416 
ERUPTIVE ROCKS AND DISLOCATIONS OF THE TIMAN. 
the rock is more or less basaltic, of a dark colour, compact structure, and con- 
choidal fracture, with rare grains of a black vitreous mineral, and little crystals 
of Stilbite. Numerous veins and dykes of chalcedony traverse it, and give rise 
to druses of amethyst. Occasionally the structure is prismatic, and at other places 
the mass is regularly stratified in thick beds traversed by joints. This eruptive 
rock is singularly well laid open in the deep gorge of the river Bielaya, where it 
occupies vertical cliffs, of 300 feet in height. 
The carboniferous grit, resting against the western side of these elevations at 
different levels, is, as well as the carboniferous limestone, inclined towards the 
trap, and might therefore at first sight seem to indicate that though the basaltic 
mass has unquestionably cut through, and perhaps raised up these sedimentary 
rocks, it has not given to them their present general inclination. But numerous 
examples in the Ural Mountains and other parts of the world, where the sedimen- 
tary strata dip inwards towards the eruptive ridges, and not away from them, 
would rather lead us to infer, that in undergoing a great vibratory and undulatory 
movement, the ends of the sedimentary strata adjacent to the eruptive masses 
have been let down by a subsidence into cavities occasioned by the evolution of 
much igneous matter, whilst their other side has been tilted up. 
Whatever theoretical explanation maybe attempted, it is certain, that these car- 
boniferous strata are highly inclined and dismembered in the vicinity of the basal- 
tic rocks, and this suffices for our purpose. The granitic axis of this range seems, 
indeed, to have been constituted at a much more ancient period, for it is flanked 
on the east by highly inclined slaty schists. These schists rise, in fact, into little 
discontinuous crests all along the chain, even where the granite is no longer seen 
at the surface, and everywhere they are very highly inclined and uniformly 
plunge to the north-east. The palaeozoic rocks (if this name be restricted to those 
in which we actually discovered organic remains) are unconformable to these 
older schists, being, indeed, very feebly inclined, and usually to the east. For all 
that we know, the eruption of the granite of this region may have either been 
confined to a period anterior to animal life ; or the ancient schists may represent 
some portion of the Lower Silurian sediments, in which few or no creatures were 
entombed. But we will not attempt to reason further upon such negative evi- 
dence, nor do we even desire to imply, that the most ancient schists of the Timan 
may not be of the same age as the large mass of the old gneissose and slaty rocks 
of Scandinavia. At all events, if referred to the palteozoic age, it is almost certain 
