老挝长山成矿带与花岗岩有关的铜金铁矿床的成矿模式

Ore-forming model for Cu-Au-Fe ore deposits associated with granites in the Truongson ore-forming belt of Laos

老挝作为"特提斯成矿域"的重要组成部分,具有丰富的矿产资源,尤其是铜、金、铁、铝、钾盐等优势矿产与中国具有很强的互补性。初步论述了老挝的成矿地质背景和近年来发现的与花岗岩类有关的斑岩型铜-金矿床、矽卡岩型铁矿床的矿化地质特征、矿石矿物特征、矿化与岩体的空间关系,在此基础上初步建立了其成矿模式。基于同位素定年数据和Hf-Rb-Ta元素判别图,推测这些花岗岩及与其相关的矿床形成于晚石炭世华南地块向印支地块俯冲产生的火山岛弧环境。

As an important part of the Tethyan metallogenic domain,Laos contains abundant mineral resources,especially rich Cu,Au,Fe,Al,and potash salt.Laos could exchange mineral advantages for economic advantages with China.The authors studied in detail the ore-forming geological background of the Truongson ore-forming belt in Laos,mineralization features and ore minerals of newly discovered porphyry Cu-Au deposits and skarn Fe ore deposits as well as their spatial relationships to the granite intrusions.On such a basis,an ore-forming model was tentatively established for the porphyry Cu-Au deposits,thus laying a foundation for building their ore-finding patterns and searching for the same ore deposits in this ore-forming belt.Based on both zircon U-Pb dating and the discrimination diagrams of Hf-Rb-Ta trace elements,it is inferred that these granites and related ore deposits might have been formed in an island arc setting developed by the subduction of the South China block beneath the Indochina block during Late Carboniferous.