148 
SECTIONS ON THE WEST FLANK OF THE SOUTH URAL. 
eastwards at 20°. The annexed woodcut will convey a tolerably correct idea of 
the transverse section across this valley. 
23 . 
(The spectator is looking southwards.) W.N.W. 
E.S.E. Grebeni. Palatki. 
Limestone. Gravel. Limestone covered by sands* marls, &c 
The best beds of this limestone are so copiously charged with broken shells, and 
when worked assume so white a colour, that they somewhat resemble the calcaire 
grossier of Paris, and, like that stone, they are easily chiselled and ring under the 
hammer. The fossils of Grebeni are Productus Canncrini (nob.), Orthis Wangen- 
heimi (nob.), Avicula Kazunensis (nob.), Modiola Pallasii? (nob.), Retepora flus- 
tracea (Phil.), &c. 
In several places along the west flank of the South Ural we met with a succes- 
sion similar to that which is given in the above woodcut. Thus at Visilki, two 
versts north of Gorodok-Sakmarsk, limestone with the same fossils as at Grebeni, 
and in which the Retepora jlustracea ? abounds, dips at 20° to the west and by north, 
under grey grits and sandstone, the lowest beds being calcareous and containing 
shells ( Productus , &c.). In following this section a little to the west, the next 
succeeding beds are found to be composed of red siliceous conglomerate, slightly 
dipping off at first, but soon becoming horizontal, in which copper ore being 
largely disseminated, has given rise to the mines of Kargalinsk. As in other 
places where copper ore abounds, fossil trees and plants are also of frequent occur- 
rence, and although at the time of our visit we were not so fortunate as to procure 
them, this spot has also afforded many remains of fishes (Paleeonisci) , with bones of 
Saurians, &c. To the north of Sakmarsk, at about twenty-five versts towards 
Yemangulova, a section exposes a similar succession from an inferior limestone 
through grey grits into red overlying ground, and here the direction is transverse 
to the prevalent strike, and instead of dipping to the east or west, following the 
line of the chief anticlinal which is parallel to the Ural, the strata plunge 20° to 
the north, exhibiting a fracture, at right angles to the main elevation, and in the 
line by which the river Sakmarka escapes from the mountains (see Map). At 
Yemangulova and to the west of that village, a whitish fossiliferous limestone 
occurs, which is capped by sandstone and layers of grey-coloured limestone, the 
whole dipping about 12° north-east. 
