矿床地质2012，Vol.31Issue(2)：229-240,12.
超基性岩红土风化壳中镍的表生富集规律及矿化结构研究——以印尼苏拉威西岛Kolonodale矿区为例
Supergene enrichment and mineralization texture of nickel in laterite weathered crust from ultrabasic rocks: A case study of Kolonodale ore district in Sulawesi Island, Indonesia
摘要
Abstract
The Kolonodale ore deposit, located in Sulawesi Island of Indonesia, was chosen as the research target for the study of the Ni supergene enrichment and mineralization texture in the laterite weathering crust from ultra-basic rock. 3 161 samples collected from 201 shallow-well profiles were analyzed for Ni grade. The results show that the average Ni grade of laterite weathered crust has good relationship with topography and land form. On the gentle slope and at hill foot, the Ni value is commonly high (0.8%～1.8%), whereas in the ridge and platform of the highland, the Ni value is relatively low (0.7%~1.4%). The average Ni grade changes in order of low(0.85 % ～ 1.55 % )→high( 1.15 % ～4.75 % )→low(≤0.55 % ) with the increasing depth from laterite layer through saprolite layer to base rock layer, suggesting that the Ni grade is related to the depth and petrological type of the sample. The modes of occurrence of ore beds, with ω(Ni)≥l.5% , change greatly but have good positive correlation with laterite weathered crust in depth and thickness. Five types of mineralization textures were distinguished, namely "normal double-layer texture", "inverted double- layer texture", "high grade single-layer texture", "low grade single-layer texture" and "laminated-layer texture". A comprehensive analysis shows that the Ni supergene enrichment and mineralization in Kolonodale area are attributed to the weathering process of the outcropped ultrabasic rock body under the conditions of active plate tectonic movement and tropical rainforest climate. Various types of mineralization texture are closely related to regional factors, such as basement rock, landform, local structure, and drainage condition. The adsorption, ion exchange and secondary deposition are considered to be the main ore-forming processes. The authors hold that various controlling factors, no matter whether they are of geological origin or of geographical origin, must be considered comprehensively in the determination of the exploration direction, and the study and summarization of the mineralization texture of the ore deposit is beneficial to further mineral prospecting.关键词
地质学/红土型镍矿/品位变化/矿化结构/成矿作用/东南亚Key words
geology, laterite nickel deposit, ore grade change, mineralization texture, ore-forming process, Southeast Asia分类
天文与地球科学引用本文复制引用
付伟,牛虎杰,陈远荣,雷良奇,黄小荣,任小瑞..超基性岩红土风化壳中镍的表生富集规律及矿化结构研究——以印尼苏拉威西岛Kolonodale矿区为例[J].矿床地质,2012,31(2):229-240,12.基金项目
本文为国家自然科学青年基金(41102051)、国家自然科学基金(40972220)与广西自然科学青年基金(桂科青0991083)联合资助的成果 （41102051）
