Geological characteristics and mineralization stage division of algal limestone facies stratified breccia in the Huayuan lead-zinc deposit

There are huge reserves of MVT type lead-zinc deposits in west Hunan, and hence this area has good metallogenic prospect.Stratified algal limestone facies is the main prospect direction and the mineralized breccia is the key symbol for ore prospecting, but the method for distinguishing the characteristics of bedded breccia needs to be further studied.This paper mainly focuses on the study of lead-zinc deposit with the purpose of discussing the breccia mineralization process and analyzing the geological characteristics of breccia in different metallogenic stages.According to observation and analysis of breccia and cement, the breccia is divided into three different mineralization stages: ①Breccia formed prior to mineralization: this kind of breccia does not contain minerals, and there is no mineralization phenomenon in both breccia and cement.Stratoid breccia and striate breccia are the main types of this kind of breccia; ②Breccia of metallogenic stage: this kind of breccia contains mineralization in both breccia and cement.Stockwork ore-bearing breccia, porphyry veinlike ore-bearing breccia, veinlike ore-bearing breccia and disseminated ore-bearing breccia are the main types of this kind of breccia.③ Breccia of post- metallogenic: this kind of breccia contains a small amount of mineralization and most of mineralization phenomena exist in the breccia instead of in the cement.Irregular network veins breccia is the main type of this kind of breccia.The identification of the mineralization stage of breccia has important reference value for using tectonic and rock facies to study geological prospecting and regularity of mineralization.