1897.] NATURAL SCIENCES OF PHILADELPHIA. 435 



On July 31 (August 12), 1897, we left Slatooust for Orjura, where 

 a halt was made, and a few hundred yards beyond which the conti- 

 nental divide forming the Eur-Asian frontier was reached and 

 passed, and the moderate descent on the Siberian side to Miass 

 at the foot of the Ilmen mountains begun. On the road thither, 

 and at the station Syrostan, a cutting exposes phyllites, a porous 

 talcose rock (listvenite) and serpentine. Further on schistose 

 rocks including metamorphosed porphyrites occur. The other sec- 

 ondary elements are Chlorite, Quartz, Calcite and Epidote. After 

 these, alluvium covers the surface to the station of Miass. Almost 

 the entire region between Syrostan and the Ilmen mountains is 

 auriferous, the central part of the auriferous belt containing the site 

 of the town of Miass. The gneiss on which the town of Miass is 

 built traversed within town limits by peridotite, in its western 

 part is replaced by siliceous schist (kieselschiefer) and phyllite. 

 The Miass placer situated only two kilometers from the station 

 is typical of the eastern Oural deposits of this character. The bed 

 above the auriferous gravel is about 2 to 4 m. thick, and consists of 

 turf, sand and clay. The auriferous bed itself consists of argilla- 

 ceous sand with many pebbles, and of gravel containing fragments 

 of gneiss, quartz and siliceous schist, of 0-7 m. in thickness. The 

 gold varies from 0-6 to 0-8 gram per tonne. This bed lies on gravel, 

 sand and clay, 2 m. thick. Borings show talcose and argillaceous 

 schists and serpentine below it. A little gold is found above these 

 rocks, but not in paying quantity. The placer which lies in the 

 ground immediately adjacent to the Miass river is about 1,380 m. 

 long by 320 broad. The terrace is the ancient bed of the river. 

 The gold is sought in the lowest points of the ancient and present 

 valleys. The peat or turf which lies upon this gravel is that which 

 extends over so large a part of the Siberian steppes and in which at 

 other places the remains of the mammoth and rhinoceros have been 

 found. The river is about 500 meters east of the present workings. 

 This placer was stated to be but 60 m. above sea level, and the mouth 

 of the Miass but 40 m. (?). 



The gravel is screened in a primitive circular rotating screen, of 

 which the axis is inclined, and is then passed over a table having 

 two amalgamated plates at the top and two at the bottom. The 

 shoot is about 5 feet wide and 35 feet long, with a fall of about 20°. 

 The coarse slimes are carried to the top of a scaffolding, while the 

 fine slimes are left. 



