大比例尺地球化学方法在地质填图中的应用

THE APPLICATION OF LARGE SCALE GEOCHEMICAL MAPPING METHOD

利用大比例尺区域化探资料中成矿元素铜、砷地球化学场的变化规律所反映的信息,在大兴安岭查巴奇浅覆盖区推断19条断裂构造带.将推断出的断裂构造带结合地球物理、遥感信息、地质填图等得到的断裂构造对比研究,结果显示:推断的断裂构造带多数与地球物理、遥感信息、地质填图等得到的断裂构造一致,多数地球化学场的分界线准确地反映了地层与侵入体的接触带,明显的地球化学高、低背景场分别对应着地层与侵入体.说明应用成矿元素地球化学信息进行地质单元推测、断裂构造推断等是有效的,可在浅覆盖区推广应用.同时,成矿元素地球化学图也存在一定的局限性,从推断结果看地球化学方法只能概略地推断地质体,实际工作中应注意与地质、地球物理、遥感等方法紧密结合,对地质填图单元进一步区分,以使提取的信息可靠性更强.

Based on the regional geochemical data, which reflect the regularity and distribution of geochemical fields of metallogenic elements of copper and arsenic in the typical forest-swamp overburden area, 19 fault belts are inferred. With comparison of these faults to those obtained from geophysical data, geological mapping and remote sensing information, the result shows that most of the inferred fault zones coincide with the latter. Most boundaries of geochemical background accurately reflect the contact zone between strata and intrusive rocks. The obvious high and low geochemical backgrounds respectively correspond to the strata and intrusive rocks. It is proved that the metallogenic element geochemical mapping method is effective in fault deducing in forest-swamp overburden area. Meanwhile, this method also has certain limitations.The result from this study shows that the geochemical method can only roughly infer geologic bodies. It should be closely integrated with geological, geophysical and remote sensing methods to further differentiate the geological mapping units so as to make the extracted information more reliable.