上海张堰铜矿外围地球物理场特征与找矿前景分析

Geophysical Field Characters and Prospecting Analysis in Out-ring Region of Zhandyan Copper Deposit in Shanghai

上海张堰铜矿外围地球物理场特征与找矿前景分析杨达忠华东有色地勘局８１４队，镇江，２１２００４ＧｅｏｐｈｙｓｉｃａｌＦｉｅｌｄＣｈａｒａｃｔｅｒｓａｎｄＰｒｏｓｐｅｃｔｉｎｇＡｎａｌｙｓｉｓｉｎＯｕｔ－ｒｉｎｇＲｅｇｉｏｎｏｆＺｈａｎｄｙａｎＣｏｐｐｅ...

Zhangyan Copper Deposit in Shanghai, a middle-sized copper deposit, is being carried out with an additional exploration. Its out-ring region is a favourable for the seeking of hidden copper deposit. The deposit is considered as a stratabound skarn-type deposit formed by a superimposed and reformed activities. According to the view point, the gravity and magnetic anomalies existed in Shenjiabang section, a out-ring region of the deposit are explained and deduced. Through an analysis in the physical properties of rocks and minerals as well as geological data, the gravity anomaly is mainly caused by Presinian Jinshan Group and bedrock uplift; the magnetic anomaly is mainly caused by a superimposed activity of the magnetic bed(ore-bearing bed) of metamorphic rock series in Presinian Jinshan Group and anomaly produced by Jurassic magnetic volcanic rocks.Accouding to the treatment on the data of gravity and magnetic anomalies and the interactive nomnal fitting calculation of gravity and magnetic anomalies in the region ,the result shows that the theoretical curve is basically the same as measured curve. The stratum and faulted structures are classified and the ore-bearing beds are deduced based on the geophysical model. It is deduced that the integrated section of Jinshan Group and granite as well as Jurassic volcanic rock series reflected by gravity and magnetic anomalies is a favourable section for the seeks of stratabound copper deposit formed by a superimposed and reformation arter Upper Proterozoic volcanic eruption and metagenesis. The superimposed character of gravity and magnetic anomalies shows the existence of ore-bearing bed.