GEOGNOSY AND GEOLOGY. 14] 
granulite (a finely granular feldspar), occupying a similar relation to gneiss, 
occurs in a few localities, particularly in the ore mountains of Saxony. 
Less important subordinate members are schorl schist, graphite flag, 
micaceous iron schist, marble, and dolomite flag. Horn-slate occurs only in 
a few places, and clay shale connects the bottom rocks with the transition. 
Steatite furms isolated masses, especially in chlorite and tale slate, with 
which it is closely allied. Marble and dolomite, although subordinate, are 
yet very important and conspicuous members. They are either feebly 
distinct or closely connected together, and sometimes form entire mountains. 
They occur most generally in chlorite and tale slate, more rarely in clay 
shale. They have no distinct stratification, but a three-fold cleavage. 
The minerals composing the rock species occurring in the bottom series 
are not unfrequently separated, occasionally in fine ecrystallizations. Thus 
we find quartz and feldspar in gneiss, mica in gneiss, and mica schist, as 
also garnet, actinolite, tremolite, graphite, &c. 
Ore beds and veins occur here in the greatest profusion. The various 
associated mineral species are either separate or in combinations of various 
kinds. Beds are found of metallic oxydes, as of magnetic and specular 
iron ore, in Norway, Sweden, Siberia, North America, Brazil, and other 
places. There are also ores, as of iron and copper pyrites, zincblende, 
galena, mispickel, &c., this being particularly shown in gneiss, mica schist, 
and chlorite slate. 
The veins are. auriferous, in company with quartz and iron pyrites 
(in hornstone and gneiss); silver ores, as brittle silver glance, silver 
glance, antimonial silver, &c., with iron ores, as brown iron ore, specular 
iron, micaceous iron, &c. 
Veins of galena are generally accompanied by calc spar, brown spar, and 
quartz; veins of copper ores (consisting of copper pyrites, glance copper, 
and grey copper), by barytes; veins of cobalt and bismuth, by fluor spar, 
cale spar, and barytes. Furthermore, veins of antimonial glance and tin ore, 
with mispickel, molybdena, tungsten, scheelite, occur in connexion with 
fluor spar, apatite, chlorite, &c. Others, again, are met with, without any 
metallic minerals, as also some which are filled with abnormal masses. 
The bottom series is often of considerable extent, and of various external 
form, dependent upon the petrographical character of the members ; 
upon the influence of continually destructive forces ; upon the more or 
less compound character of the rocks; upon the stratification; and upon 
the varying situation above the level of the sea. 
Where the bottom series is not considerably elevated above the 
sea, it forms a hilly or mountainous country (as in Sweden, Finland, 
and North America), in which the waters have excavated deep channels, 
widening in places into lakes, as may be seen on a large scale in Finland. 
These excavations follow either the line of direction of the strata, or that of 
secondary cleavage. When the sea coast consists of strata of the bottom 
series, it is generally provided with deep indentations, forming the cliffs seen 
so conspicuously on the coasts of Sweden and Norway. With a greater 
elevation of the crystalline shale, its forms become more prominent: 
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