Interspinifex Ni Sulfide Ore from the Coronet Shoot, Kambalda: Characterization Using Microbeam X-Ray Fluorescence Mapping and 3-D X-Ray Computed Tomography
Interspinifex Ni Sulfide Ore from the Coronet Shoot, Kambalda: Characterization Using Microbeam X-Ray Fluorescence Mapping and 3-D X-Ray Computed Tomography
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DOI：
10.2113/econgeo.111.6.1509
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发表时间：
2016-09
期刊：
影响因子：
5.8
通讯作者：
S. Barnes;S. Beresford;M. Vaillant
中科院分区：
文献类型：
--
作者：
S. Barnes;S. Beresford;M. Vaillant
在硫化物液体池覆盖热侵蚀的科马提岩流的地方，开发了刺网矿石，使得硫化物占据了刺网橄榄石板块之间的空间。微束X射线荧光成像和三维X射线计算机断层扫描已被用来研究微结构和化学分带内刺的矿石从冠拍摄，坎巴尔达。在interspinifex空间的硫化物组合物相匹配的组成上覆硫化物池。铝硅酸盐，被解释为取代硅酸盐熔体，在硅酸盐-硫化物界面处形成膜，局部发展圆顶状羽流。薄膜和羽毛的特点是细骨架铬铁矿，减少了丰富的约一分米向下到interspinifex区。这些关系是这种矿石类型的原始岩浆起源的有力证据，其驱动力是致密、无粘性的硫化物液体渗透和熔化下伏岩石的强烈趋势。这种渗透-熔融界面可能是块状硫化物矿石底部的共同特征，根据下盘岩石的岩性和断裂特征而采取不同的形式。
Interspinifex ores are developed where pools of sulfide liquid overlie thermally eroded komatiite flows, such that sulfide occupies the space between spinifex olivine plates. Microbeam X-ray fluorescence mapping and 3-D X-ray computed tomography have been used to investigate microstructures and chemical zonation within interspinifex ores from Coronet shoot, Kambalda. Sulfide compositions in the interspinifex space match the composition of the overlying sulfide pool. Aluminous silicate, interpreted as displaced silicate melt, forms a film at the silicate-sulfide interface, locally developing dome-like plumes. The film and plumes are characterized by fine skeletal chromite that diminishes in abundance over about a decimeter downward into the interspinifex zone. These relationships are strong evidence for a primary magmatic origin for this ore type, driven by the strong tendency of dense, inviscid sulfide liquid to infiltrate and melt underlying rocks. Such infiltration-melting interfaces may be a common feature at the base of massive sulfide ores, taking different forms depending on the lithological and fracturing characteristics of the footwall rocks.