Laterite Profile Geochemistry in Outlining Supergene Gold Deposits: A Case Study from Nilambur, Kerala
Laterite Profile Geochemistry in Outlining Supergene Gold Deposits: A Case Study from Nilambur, Kerala
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描绘表生金矿床轮廓的红土剖面地球化学：喀拉拉邦 Nilambur 的案例研究
DOI：
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发表时间：
1996
期刊：
影响因子：
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通讯作者：
M. Santosh
中科院分区：
文献类型：
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作者：
P. Omaña;M. Santosh
最近，从北方喀拉拉邦的尼兰布尔红土风化剖面中发现了一个非常纯的金的天然例子。红土是高度铁质和结节状，含有腐泥和粘土层。在红土的不同层位中，金以小颗粒或金块的形式存在。在许多情况下，氧化区含有高浓度的金，与氧化铁/氢氧化物基质密切相关，并观察到结晶。这种产状支持风化过程中金的溶解和再沉淀。对尼兰布尔Maruda地区风化剖面两个代表性垂直剖面不同层位的红土样品进行了主要成分分析。微量元素和微量元素，包括本研究中的金。Fe、Al、Si、Ca、Mg、Na、K、P、Ti、Mn等元素在剖面中的分布与热带风化环境中的元素活动模式有一定的对应关系。结果表明，红土化过程中形成了以酸性为主的环境，有利于金的流动。我们的研究证实，红土中自然提纯的金是通过风化前缘的酸性含氧流体实现的。
A natural example for exceedingly pure gold was recently identified from the laterite weathering profiles of Nilambur, northern Kerala. The laterites are highly ferruginous and nodular, containing saprolite and clayey horizons. Within the various horizons in the laterites, gold is found as small grains or nuggets. In many cases, the oxidised zone contains high concentrations of gold, closely associated with iron oxide/hydroxide matrix and was observed to be crystalline. This occurrence supports dissolution and reprecipitation of gold during weathering. Laterite samples from different horizons of two representative vertical sections of the weathering profiles in the Maruda area of Nilambur have been analysed for major. minor and trace elements, including gold in this study. The distribution of Fe, Al, Si, Ca, Mg, Na, K, P, Ti and Mn in these profiles can be correlated with the element mobility patterns associated with tropical weathering environment. The results indicate that a predominantly acidic environment is generated during lateritization, which is conducive to gold mobility. Our study confirms that the concentration of naturally purified gold in the laterites was achieved by acidic oxygenated fluids in the weathering front.