NERCHINSK

See also:

• MINING

MINING

See also:

• DISTRICT

DISTRICT  extends over an area of 29,450 sq. m., and includes all the silver-mines and gold-fields between the Shilka and the Argun, together with a few on the left bank of the Shilka . It is traversed by several parallel chains of mountains which rise to 4500 ft., and are intersected by a complicated system of deep, narrow valleys, densely wooded, with a few expansions along the larger rivers, where the inhabitants with difficulty raise some rye and wheat . The population (75,625 in 1897) consists of Russians, Buryats and Tunguses . Included in this number were some 2300 convicts . The mountains, so far as they have been geologically explored, consist of crystalline slates and limestones—probably Upper Silurian and Devonian—interspersed with granite, syenite and diorite; they contain rich ores of silver, lead, tin and iron, while the diluvial and alluvial valley formations contain productive auriferous sands . The Nerchinsk silver mines began to be worked in 1704, but during the first half of the 18th century their yearly production did not exceed 8400 oz., and the total amount for the first 15o years (1704–1854) amounted to 11,540,000 oz . The lead was mostly neglected on account of the difficulties of transport, but its production is at present on the increase . Gold was first discovered in 1830, and between 1833 and 1855 260,000 oz. of gold dust were obtained . In 1864 a large number of auriferous deposits were discovered . Until 1863 all the labour was performed by serfs, the property of the emperor, and by convicts, numbering usually nearly four thousand .