深穿透地球化学对比研究两例

DEEP-PENETRATION GEOCHEMISTRY- COMPARISON STUDIES OF TWO CONCEALED DEPOSITS

为了寻找隐伏矿床,近些年提出了深穿透地球化学的概念和发展了深穿透地球化学方法。国际勘查地球化学家协会于1997年开始组织实施了“深穿透地球化学对比计划”。这里给出了四种深穿透地球化学方法,包括金属活动态提取方法、酶提取方法、活动金属离子法和电地球化学方法,在中国和美国的两个隐伏矿进行了对比试验,结果表明,深穿透地球化学方法可以在隐伏矿上方有效地发现异常。在干旱荒漠区,由于氧化作用和蒸发作用强烈,地表形成氧化地球化学障和大量盐类的蒸发地球化学障,这些地球化学障可以将深部迁移至地表的含矿信息捕获。因此,用深穿透地球化学的铁锰氧化物膜提取和盐类蒸发障良好导电性能的电提取,可以有效地指示矿体。中国的深穿透地球化学方法在美国内华达Mike金铜矿的效果要优于加拿大的酶提取(EnzymeLeach)和澳大利亚的活动金属离子法(MMI)。

Deep-penetrating geochemistry concepts and methods have been developed for exploration of concealed ore deposits. A Deep-penetrating geochemistry research project is designed to sharpen the techniques through comparison of the methods in various concealed deposits. This paper describes the comparison results of four methods including the Selective Leaching of Mobile Metals (MOMEO), Mobile Metal Ions (MMI), Enzyme Leach and Electrogeochemistry methods. The results show that strongly anomalous values are corresponding to the concealed deposits under 200 meters of post-ore sedimentary rocks and desert sand. Selective leaching of metals occluded in Fe-Mn oxide coatings and electrogeochemical extraction of ions are both effective for indicating to concealed deposits in arid desert terrain. Chinese MOMEO method is more effective than Canadian Enzyme Leach method and Australian MMI method in the Mike gold deposit.