论文英汉互译

本科毕业设计（论文）中英文对照翻译

院（系部）资源环境学院

专业名称地质工程

年级班级 2007-02

学生姓名于换涛

指导老师马光

二0一一年六月一日

Bainiuchang super-large silver-polymetallic ore deposit

related to granitic magmatism in Mengzi, Yunnan

LIU Ji-shun(刘继顺)1, ZHANG Hong-pei(张洪培)1, 2, OUYANG Yu-fei(欧阳玉

飞)1, ZHANG Cai-hua(张彩华)2

(1. School of Geoscience and Environmental Engineering, Central South University, Changsha 410083, China;

2. Mengzi Minning and Metallurgy Co. Ltd., Mengzi County, Yunnan 661100, China)

Abstract: Bainiuchang silver-polymetallic ore deposit is located in the southeast Yunnan tin-polymetallic metallogenic belt. The probable reserves and inferred resources of the deposit are of 6470 t Ag and 1.10 Mt Pb and 1.72 Mt Zn and 86 kt Sn. Orebodies of the deposit occur in clastic-carbonate rocks of Tianpeng Formation and Longha Formation of the middle Cambrian System above the Bainiuchang concealed granite of the late Yanshan period. The concealed granite has the characteristics of tin-bearing granites.

Abundance of the mineralization elements Sn, Cu, Zn, Pb, Ag and Sb is high in the granitic rocks. Sulphur isotope data of the metal sulphides indicate that most sulphur is derived from the magmas. The ores are similar in rare earth element(REE) patterns to the granitic rocks. The granitic magma activity results in ore-bearing structures. Rocks of the Middle Cambrian System above the concealed intrusion suffer from skarnization, hornfelsing, marbleization, siliconizing and carbonatization. The mineralization elements Sn, Cu, Zn, Pb, Ag and Sb successively appear from the top of the granite to surrounding rocks. These evidences indicate that the granitic magmatism is the principal mineralization factor. The opinion that the south Bainiuchang ore field and the north Awei ore block are tin and copper potential exploration areas was put forward and was verified by drilling tests.

Key words: Bainiuchang; super-large silver-polymetallic deposit; granite; granitic-porphyry; tin ore

1 Introduction

Bainiuchang silver-polymetallic ore deposit in Mengzi County is one of the super-large deposits[1]discovered in Yunnan in 1980s. It is located in the southeast Yunnan tin-polymetallic metallogenic belt.There are three granitic intrusions, named Gejiu, Bozhushan and Dulong Laijunshan granites, which are almost equidistant outcropping in the southeast of Yunnan. The granites and the surrounding strata host three super-large tin (silver) polymetallic ore deposits. The Gejiu deposit mainly hosts Sn and Pb, and Dulong deposit mainly occurs Sn and Zn ore. The submitted probable reserves and inferred resources of the Bainiuchang deposit located at 7 km northwest Bozhushan ganite give priority to Ag-Pb-Zn. There are mainly two views to interpret the genesis of the Bainiuchang deposit at present. Some geologists regard the Bainiuchang deposit as an exhalative sedimentary mineral deposit[2−4]. Others think that the deposit is formed by exhalative sedimentary superimposed by the granitic magamatism of the Yanshan period[5−6]. Few people emphasize the importance of the granite. The tin prospecting potential for the deposit has been greatly underestimated. However, after preliminary research on the Bainiuchang deposit, it is discovered that the deposit is distinctly controlled by granites, and many evidences are conflicting with the exhalative sedimentary origin[7].

In this paper, the genetic relationship between granitic rocks and the deposit was studied, and the feasibility of tin prospecting was reviewed.

2 Geologic characteristics of Bainiuchang deposit

2.1 Geological setting

Bainiushan-Bozhushan area, which is the important part of Sn polymetallic ore belt in the southeast of Yunnan, lies in the southeast folded belt, west-extended section of South China fold system[8−10]. The exposed formation consists of Paleozoic Cambrian clastic rocks with carbonate, Lower Ordovician carbonate with clastic rocks, Devonian carbonate with clastic rocks, Carbonic carbonate and Permian carbonate-clastic rocks with basic volcanic rocks. No much Mesozoic group