基于GIS技术的鲁西铜石金矿聚集区综合信息成矿预测模型

A Metallogenic Prediction Model Based on GIS Technique and Comprehensive Information for the Tongshi Gold Ore Field in Western Shandong Province

鲁西铜石地区是20世纪末期新发现的金矿聚集区,地质工作程度较高。为指导成矿预测和找矿勘探,运用GIS信息技术建立了铜石地区综合信息成矿预测模型:构造控矿因子为NNW、NE、NW和EW向线型构造异常的Buffer半径1.2km;岩浆岩控矿因子为岩体的外边界以1~3km为半径范围;较强的磁力梯度带,低异常对隐伏岩体、构造的识别有指示作用;相对重力低异常,反映了铜石杂岩体的分布范围,相对重力高和条带状的低缓异常则主要反映了寒武纪地层和泰山岩群山草峪组;金元素的地球化学异常指标是寻找金矿床的最直接信息,Ag、Fe、Cu、Zn、Pb、As、Te等多种元素异常以及组合异常也可作为其重要的指示标志。

The Tongshi area in western Shandong Province is a gold ore concentrating area newly discovered in end of the 20 th century with a high degree of geologic survey. In this study,a metallogenetic prediction model for the Tongshi area is established based on GIS technique and comprehensive information to provide guidance for metallogenic prediction and prospecting. In this model,the ore-controlling factor is the buffer area of the NNW-,NE-,NW-and EW-trending structures with a radius of 1. 2km. The magmatic ore-controlling factor is within 1 ~ 3km range as the outer boundary of the rock bodies. Strong magnetic gradient zones and low anomalies are indicators of concealed rock bodies and structural identification. Relatively low gravity anomalies delineate the distribution of the Tongshi pluton,while relatively high gravity and banded gentle anomalies are indicative of the Cambrian and Taishan Group Shancaoyu Formation. Gold geochemical anomaly index is the most direct information for searching for gold deposits,and combined anomalies of Ag,Fe,Cu,Zn,Pb,As and Te can be viewed as important prospecting indicators.