CAJ | 학술논문

为揭示庐枞矿集区三维结构，深化对成矿作用的认识，为深部找矿提供更多信息，作者在庐枞矿集区实施了相互交叉的五条综合地球物理探测剖面。综合分析反射地震、MT 及区域重磁数据，提出了矿集区上地壳结构、组成和构造变形的新认识。庐枞矿集区东西结构由“两坳一隆”组成，即西侧的潜山-孔城坳陷和东侧的庐枞火山岩盆地，二者之间以一隆起相隔；南北结构呈“南坳北隆”阶梯式台升，两个“台阶”断裂分别为汤家院-砖桥断裂、庐江-黄姑闸-铜陵拆离断层。庐枞火山岩盆地呈不对称“箕状”，四周由向盆地倾斜的边界断裂围限。北、东边界断裂（BF2、LHTD）为深断裂，控制火山岩盆地的发展与演化。构造上，矿集区由“三横六纵”断裂系统构成，从北到南的“三横”依次为：庐江-黄姑闸-铜陵拆离断层、汤家院-砖桥断裂和仪津-陶家巷断裂（BF3）；从西到东的“六纵”依次为：郯庐、滁河（CHF）、罗河-缺口、枞阳-黄屯、陶家湾-施家湾断裂和沿江断裂带。矿集区的形成与演化主体上受燕山陆内造山运动的影响，经历了中-晚侏罗世古太平洋板块NW向挤压和白垩纪的伸展。本文还取得了一系列新发现。确定了“沿江断裂”为逆冲断裂系，庐江-黄姑闸-铜陵断裂为向南倾斜的低缓拆离断层；新发现汤家院-砖桥断裂，该断裂将庐枞火山岩盆地和潜山-孔城坳陷分为南北两部分。庐枞火山岩东北部，发现保存相对完好的早、中侏罗世沉积盆地，盆地呈NWW-SEE走向，深达5．0km，认为它可能是印支期陆-陆碰撞后伸展阶段形成的盆地。
위게시려종광집구삼유결구，심화대성광작용적인식，위심부조광제공경다신식，작자재려종광집구실시료상호교차적오조종합지구물리탐측부면。종합분석반사지진、MT 급구역중자수거，제출료광집구상지각결구、조성화구조변형적신인식。려종광집구동서결구유“량요일륭”조성，즉서측적잠산-공성요함화동측적려종화산암분지，이자지간이일륭기상격；남북결구정“남요북륭”계제식태승，량개“태계”단렬분별위탕가원-전교단렬、려강-황고갑-동릉탁리단층。려종화산암분지정불대칭“기상”，사주유향분지경사적변계단렬위한。북、동변계단렬（BF2、LHTD）위심단렬，공제화산암분지적발전여연화。구조상，광집구유“삼횡륙종”단렬계통구성，종북도남적“삼횡”의차위：려강-황고갑-동릉탁리단층、탕가원-전교단렬화의진-도가항단렬（BF3）；종서도동적“륙종”의차위：담려、저하（CHF）、라하-결구、종양-황둔、도가만-시가만단렬화연강단렬대。광집구적형성여연화주체상수연산륙내조산운동적영향，경력료중-만주라세고태평양판괴NW향제압화백성기적신전。본문환취득료일계렬신발현。학정료“연강단렬”위역충단렬계，려강-황고갑-동릉단렬위향남경사적저완탁리단층；신발현탕가원-전교단렬，해단렬장려종화산암분지화잠산-공성요함분위남북량부분。려종화산암동북부，발현보존상대완호적조、중주라세침적분지，분지정NWW-SEE주향，심체5．0km，인위타가능시인지기륙-륙팽당후신전계단형성적분지。
In order to study the 3D structure of Lu-Zong ore-district,better understand the metallogenesis and provide in-depth information for deep mineral exploration,the author have finished five intersecting integrated geophysical profiles with total length of more than 300km.The survey methods include high resolution reflection seismic,magnetotelluric sounding(MT)and regional gravity.Some new discoveries were obtained regarding the upper crustal structure and deformation based on the integrated analysis of reflection seismic,MT,regional gravity and aeromagnetic data.In general,the Lu-Zong ore-district consist of “two depression one uplift”,e.g.,Qianshan-Kongcheng depression in the west and Lujiang-Zongyang volcanic basin in the east,a uplift exist just in between.The north south structure shows a northward step-like uplift,two step-like faults are WNW-ESE trending Tangjiayuan-Zhuanqiao fault and Lujiang-Huangguzha-Tongling fault respectively.Lu-Zong volcanic basin presents a non-symmetrical shape with four inward dipping boundary faults.The northern and eastern boundary faults (BF2 and LHTD)are deep faults,which control the development and evolution of the Lu-Zong volcanic basin.Tectonically, there are three WNW-ESE trending faults and six NE-SW trending faults cutting over the ore-district. From north to south,they are Lujiang-Huangguzha-Tongling detachement fault,Tangjiayuan-Zhuanqiao fault and Yijing-Taojiaxiang fault (BF3);from the west to the east,six faults are Tan-Lu,Chihe,Luohe-Quekou,Zongyang-Huangtun,Taojiawan-Shijiawan and Along river fault.The formation and tectonic evolution of the ore-district was mainly affected by the Yanshanian intracontinental orogenic movement, and experienced the Middle~Late Jurassic contraction deformation due to the paleo-Pacific NW-trending subduction and Cretaceous extension deformation.Some other new findings regarding the nature of the faults were first obtained,e.g.,the Along river fault is a thrust fault in nature,Lujiang-Huangguzha-Tongling fault is a SW-dipping detachement,the Tangjiayuan-Zhuangqiao fault is newly determined, which divide the Lu-Zong volcanic basin and Qianshan-Kongcheng depression into northern and southern parts.In the northeast of Lu-Zong ore-district,a NWW-SEE trending,probably the Early or Middle Jurassic basin was found from the seismic image with depth up to 5. 0km,the author consider it to be the product of post-collision extension of Indosinian movement during the middle and early Late Triassic.