400 
DESCENT OF THE RIVER KAKVA. 
one part 350 fathoms long by twenty wide, and has been worked to a depth of 
fifty fathoms, the adjacent limestone being chiefly converted into crystalline 
marble. In parts of the latter, however, which are less altered, we detected bands 
of black chett and other lithological characters so common to the palaeozoic rocks 
of the Ural; so that combined with fossiliferous proofs along the strike of the beds, 
to which we shall hereafter advert, we had no doubt that the real age of the lime- 
stone is Devonian. Some of the richest copper ore occurs in openings between 
the garnet rock and the limestone, or along their points of contact. In some parts 
it is enveloped by limestone, and in others by the garnet rock, which according to 
Helmersen is chiefly compact and tough, being crystalline only when in contact 
with the limestone 1 . The preceding diagram, taken from a coloured Russian plan 
of the works at Frelofski (one of the chief mines of Turyinsk), at seventy feet 
beneath the surface, will at once enable the reader to comprehend the relation of 
the garnet rock to the limestone rock, and how the intrusive rock has in parts not 
only cut off and isolated the limestone, but also the bands with garnets. 
All the undulating and lower country to the east of Bogoslofsk which we tra- 
versed, abounds, indeed, in a singular variety of mineral appearances. Thus a 
very few versts to the south only of the copper-mine of Turyinsk and Frelofski, 
are the noted gold mines of the Peshanka, which, formed out of the detritus of 
eruptive rocks which here and there rise to the surface, will be alluded to here- 
after, together with the auriferous phenomena. 
Descent of the river ICahva.— When isolated among the garnets, copper and gold 
of this tract, the warmest advocate for metamorphic agency may well have his 
misgivings as to such highly altered schists and limestones having ever been marine 
sediments charged with organic life. But if he be disposed to doubt that such 
changes have been accomplished, and the environs of Bogoslofsk on the west will 
not satisfy him (though fossils are also there to be found), we beg him to de- 
scend, as we did, the river Kakva from the station of Kakvinski, south of Bogos- 
lofsk, for a distance of fifteen or twenty versts. As this river flows in a gorge from 
west to east, and as all the strata of the region here strike north 15° east, and 
south 15° w r est, it is manifest that it thus offers a transverse section. Accompa- 
1 According to Colonel Helmersen, there are instances of the garnet rock branching off like trap 
dykes. The limestone is evidently the oldest rock : judging from the analogy of contiguous places, it was 
first invaded by the greenstone, and from the facts above cited, the greenstone porphyry was clearly 
the last formed rock. 
