西秦岭铅锌矿区域地球化学成矿预测模式

以成矿系列理论为指导,将区域内的铅锌矿按地球化学特征划分为贫铁型和富铁型2个亚系列,进而用逻辑信息法建立了西秦岭铅锌矿床区域地球化学场预测模式,验证结果较为理想。模式表明,贫铁型矿床的成矿环境为相对封闭还原的构造空间;富铁型矿床完整地反映了该类型铅锌矿床沉积成矿特点显著,而断裂等构造对成矿的直接影响相对不显著。与白银铜矿区域地球化学预测模式相比较,富铁型铅锌矿床中除铁族元素指示基性—超基性岩侵入事件外,其他元素均大致相似,两大类矿床形成的初始热动力条件不同。

A REGIONAL GEOCHEMICAL PROGNOSTIC MODEL FOR LEAD-ZINC DEPOSITS IN WEST QINLING

In this paper,with the metallogenic series theory as the guide and the geochemical data as the basis,all lead-zinc ore deposits in the region were classified into two sub-series,i.e.,LF type(with low content of iron group elements) and HF type(with high content of iron group elements),and a regional geochemical prognostic model was set up by using the logical information method.The model holds that the metallogenic environment of the LF type is structural reductive space whereas that of the HF type reflects entirely characteristics of sedimentary minerallization,with no evidence of tectonic minerallization.A comparison of the prospecting model of the HF type with the prediction model of the VMS type reveals that their thermal dynamic mechanisms are different: the former is related to basic-ultrabasic rock intrusion,while the latter to acidic rock intrusion.