| 1 | Metallogenesis related to Mesozoic Granitoids in the Nanling Range, South China and Their Geodynamic Settings显示文摘Affected by the compressive stress from the South-Central (Indo-China) Peninsula, the Indosinianorogenesis, characterized by collision, thrust and uplifting, took place inside the South China Plate during 250?230 Ma.The ages of the Indosinian granitoids in the Nanling Range and vicinity areas are mostly 240?205 Ma, indicating that theywere emplaced in both late collision and post-collision geodynamic environments. No important granite-relatedmetallogenesis occurred in this duration. A post-orogenic setting started at the beginning of the Yanshanian Period, whichcontrolled large-scale granitic magmatism and related metallogenesis. This paper makes the first attempt to divide theYanshanian Period into three sub-periods, i.e. the early, middle and late Yanshanian Periods, based mainly on the featuresof magmatism, especially granitoids and related metallogenesis and their geodynamic environments. The magmaticassociation of the Early Yanshanian (about 185?170 Ma) comprises four categories of magmatism, i.e. basalt, bimodalvolcanics, A-type granite and intraplate high-K calc-alkaline (HKCA) magmatism, which indicates an extension-thinningof lithosphere and upwelling of mantle material to a relative small and local extent. Pb-Zn, Cu and Au mineralizationsassociated with HKCA magmatism represents the first high tide of Mesozoic metallogenesis in the Nanling Range area.During the middle Yanshanian, the lithosphere was subjected to more extensive and intensive extending and thinning, andhence mantle upwelling and basaltic magma underplating caused a great amount of crust remelting granitoids. This periodcan be further divided into two stages. The first stage (170?150 Ma) is represented by large-scale emplacement of crustremelting granites with local tungsten mineralization at its end. The second stage (150?140 Ma) is the most important timeof large-scale mineralizations of non-ferrous and rare metals, e.g. W, Sn, Nb-Ta, Bi, Mo, Be, in the Nanling Range area.The late Yanshanian (140?65 Ma) was generally characterized by full extension and breakup of the lithosphere of SouthChina. However, owing to the influence of the Pacific Plate movement, the eastern part of South China was predominatedby subduction-related compression, which resulted in magmatism of calc-alkaline and shoshonite series and relatedmetallogeneses of Au, Ag, Pb-Zn, Cu and (Mo, Sn), followed by extension in its late stage. In the Nanling Range area, thelate Yanshanian magmatism was represented by granitic volcanic-intrusive complexes and mafic dikes, which aregenetically related to volcanic-type uranium and porphyry tin deposits, and the mobilization-mineralization of uraniumfrom pre-existing Indosinian granites. | HUA Renmin CHEN Peirong ZHANG Wenlan YAO Junming LIN Jinfu ZHANG Zhanshi GU Shengyan LIU Xiaodong QI Huawen | 2005 | Acta Geologica Sinica(English Edition)2005，79，6： | 22 |
| 2 | Geochemical Characteristics of Rare Earth Elements of Guidong Granitic Complex and Their Relationship with Uranium Mineralization显示文摘The Guidong granitic complex is constituted by Luxi pluton, Xiazhuang pluton, Maofeng pluton, Sundong pluton, Aizi pluton and Siqian pluton, which intruded in Indosinian and early Yanshanian Periods. These plutons varies from each other not only in major element content, aluminium saturation index, but also in ∑REE, δ_ Eu , and LREE/HREE, (La/Yb)_N, (La/Sm)_N and (Gd/Yb)_N ratios. Uranium mineralization is mainly hosted by strong peraluminous granites, which has undergone intense fluid-rock interaction, and their REE compositions are characterised by M-type tetrad effects and lower ∑REE, δ_ Eu value, LREE/HREE, (La/Yb)_N, (La/Sm)_N and (Gd/Yb)_N ratios. | Zhang Zhanshi Hua Renmin Liu Xiaodong Deng Ping Wu Lieqin | 2005 | Journal of Rare Earths2005，23，6： | 1 |
您所在的机构暂未开通此部分的功能，请联系管理员