试论临朐铁寨地区矽卡岩型铜金多金属矿床地球化学模型

Geochemical model of skarn type gold-copper polymetallic deposit in Tiezhai area of Linqu

临朐铁寨地区位于山东省潍坊市境内,地处郯庐断裂带西侧的沂山凸起北缘,围绕铁寨杂岩体,区内已发现评价了贡山—马鞍山、杨桃、寺头等多个金、银、铜(铁)矽卡岩型矿床,但矿床规模较小,分布分散。基于1∶5万水系沉积物测量成果,采用R型聚类分析和因子分析等统计手段分析研究元素组合规律,并应用元素含量-面积多重分形模型研究地球化学异常并确定了异常下限,运用异常衬值法圈定了Au、Ag、Cu等重要成矿元素的单元素异常及其指示元素的组合异常,最终结合区内NW向控矿构造、中生代燕山晚期成矿岩体以及Au、Ag、Cu等重要成矿元素富集特征,建立了地球化学异常结构模型。

Linqu Tiezhai area is located in Weifang City,Shandong Province,on the northern edge of Yishan Uplift at the west side of the Tanlu fault zone.Surrounding the Tiezhai complex,there are gold,silver,copper(iron)skarn deposits,such as Gongshan-Ma'anshan deposit,Yangtao deposit and Sitou deposit.But the deposits are scattered and the scale is small.This study is based on the geological result of 1∶50000 stream sedimentary survey.The statistical methods of R-type cluster analysis and factor analysis are used to analyze and study the regularity of element combination.The element content-area multifractal model is applied to study the geochemical anomaly and to determine the lower anomaly limit.The anomaly lining value method is used to delineate the single-element anomalies of Au,Ag,Cu and the combination anomalies of the indicator elements.The geochemical anomaly structure model is established on the basis of the NW ore-controlling structure in the area,the late Mesozoic Yanshan ore-forming intrusive body,and the enrichment characteristics of important ore-forming elements of Au,Ag and Cu.