: 
. 
+i lcs Sable 2 
eo sa ee Pe 9 
eee: 
Ss a eee, so ee TS TES A ee) ae en Me ema 
Ae mates eae 
Capt. Koschkull on the Caucasus. 337 
The total production of salt in the Caucasus is about 
24,000,000 kilograms of rock-salt, and 16,000,000 kilograms of 
lake-salt per annum. 
Aside from the salt lakes to which I have referred, there are 
others in the valley of the Kur and Araxes, of which the 
waters contain large quantities of sulphate of magnesia and 
carbonate of soda. 
Alum stone, which is very rich in alum, occurs on the 
northern slope of the Little Caucasus, and there is produced 
from it a yearly product of about 16,000 kilograms of alum. 
Of the minerals of the Tertiary formation, by far the most 
mportant are petroleum and asphaltum. All the accumula- 
tions of these substances are in the upper Tertiary strata, and 
are distributed geographically in several districts, of which the 
Most important are the extremities of the great Caucasian chain, 
which form the peninsulas of Taman and Abscheron; on the 
uks of the mountains on the north, in the valleys of the trib- 
Utaries of the Kuban, and of the river Saundga (Sundscha); 
on the southern slope, in the valleys of the Rion and Kur. 
_A considerable degree of system is noticeable in the distribu- 
tion of the springs of petroleum in each of these districts, and 
they are found to bear certain relations to the principal lines 
of upheaval which traverse them. Sometimes the springs issue 
m the summits of the anticlinal axes, and sometimes in par- 
allel lines along the slopes of the upturned strata. The petro- 
leum of the Caucasus consists of two well marked varieties; one, 
very fluid, of a light yellow color, found only on the peninsula 
of Abscheron; the other, dark brown in color, varying in density 
ftom that which is very thin to mineral tar and asphaltum. 
Carburetted hydrogen gas issues from all the petroleum springs, 
and is most abundant where the petroleum is lightest. 
eg oil springs of the Caucasus have been known and the 
collected from them for ages. Upon the peninsula of Ab- 
scheron, and on the banks of the Saundga and Kur, the petro- 
leum st 
the 
18 collected in pits of greater or less depth excavated in 
Sandy strata of the Tertiary age. The deepest of these pits 
nd from 70 to 100 feet from the urface, while the shallow- 
‘st are only two feet, : 
‘ In these pits the oil is accompanied by water, from which it 
wheeTterously separated by skimming. The instrument b 
h this 18 effected is a sack of green hide, the mouth encir- 
ky Y an iron ring, the sack being suspended by a cord. 
& general rule the wells are skimmed once a day. The 
nny ot petroleum obtained from the different pits is very 
arable, but is nearly constant for the same pit. The openmg 
AM. Joun, Scl.—Szconp Serres, Vou. XLVI, No. 138.—Nov., 1868. 
23 
