ANALYSIS ON THE FORMATION OF PERLITE DEPOSITS IN NORTHEAST CHINA

The perlite deposits in Northeast China are distributed mainly in Mesozoic continental basins. The ore-bearing horizon mostly lies in the early Mesozoic acid-intermediate volcanic rocks, with orebodies as quasi-strata trending NNE. The deposits belong to marginal island arc type, formed with the sudden drop of temperature and pressure when large amount of volatile component released from the acid magma. The ore-searching might be directed to the Mesozoic acid volcanic rocks, especially the newly-formed volcanic basins with NNE extension. The bulb-shaped rhyolite, vesicular rhyolite and tuff, which are closely associated with perlite, all serve as good prospecting indicators.