A Study on the Geological Characteristics and Genetic Types of Dashipo Andalusite Deposit in Yingjiang County, Yunnan Province

Abstract

The Dashipo andalusite deposit in Yingjiang County, Yunnan Province is taken as an example in this article to discuss the geological characteristics of andalusite ore occurrence and to analyze the genesis of the deposit. The ore body is mainly found in the middle strata of the Upper segment of the Gaoligongshan Group in the Middle Proterozoic (Pt2gl2), with the ore-bearing layers consisting of Andalusite mica schist, Andalusite mica quartz schist, and Andalusite mica quartz schist. The main features of the deposit include its super-large scale, the medium to stable distribution of the ore layer, and the uniform grade changes. Most of the red feldspar in the deposit is composed of self-shaped to semi-self-shaped long columnar metamorphic crystals that are distributed along the schistosity of the ore layer. The ore material has a simple composition with relatively low content of harmful components, making it rare in China. Based on the location of the deposit, characteristics of the ore body, structural features of the ore, mineral associations, and chemical composition of the ore, it is preliminarily believed that the deposit belongs to the regional metamorphic type, which holds great significance for searching for similar types of deposits.