The Protolith Restoration And Gold Mineralization Of Rixen Deposit In Ulu Sokor, Peninsula Malaysia

Ulu Sokor gold field, which is located in the Central Gold Belt of peninsula Malaysia, is one of the few gold fields with breakthrough in the exploration. Rixen gold deposit is located in the northern part of Ulu Sokor. In this paper, with Rixen as the study area, the author has studied the tectonic environment formation and the protolith restoration of metamorphic rocks, then analyzed its relationship with gold mineralization. With regional metallogeny and geochemistry as the guides, the data collected through field geological survey, petrography, petrochemistry and trace element geochemical.The studies of petrography and geochemical on Rixen shown that it is a series of epimetamorphic rock consist of tuffaceous phyllite, crystal tuff and phyllite. The protolith is of basalt、andesite and rhyolite set of mainly intermediate-basic pyroclastic rocks from the study of protolith restoration. It can be concluded that the protolith is a set of intermediate and intermediate-acid pyroclastic rocks by comparing the petrographical characteristics.According to comparative analysis of wall rock geochemical characteristics of Rixen and New Discovery-Ketubong gold deposits, Rixen and New Discovery-Ketubong gold deposits basically share the same geochemistry characteristics. Both are identified as calc-alkaline and aluminum-oversaturated series, enriched with LILE including Ba, Rb, Th, K, and depleted HFSE covering P, Ti, Nb, Ta, shown that it’s a typical "TNT" anomaly. While the high content and uniform distribution of LREE shown the typical characteristics of island arc volcanic rocks. After combined with the tectonic discrimination diagrams, it can be concluded that the epimetamorphic rock formed in the volcanic arc of accretionary continental margin.Combined with the regional metallogeny background, since northwards subduction of the Palaeo-Tethys ocean beneath Indochina, the Peninsula Malaysia experienced multiple basic and ultrabasic crust-source magmatism and a series of N-S oriented linear structures. The collision between Indosinian Block and Sibumasu Block during the Permian-Triassic period caused the melting of upper oceanic crust, forming intermediate-compositions magma, which is a series of intermediate volcanic rocks of marine sedimentation. The strata are not only the source of gold mineralization, but also control migration, accumulation and precipitation of the ore bearing fluid, then control morphology of the ore body. It has obscure direct relationship with magmatism.