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Northern and Southern Isak Mine
Brief description of the map of the Hage and Isak mines in Fernebo parish, Wermland county.
Introduction
In 1708, the first of the so-called So mines was opened.
The Hage and Isak mines within the area covered by the map, together with the Masungslånga and Lerp mines located to the north, form a mining field situated roughly in the middle of the southern part of the Persberg peninsula, between the Odal field and the Högberg field.
Occurrence of the ore
The ores occur as more or less regular layers embedded in hälleflinta gneiss (eurite, granulite) and appear to occupy different levels within the series of strata. This is indicated both by their relative positions and by the differing nature of the rock layers accompanying the ores in the various mines.
In the Southern Isak Mine, the host rock consists of pyroxene-garnet skarn with only a small amount of talc.
In the Hage mines, the rock consists of pyroxene skarn with somewhat more talc, while the ore in the Northern Isak Mine is accompanied almost exclusively by talc-rich rocks. In general, the ores are of good quality and belong to the better types of black iron ore.
Drainage and hoisting
Power for mine drainage is obtained from a 45-foot overshot water wheel (the Risfall Wheel), which also serves the Stor and Alabama mines within the Odal field.
For hoisting the rock, a separate 19-foot overshot wheel (the Hage Wheel) has been built for this field.
The Västra Hage Mine
The Västra Hage Mine, the southeasternmost of the long-worked so-called So mines, was opened in 1807 and worked for several years until 1820, when it was closed. It was reopened again in 1880 and has since then been continuously in operation.
The ore still occurs in two bands separated by a layer of pyroxene-garnet skarn.
Towards the south, the mine has been extended by a crosscut, which was begun in 1822. The ore bands are narrow and difficult to work, but the mine has strong walls requiring little timber support, and the ore is of good quality and much sought after.
Production
During the period 1880–1886, 221,800 centners (≈ 9,428 metric tons) of ore were hoisted, with a pig-iron yield in general assays of 55–55.8 % for first-class ore and 47–49 % for second-class ore.
Persberg, February 1887
P. Öberg
Mining Engineer, Western District
Transcription: Torbjörn Nordwall
