【摘要】 为探测长江中下游成矿带庐江-枞阳白垩纪火山岩盆地的深部构造和地壳结构,2007年初在庐枞火山岩盆地进行了以深反射地震剖面探测为主的,新一轮重力、磁力和大地电磁剖面测量。作者在前人研究的基础上对庐枞火山岩盆地及其外围重、磁场特征进行了研究。作者首先分析长江中下游地区重、磁场的分布特征,然后以区域重、磁场特征为背景来认识庐枞地区重、磁场的分布特征。研究各类地质体的物性参数是开展地球物理解释的前提,文中收集并分析了前人对庐枞地区的岩石物性的较为系统研究成果。为了提取重、磁异常的特征,文中对重、磁异常进行了位场转换和图像处理。利用新的深反射地震剖面探测和大地电磁剖面研究成果,采用定性和定量解释方法对庐枞地区重、磁场的分布特征进行了研究并提出新的认识。庐枞火山岩盆地深部存在隐伏的磁性强的中碱性岩类是产生区域磁异常的主要原因。庐枞火山岩盆地下部火成岩所侵入的地层向盆地东南方向延伸,盆地的西北边界向东南方向倾斜。而在罗河断裂带以西没有火成岩存在。亦即庐枞火山岩盆地是一个沿北东向罗河断裂向东发育的非对称火山盆地。另外,在庐枞火山岩盆地西部边缘罗河深部存在切穿莫霍面的断裂带沿北东向延展数十千米。更多还原

【Abstract】 In order to explore the crustal structure of Lujiang-Zongyang volcanic basin in Middle-Lower Yangtze rift metallogenic belt during Cretaceous,deep reflection seismic,magnetotelluric,magnetic and gravity profiles through volcanic basin were finished in 2007.On the basis of the new data,we study the feature of gravity and magnetic anomalies of Luzong volcanic basin and its periphery.We analyzed the gravity and magnetic anomalies of in Middle-Lower Yangtze rift area firstly.We analyze the rock physical characteristics,and process the gravity and magnetic data in Luzong area by using transformation of potential field and image processing technique.Gravity and magnetic modeling is restricted in the deep reflection seismic data.We suggest that the phenomena of high regional magnetic anomaly are mainly caused by the intermediate-alkaline rocks buried in the Luzong volcano basin.The research results of the gravity and magnetic models and the feature of gravity and magnetic anomalies support the idea that the "ear-shape" Luzong basin was a dissymmetrical basin along Luohe fault with north-east strike direction and eliminated the judgment that another half basin was buried,below red layer,west side of Luohe fault.In addition,the Luohe fault,which cuts across the MOHO,trend several ten kilometers in the direction of NE.更多还原