秦岭造山带中段重磁异常与成矿带的关系

Gravity and Magnetic Anomalies and Their Relation to the Metallogenic Belt in the Central Segment of the Qinling Orogenic Belt

成矿带的展布受地质构造的控制,而地质构造在重磁异常上有明显反映。为了研究秦岭造山带中段重磁异常与成矿带的关系,该文系统整理、处理了秦岭造山带中段已获得的重磁力测量资料,分析研究了重磁异常的展布特征、推断了研究区的断裂构造,讨论了结晶基底的起伏特征,并结合区域地质资料及矿床分布资料讨论了重磁场特征及其与地质构造、成矿带的关系。结果表明,秦岭造山带中段成矿带均分布在重、磁异常梯度带上或几组不同方向异常的交汇部位,尤其在局部重力高异常范围内及其边部梯度带上矿体富集。这一结果为研究秦岭造山带的地质演化、地质构造(尤其是深部构造)、断裂分布及下一步的成矿有利区预测提供重要的参考信息。

Distribution of metallogenic belt is controlled by geological structures that can be delineated by gravity and magneticanomalies. In order to study the relationship between gravity, magnetic anomalies and mineralization belt in the central segment of theQinling orogenic belt , we collected and processed the gravity and magnetic survey data of the Qinling orogenic belt. We also analyzedand interpreted the distribution characteristics of gravity and magnetic anomalies and inferred fault structures in the study area. Inaddition, we discussed the undulation characteristics of crystalline basement and the connection among gravity and magnetic anomalycharacteristics, geological structures and metallogenic belt, together with regional geology and deposit distribution. This study shows thatmost of the deposits are located within zones of high gravity and magnetic anomaly gradient or intersections of several groups ofanomalies in different orientations, especially in local high gravity anomaly range and along edges of a gradient belt. The results of thisresearch are useful for studying geological evolution of the Qinling orogenic belt, geological structures (especially in deep structures),fracturedistribution.Thefindingswillalsoprovideanimportantreferenceforpredictingfavorableareasofmineralization .