小秦岭北矿带北麓地质特征与找矿模型

Geological Characteristics and Prospecting Model in the Northern Slope of the Northern Metallogenic Belt,Xiaoqinling Mountains

通过对比浅部钻孔和深部地球物理资料,进一步研究了小秦岭北矿带尤其是其北麓覆盖地区深部地质特征,分析成矿演化过程,研究小秦岭深部成矿理论。结合变质核杂岩成矿理论,对小秦岭北矿带的拆离断层、后期改造断层、酸性岩体分布进行控制或物探推断,统计分析基岩面及主矿脉埋深数据规律,对酸性岩体的分布进行推断并解释了高温钼矿体的形成原因,对主矿脉深部延伸情况进行了预测。结果表明小秦岭北麓矿脉延展性好但断陷至较深位置(约2000m以深),据此建立了该地区地质找矿模型。现阶段小秦岭北矿带北麓开发难度大、形势不容乐观,提出了“地下小秦岭”的战略资源定位,可为小秦岭北矿带深部地质认识提供参考。

By comparing shallow boreholes and deep geophysical data,this work further studied the deep geological characteristics of the northern metallogenic belt,Xiaoqinling Mountains,especially the northern piedmont,analyzed the process of metallogenic evolution,and discussed the deep metallogenic theory of this area. Combining metallogenic theory of metamorphic nuclear complex,control or geophysical inference was made to the detachment fault,late reformation fault and acid rock mass distribution in this metallogenic belt. By statistical analysis to the data of bedrock surface and main vein depth,this work deduced the distribution of acid rock masses and explained the reasons for the formation of high temperature molybdenum ore bodies and predicted the deep extension of the main vein. Results suggest that the ore vein in this area extends well but roots to a deep position(about 2000 m below the surface). Based on this,we established a geological prospecting model for this area. It demonstrates that the development of this metallogenic belt is difficult at present and the situation is not optimistic. We propose the strategic resource orientation of “underground Xiaoqinling” to provide a reference for understanding deep geology in this region.