胶东典型含矿构造岩相带的地质—地球物理信息预测方法与找矿实践

摘要

The positioning prognosis of concealed ore deposits by the combination of geology and geophysics is the world-wide issue in ore exploration field.The relevant theories and technology have long been the hot points of research.Tectonics is the decisive factor for ore formation.The prerequisite of a successful prognosis is the exact identification of ore-controlling structures.The favorable ore-forming positions are actually the ore-bearing tectonic lithofacies zones.Based on their geological signatures and physical property parameters,the prospecting-directed classification draft of deposit geophysics is proposed.By getting rid of economic indexes of delineating ore bodies,larger ore-bearing tectonic lithofacies zones are chosen to be the predicting targets.The targeting objects are enlarged and easier to be identified by geophysical methods.Consequently,the successful rate of ore predictions is greatly improved.As examples,three typical fracture-controlling metallic ore deposits (Jiaojia,Pengjiakuang,Qibaoshan) in eastern Shandong gold concentration region are selected to specifically demonstrate the predicting procedures.Firstly,through detailed analysis of metallogenic regularity and field survey,the ore-bearing tectonic lithofacies zones are identified and metallogenic model is established.Subsequently,physical parameters of geological bodies in the zone are measured by effective geophysical methods to study their spatial distribution and affecting factors.Consequently,the geological-geophysical exploration models are established and favorable prospecting targets are selected.Finally,test engineering is designed and good prospecting result is achieved.%地质与地球物理相结合的隐伏矿床定位预测是矿产勘查领域的世界性难题,相关的理论与技术是研究热点.构造是成矿的决定性因素,准确识别控矿构造是预测成功的首要条件,有利的成矿构造部位就是含矿的构造岩相带.依据构造岩相标志及其物性参数特点,提出了面向找矿预测目标的矿床地球物理类型划分方案.摆脱经济指标对矿体范围的限制,将更大规模的含矿构造岩相带作为预测目标,提高了物探方法的识别精度,预测成功率随之显著提高.选择胶东金矿集区内受断裂构造控制的焦家、蓬家夼、七宝山3个典型金多金属矿田,具体介绍了该预测方法的操作程序.首先,在详细的地质观察测量基础上,分析成矿规律,识别含矿构造岩相带,建立成矿地质模型.然后,测量含矿地质体的物性参数,研究其分布规律和影响因素,进而选择有效的地球物理方法和观测系统,完成数据采集、处理和解释,建立地质-地球物理勘查模型,优选找矿靶区靶位.最后,实施工程验证,取得良好的找矿效果.