SILYEE, LEAD AND COPPER. 165 



aud the Gourevsk in 1816. Nearly all the works in the Altai are silver smelting works, the 

 only exceptions being the Tomsk and Gourevsk iron works and the Souzounsk works which 

 smelt copper as well as silver. According to their geographical position all the ore deposits 

 of the Altai mining region may be divided into two independent groups. The first of these 

 groups, the so-called. Zmeinogorsk region, lies in the southern portion of the Altai region, 

 in the systems of the rivers Obi and Irtysh; and the second or Salairsk region lies at the 

 north-eastern extremity of the Altai region in the system of the river Toma. The most im- 

 portant difference in the conditions of these two groups is that the works of Zmeinogoi'sk 

 region exclusively employ charcoal fuel, while those of the Salairsk region being in the 

 near neighbourhood of the Kouznetsk coal basin, work with mineral fuel. 



The mountains which contain the ore deposits in the Zmeinogorsk region belong to the 

 branches of the Sayansk mountains; while those in the Salairsk region belong to the branches 

 of the Altai mountains. They generally have the appearance of rounded volcanoes, without 

 any rocky peaks. As a rule the height of these mountains does not exceed 4,000 to 4,500 feet. 

 The predominating rock in these mountains is clay slate, aud are more rarely crystaline schists, 

 upheaved by porphyries, which most likely played an important part in the formation of the 

 ore deposits. At the foot of the ore bearing mountains there are strata of sedimentary for- 

 mations of different periods consisting of slates, limestones and sandstones. The ore deposits 

 belong to two classes, veins and stock works. All the vein deposits bear the general charac- 

 ter of steeply inclined, short and thick veins. They generally occur on the borders of the 

 junction of the clay slates with felsite porphyries. The vein deposits of the Salairsk mountains 

 are accompanied by veins of quartose felspar porphyries which in their zone rise to the for- 

 mation of ore bearing cavities. As a rule, stock works are rare in the Altai, and are only 

 known for the copper deposits and then they are not of great extent. 



As many as eight hundred deposits of metallic ores are known in the Altai mining 

 region. Altogether however only about five hundred mines have been exploited, out of which 

 only eight silver and two copper mines are now worked. The silver ores contain a smaller or 

 larger amount of various compounds, of copper, lead, zinc and iron, which modify the external 

 appearance, properties and richness of the ores; thus as a rule, those ores which are rich in 

 lead or copper ai'e poor in silver. The copper ores have the most uniform composition. Gold 

 is found in only two of the silver mines, the Zyrianovsk and the Ridersk, and is distributed 

 in a very variable extent throughout the deposit. Generally it appears in dependence upon a 

 decrease in the amount of silver and other metals and occurs sparingly in ore bearing quartz 

 in poor ferruginous silver ores. The metalliferous ores are either ochre or pyritic ores. The 

 ochre ores occur in the upper level of the deposits aud were formerly the chief objects of 

 exploitation. As they descend to a greater depth, the ochre ores gradually change into pyritic 

 ores. All the Altai mines, at their greatest depth of 70 to 100 sagenes, pass into a zone 

 of transition of the ochre into pyritic ores, and lioice the ore is exceedingly variable in 

 its composition and richness in metal. The ochre ores are generally richer than ihe pyritic 

 and this distinction is most evident in the case of silver ores; the transition of the ochre 

 into pyiitic ores generally has an extremely unfavourable effect upon the richness of tlie ore 

 in silver ami lead: besides which ihc sineliing of the ores becomes much more difficult, l-'or 



