THE GEOLOGICAL CHARACTERISTICS OF STRATABOUND IRON DEPOSITS IN THE YAMANSU FORMATION IN XINJIANG

Iron resources are very rich in the Jiangluotage area, Xinjiang. Iron ores mainly occur in the Lower Carboniferous Yamansu Formation. This formation is composed of intermediate-acid to basic lavas, pyroclastic rocks, terrigenous clastic rocks and carbonate rocks. The iron horizons mainly in the altered andesite tuffs in the upper part of the Yamansu Formation occur in the bedded, stratoid or lenticular form. Iron has a close genetic relation to intermediate volcanic eruptive rocks. There are phenomena of strong hydrothermal metasomatic alteration in various ore districts, which implies that the hydrothermal superimposition and remoulding in the late stage of mineralization were of very important significance for causing iron deposits to become higher in grade and larger in scale. Therefore, such type of iron deposit should belong to sedimentary-remoulded stratabound deposits.