【作者】 霍明宇；

【导师】 张庆龙；

【作者基本信息】 南京大学 ， 构造地质学， 2012， 硕士

【摘要】 安徽省池州市马头铜钼矿位于下扬子板块北缘,属于长江中下游断裂拗陷带与皖南加里东造山带的交接部位。自震旦系到第四系均很发育,仅缺失中下泥盆统、下石炭统部分地层。在印支期后本区发育北北东向褶皱及断裂构造,印支晚期、燕山期和喜山期不同方向的断裂构造复合,构成了本区网格状构造的基本格架。区内岩浆活动强烈,Cu、Mo矿体赋存在马头花岗闪长斑岩岩体和志留系中统坟头组的接触带内外,受岩体及围岩中的密集节理带发育程度控制。本文对区内的断裂构造和节理构造特征进行了较为详细深入的研究。分析了研究区铜钼矿赋存条件和容矿构造的发育特征,系统测量统计了容矿节理的产状,应用极射赤平投影等方法进行了归纳整理,绘制出矿体的水平投影图、剖面图以及成矿期的构造应力场分布图,研究取得如下认识：1、区域内发育包括西峰庙一马头断层在内的系列平移走滑断层,走向N—S至NNE—SSW方向,反映的本区构造应力场最大主应力轴方向为NNE-SSW,最小主应力轴方向为NWW-SEE,倾角近水平,中间主应力轴近直立。容矿节理构造性质为张节理、活动期次为一期、优势产状为走向NE15。,倾向NW285。,倾角87。,反映的古应力场的最大主应力轴(σ1)的方位为15。,最小主应力轴(σ3)的方位为105。,中间主应力轴(σ2)的近垂直。容矿节理与导矿断层受到同一构造期同一构造场控制。2、研究区受到印支运动和燕山运动的重大影响,成矿期发生在燕山晚期。印支期,古构造应力场以N-S向为主,该期构造带呈E-W向至NEE-SWW向大致平行展布。燕山运动期,古构造应力场从初期的NW-SE方向,逐渐扭转成NNE向强烈左旋剪切构造应力场,发育一系列NNE到NE褶皱和逆掩断层。西峰庙-马头断层(F1)被花岗闪长斑岩侵入后,受NNE向的区域应力场的作用,断裂端部应力集中,导致张性节理的规模发育。3、马头铜钼矿矿液的导矿通道是F1深断裂,容矿构造是F1断裂端部的张性节理。矿化体的品位和形状与张性节理的发育程度和发育范围成正相关,并与应力集中与否吻合较好,可以作为找矿依据。更多还原

【Abstract】 Matou copper-molybdenum, Chizhou city, Anhui province, north margin of lower Yangtze plate, which located in the joint part of the middle and lower Yangtze fracture and sag zone and the Caledonian orogenic belt of south Anhui. From Sinian to Quaternary, the strata are well developed but the Middle-Lower Devonian and parts of the Lower Carboniferous. NNE trending folds and fractures formed after Indosinian epoch, together with other structures formed during Late Indosinian epoch, Yanshanian epoch, and Himalayan epoch established the grid tectonic framework of the study area.The magmatism is intense in the area. Cu and Mo Occurrence rock mass developed in internal or external contact zone of granodiorite porphyry and Fentou formation of Middle Siluric which controlled by fissure concentrated zones of the rock mass and surrounding rock.This paper studied the fracture and joint structure and analyzed the development characters of ore-bearing structures and the Cu-Mo Occurrence Conditions. A statistics of attitudes of the host joints was made systematically by stereographic projection and so on. We draw the horizontal projection map, cross-section map and distribution graph of tectonic stress field during the metallogenic period. The main results achieved and understanding are as follows:1The N-S to NNE-SSW trending Xifengmiao-Matou sinistral strike-slip faults manifest the trending of the maximum principal stress axis(σ1)is NNE and the trending of the minimum principal stress axis (σ3) is NWW, the dip angle is nearly horizontal. The middle principal stress axis (σ2) is nearly vertical. F1as the route ways of the Matou copper-molybdenum mine initial tension joint developed in the end of the F1as the ore-bearing structures, The dominant attitudes are285°∠87°, which manifest the azimuth of the maximum principal stress axis (σ1) is15°and the azimuth of the minimum principal stress axis (σ3) is105°, the intermediate principal stress axis (σ2) is nearly vertical. Ore-bearing joints and mineral transfer structures were controlled by the same tectonic stress field.2Indosinian movement and Yanshan movement significant impact the structures of the study area, and the metallogenic happened in late Yanshan period. In Indosinian period, the mainly structure stress field is N-S compression and the trace of the structures are more or less parallel. In Yanshan period, the orientation of the compression structure stress field changed from NW-SE to NNE gradually developing a series of from NNE to NE trending faults. The Xifengmiao-Matou fault invaded by the granodiorite-porphyry produced edge stress concentration, which caused the tension joints.3F1deep fracture is the route ways of the ore solution, and the tension joints formed at the end of F1is the ore-bearing structures. The quality and shape of the mineralized bodies is positively correlated with the degree and scope of the extend joint, and that can help us prospecting.更多还原