安徽省濉溪县杨桥孜铜金矿重磁异常特征

FEATURES OF GRAVITATIONAL AND MAGNETIC ANOMALY IN THE YANGQIAOZI COPPER-GOLD ORE DEPOSIT, SUIXI COUNTY, ANHUI PROVINCE

杨桥孜铜金矿是皖北覆盖区以地质理论为指导通过综合物探手段发现的一处中型矽卡岩型矿床。该矿床是皖北地区迄今为止发现的规模最大金矿床,对三铺岩体成矿预测、皖北地区找矿、研究华北陆块找金方向具有重要意义,为覆盖区综合找矿方法提供了成功经验。重磁勘探在该矿床的发现过程中发挥了重要作用,重磁组合异常特征倍受关注。杨桥孜金铜矿位于重力梯级带的次级鼻状重力高异常区,重力二阶导数异常与矿体分布相吻合;地磁场以正异常为背景,局部叠加明显的强磁异常,强磁异常与铁矿体分布一致,铜金矿体对应于磁力梯级带。重高磁高、重高磁梯组合异常在矿床普查过程中发挥了作用。

The Yangqiaozi copper-gold ore deposit is a medium skarn ore deposit found in the thick overburden area of North Anhui by using integrated geophysical survey method guided by geological theory. The deposit is the biggest gold ore deposit ever found so far in the area. It is of significance to prognosis of ore formation in the Sanpu rock mass, mineral exploration in North Anhui, and research of gold prospecting direction in the North China landmass, providing a successful experience for mineral exploration in the area with heavy overburden.Gravitational and magnetic survey played a major role in the discovery and the composite anomaly features attracted high attention. The deposit lies in the secondary nose-like high gravitationally anomalous area of the gravity gradient zone, and the gravitational second derivative anomaly coincides with distribution of ore body. In the background of positive magnetic anomaly, it is locally overlapped with strong magnetic anomaly, which is in line with iron ore body. Copper-gold ore body corresponds to magnetic gradient zone. The composite anomalies of gravitational high and magnetic high and gravitational high and magnetic gradient played their part in the general survey phase of the deposit.