CAJ | 학술논문

安徽省沙溪铜矿是长江中下游成矿带中最为典型的中生代斑岩型铜（金）矿床，为进一步扩大矿床规模，探索新的找矿靶区，需要开展成矿背景研究，以了解控矿因素和成矿规律，为找矿预测提供基础信息。沙溪铜矿主要赋存在石英闪长斑岩中，了解该岩体的三维空间分布是实现找矿突破的关键环节。本文以重磁三维反演为基础，在沙溪矿区尝试了岩性识别，成功的刻画了含矿石英闪长玢岩、黑云母二长岩、石英闪长斑岩和闪长岩等4类主要岩体的三维形态，并推测了隐伏火山机构的存在。结合大地电磁资料分析，认为沙溪杂岩体形成与西侧的深大断裂关系更密切，与庐枞盆地形成无直接关系，同时也说明沙溪斑岩铜矿与庐枞玢岩铁矿并非同一成矿体系。沙溪铜矿中铜矿体本身不能产生强的重力和磁力异常，但重磁资料可以提供岩体分布信息，地表的弱磁低重力组合、三维重磁反演中的高密度体边上的低磁性体是寻找沙溪铜金矿的有利地段，从而实现间接找矿。综合音频大地电磁探测和重磁三维反演结果分析，认为沙溪主矿带凤台山东侧的沙湖山和夏家墩及凤台山西侧深部是寻找该类型斑岩型铜金矿的有利地段。
안휘성사계동광시장강중하유성광대중최위전형적중생대반암형동（금）광상，위진일보확대광상규모，탐색신적조광파구，수요개전성광배경연구，이료해공광인소화성광규률，위조광예측제공기출신식。사계동광주요부존재석영섬장반암중，료해해암체적삼유공간분포시실현조광돌파적관건배절。본문이중자삼유반연위기출，재사계광구상시료암성식별，성공적각화료함광석영섬장분암、흑운모이장암、석영섬장반암화섬장암등4류주요암체적삼유형태，병추측료은복화산궤구적존재。결합대지전자자료분석，인위사계잡암체형성여서측적심대단렬관계경밀절，여려종분지형성무직접관계，동시야설명사계반암동광여려종분암철광병비동일성광체계。사계동광중동광체본신불능산생강적중력화자력이상，단중자자료가이제공암체분포신식，지표적약자저중력조합、삼유중자반연중적고밀도체변상적저자성체시심조사계동금광적유리지단，종이실현간접조광。종합음빈대지전자탐측화중자삼유반연결과분석，인위사계주광대봉태산동측적사호산화하가돈급봉태산서측심부시심조해류형반암형동금광적유리지단。
Shaxiporphyry copper-gold deposit located in Lujiang county where named as Luzong (Lujiang-Zongyang)ore concentrate district,Anhui province,east China.This deposit is the most typical Mesozoic porphyry copper-gold deposit in the middle and lower reaches of Yangtze River.In order to expand scale of the deposit,it ’s necessary to research metallogenic background to understand ore-control factor and metallogenic characteristics,and then provide basical information for mineral exploration.Quartz diorite porphyry is the main ore bearing pluton in Shaxi deposit,so mapping the three-dimensional space distribution of the pluton is a key step for prospecting.Based on the 3D inversion of gravity and magnetic, we tried the lithology recognition and successfully portrays the three-dimensional morphology of four main types of pluton include ore bearing quartz diorite porphyry,biotite monzonite,quartz diorite porphyry and diorite,and we also speculated a canceled mechanism of the volcano.Analysis with magnetotelluric data,we think the formation of Shaxi intrusion complex have more closely relation with deep fault on its west side,maybe have no direct relation with the formation of Luzong volconic basin.It also proved that Shaxi porphyry copper-gold deposit and Luzong porphyrite iron deposit is not the same metallogenic system.Although copper ore can’t generate stronger gravity and magnetic anomaly,but gravity and magnetic data can provide intrusion information to realize prospecting indirectly.According gravity and magnetic 3D inversion and Audio Magnetotelluric results,we find that ore bearing quartz diorite porphyry can character as low magnetic, low density and high resistivity,so where low magnetic and gravity anomalies in surface,low magnetic body near high density body in 3D inversion model and high resistivity in Audio Magnetoteluric survey are mostly area for mineral exploration.Integrate geophysics exploration and geological interpretation,we believe that the deep part one the west of Shaxi main ore zone,Shahu mountain and Xijiadun which one the east of Fengtai mountain are favorable targets for porphyry copper gold deposit.