SUMMARY

Types of lead-zinc mineralization in Huổi Pao and Co Gi San areas and their relationship to magmatic rocks in the T Lệ Depression

Nguyễn Văn Niệm, Mai Trọng T, Nguyễn Văn Học,

Đỗ Đức Nguyn, Đon Thị Ngọc Huyền

Lead-zinc ore in Huổi Pao and Co Gi San areas are characterized by special features, which can be divided into two types of mineralization: the first type is polymetal-silver-sulphide bearing gold occurring in Huổi Pao, while the second is polymetal-sulphide-nickel-cobalt-copper-silver occurring in Co Gi San.

The above-mentioned two types of mineralization are closely related to magmatic felsic rocks. Regarding space, lead-zinc ore is always distributed in rhyolite, rhyotrachyte, trachyte of the T Lệ and Ngi Thia Complexes and is closely related to granite, granosyenite massifs of the Phu Sa Phn Complex. About their origin, there are 2 hypotheses as follows: the first hypothesis states that ore solution and magmatic solution body are co-original, but ore solution was separated in the second stage; the second ore solution was derived from granitic, granosyenitic formations of the Phu Sa Phn Complex and gabbro formation of the Nặm Chiến Complex at the first stage (Jurassic) as well as at the final stage (19 Ma) with their source originated from effusives (T Lệ Complex) and subvolcanic rocks (Ngi Thia Complex).

Based on geochemical characteristics of ore-forming minerals of the types of mineralization, this paper determines that the denudation level of lead-zinc ore body in Huổi Pao is weak and indicator elements for ore prospecting are Pb-Zn-Sb-Ag-Cd (W).

Người bin tập: TS. Đỗ Quốc Bnh