Geology, geochemistry and metallogenesis of the Selinsing gold deposit, central Malaysia
Geology, geochemistry and metallogenesis of the Selinsing gold deposit, central Malaysia
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DOI：
10.1016/j.gr.2013.08.023
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发表时间：
2014-07
影响因子：
6.1
通讯作者：
C. Makoundi;K. Zaw;R. Large;S. Meffre;Chunkit Lai;Teh Guan Hoe
中科院分区：
文献类型：
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作者：
C. Makoundi;K. Zaw;R. Large;S. Meffre;Chunkit Lai;Teh Guan Hoe
马来西亚拥有许多主要的沉积物承载的造山金矿床，这些矿床平行于本东-劳布缝合带，但位于本东-劳布缝合带以东，该缝合带在马来西亚中部大致呈南北走向。Selinsing金存款是马来西亚中部的主要经济矿床之一，并由（Meta）沉积单元托管。该存款是在三叠纪期间由于Sibumasu地体与素可泰弧的碰撞而受到后期变形和变质作用的影响。寄主岩石的激光烧蚀ICP-MS锆石U-Pb定年表明，石炭纪（约。最大沉积年龄为331-300 Ma。矿石矿物有黄铁矿、毒砂、方铅矿、闪锌矿、黄铜矿、磁黄铁矿和金。详细的结构和地球化学研究揭示了五种不同的黄铁矿类型，亚圆形的framboidal黄铁矿（黄铁矿1），圆形的重结晶黄铁矿（黄铁矿2），他形的包裹体丰富的黄铁矿（黄铁矿3），他形的半自形清洁黄铁矿（黄铁矿4）和粗自形清洁黄铁矿（黄铁矿5）。激光烧蚀ICP-MS微量元素分析表明，相对于其他类型的黄铁矿富集V，As，Mo，Ni，Se，Te，Ag和Zn。黄铁矿硫同位素组成（1.2-9.2‰）表明硫可能是岩浆和当地沉积物的混合物。黄铁矿Pb同位素结果（Pb 206/Pb 204：18.94-19.10; Pb 207/Pb 204：15.72-15.73）表明铅的高U源岩。流体包裹体富含CO2（95-100 mol%），均一温度为194 - 348 °C，盐度为1.23 - 9.98 wt.% NaCl当量表明成矿过程中有变质流体的参与。根据这些结果，我们提出了Selinsing金存款形成的两阶段模式。第一阶段为Au、V、As、Mo、Se、Te、Ni、Ag、Zn等元素在黄铁矿中的早期富集;第二阶段为多期成岩后变形变质作用，有利于流体通道的发育和Au向晚期黄铁矿的再活化。从区域上看，Selinsing金存款矿床与东南亚大陆许多其他沉积物托管的造山型金矿床（如Sepon金存款（老挝）、Langu金存款（泰国）、Modi Taung和Meyon金矿床（缅甸）以及Dalloc Son金存款（越南中部））具有地质相似性（在寄主岩石、矿石矿物学和地球化学方面）。我们认为，我们的两阶段模型可能有重要的意义，矿产勘探，为今后的研究在东南亚的沉积物/造山型金矿床。
Malaysia is endowed with a number of major sediment-hosted, orogenic gold deposits that lie parallel to but east of the Bentong-Raub Suture Zone, which runs approximately N–S in central Malaysia. The Selinsing gold deposit is one of the major economic deposits in central Malaysia and is hosted by (meta)-sedimentary units. The deposit is affected by later deformation and metamorphism during the Triassic due to the collision of the Sibumasu Terrane with the Sukhothai Arc. Laser ablation ICP-MS U–Pb zircon dating of the host rocks indicates a Carboniferous (ca. 331–300 Ma) maximum depositional age. Ore minerals include pyrite, arsenopyrite, galena, sphalerite, chalcopyrite, pyrrhotite and gold. Detailed textural and geochemical studies revealed five distinctive pyrite types, sub-rounded framboidal pyrite (Pyrite 1), rounded recrystallized pyrite (Pyrite 2), anhedral inclusion-rich pyrite (Pyrite 3), anhedral to subhedral clean pyrite (Pyrite 4) and coarse euhedral clean pyrite (Pyrite 5). Laser ablation ICP-MS trace element analysis of the framboidal pyrite indicates enrichment in V, As, Mo, Ni, Se, Te, Ag, and Zn relative to the other pyrite types. Pyrite sulfur isotope composition (1.2–9.2‰) suggests a likely mixture of magmatic and local sedimentary source for the sulfur. Pyrite Pb isotope results (Pb206/Pb204: 18.94–19.10; Pb207/Pb204: 15.72–15.73) suggest a high-U source rock for the lead. Fluid inclusions are CO2-rich (95–100 mol%) and yielded homogenization temperatures from 194 to 348 °C and salinities between 1.23 and 9.98 wt.% NaCl equiv. suggesting involvement of metamorphic fluids during ore formation. Based on these results, we suggest a two-stage model for the formation of the gold deposit at Selinsing. Stage 1 consists of early enrichment of the elements Au, V, As, Mo, Se, Te, Ni, Ag, and Zn in framboidal pyrite in the sediments, whereas Stage 2 is characterized by multiple post-diagenetic deformation and metamorphic processes, favoring the development of fluid pathways and Au remobilization into later pyrites. Regionally, the Selinsing gold deposit shares geological similarities (in term of host rocks, ore mineralogy and geochemistry) with many other sediment-hosted, orogenic gold deposits in mainland SE Asia such as the Sepon gold deposit (Laos), Langu gold deposit (Thailand), Modi Taung and Meyon gold deposits (Myanmar), and Phuoc Son gold deposit (central Vietnam). We suggest that our two-stage model may have important implications to mineral exploration for future research on sediment-hosted/orogenic gold deposits in SE Asia.