorite 

 is destroyed and the mineral becomes porous and easily fusible. Of 

 course as depth is increased the red mineral is more and more re- 

 placed by the blue. The deposits occur without definite boundaries, 

 over the entire east side of Blagodat to the summit wherever there 

 is orthophyre, but sometimes in the shape of tolerably regular veins, 

 and sometimes in nests and nodules. The veins gradually increase in 

 feldspar and pass insensibly into pure Orthose without Magnetite. 



