220 Capt. Koschkull on the Caucasus, 
The sedimentary strata which covers the igneous and ¢ 
talline rocks, and which enter so largely into the compositionof — 
the mountain chains of the Caucasian isthmus, belong to the 
Jurassic and Cretaceous formation 
The Tertiary strata are spread over the plains border 
Great Caucasian chain, both on the north and south, ining 6 
traversed by the rivers Terek and Kuban on the. north, the 
Rion, Kur and Araxes on the south. 
rom the northwestern extremity of the main chain of the 
Caucasus, as far east as Mt. Elbruz, the portion of the stratified 
rocks is quite regular. They here lie in a series of parallel folds, — 
which have a northeasterly trend. It results from the regu- — 
larity in the position of the strata, that on going from the main 
chain toward the north, each new ‘element in the geological s 
ries represents @ more "recent, while on going south from the 
axis, more and more ancient strata are success : 
South and east of Mt. Elbruz, the saatie of the oa fet : 
strata become very complicated and obscure, from the intersec- 
tion of various lines of elevation. In Daghestan and the Little 
Caucasus, this a poem in the position of the sedimentary 
rocks is particularly mar 
In the Tertiary diiselts, the Eocene and Miocene beds e&- en 
hibit some of the undulations which characterize the um x 
ing rocks ; but the Pliocene and Arabo-Caspian deposits ae . 
eat always quite horizontal. 
The line of contact of the amphibolic and jee 
with the other igneous rocks, as well as with the se 
strata, is almost always, throughout the Caucasus, 
the presence of metallic ores. As regards the num 
eral deposits known and worked, the Little Caucasus shot 
given the first place. 
Argentiferous galena has been found in nearl 
tainous portions of the Caucasian Isthmus. Th es 
of these districts, warlike in character and aa to. 
chase, have always needed lead with which to form their © 
lets, and from this cause the veins of this mineral have 
only been sought and discovered, but in many places they fi 
been extensively worked. To obtain metallic lead from 
ore, this latter is melted in small furnaces, in @ Very rude 
the silver which it contains bein neglec ted. - 
€ most important veins of ead are found on the nor a 
slope of the main chain of the Caucasus, between ¥y paksal 
and Mt. , in the valleys of the rivers Ard ane ai, 
‘nibutares of the Terek. Here the galena, is accomp* 
blende, copper and iron Eyres, in veins cutting granlt 
and metamorphic slates 
