【摘要】 胶东土堆—沙旺金矿床位于胶莱盆地东北缘，是牟平—乳山成矿带西侧新探明的金矿床。为探明矿床成矿物质来源并明确矿化时间，选择主成矿阶段载金黄铁矿和闪锌矿样品开展S、Pb同位素测试，对成矿期二长花岗岩开展Pb同位素测试和LA-ICP-MS锆石U-Pb测年研究。黄铁矿和闪锌矿的δ³⁴S值变化范围分别为-1.6‰～2.2‰和-1.5‰～0.7‰，成矿物质主要来源于岩浆。硫化物Pb同位素²⁰⁶Pb/²⁰⁴Pb、²⁰⁷Pb/²⁰⁴Pb与²⁰⁸Pb/²⁰⁴Pb测试结果分别为18.147～18.347、15.496～15.589和38.247～38.423。二长花岗岩Pb同位素²⁰⁶Pb/²⁰⁴Pb、²⁰⁷Pb/²⁰⁴Pb和²⁰⁸Pb/²⁰⁴Pb测试结果分别为18.244～18.350、15.486～15.557和38.259～38.363，硫化物和二长花岗岩具有相似的Pb同位素特征，表明土堆—沙旺金矿床的成矿物质主要来源于二长花岗岩，且壳—幔混源特征显著。与金矿化密切相关的二长花岗岩LA-ICP-MS同位素测年结果为（116±2）Ma（N=17,MSWD=2.4），该年龄与区域上大规模金矿化事件的时间基本一致，表明金矿化时代为早白垩世晚期。结合区域构造演化历史，认为在早白垩世晚期，太平洋板块向欧亚大陆板块俯冲，致使华北克拉通发生岩石圈拆沉减薄和大规模地幔上涌，引起壳—幔物质交换，形成二长花岗质岩浆，分异出的含矿热液沿NE向构造断裂向上运移至浅部形成土堆—沙旺金矿床。更多还原

【Abstract】 The Tudui-Shawang gold deposit is situated on the northeastern margin of the Jiao-Lai Basin,and on the western side of the Muping-Rushan gold mineralization belt.To ascertain the source of ore-forming materials for the Tudui-Shawang gold deposit,we conducted sulfur and lead isotope analyses on sulfides,such as goldbearing pyrite and sphalerite,during the main mineralization stage,as well as on the ore-associated monzogranite.Furthermore,LA-ICP-MS zircon U-Pb dating studies and lead isotope analyses were performed on the monzogranite closely linked with the gold mineralization to determine the age of mineralization.The δ³⁴S values of five pyrite samples and three sphalerite samples range from -1.6‰ to 2.2‰ and -1.5‰ to 0.7‰，respectively,suggesting that the ore-forming materials originated from magmatic sources.The lead isotope ratios for the sulfides are ²⁰⁶Pb/²⁰⁴Pb:18.147～18.347,²⁰⁷Pb/²⁰⁴Pb:15.496～15.589,and ²⁰⁸Pb/²⁰⁴Pb:38.247～38.423.The lead isotope ratios for the monzogranite are ²⁰⁶Pb/²⁰⁴Pb:18.244～18.350,²⁰⁷Pb/²⁰⁴Pb:15.486～15.557,and²⁰⁸Pb/²⁰⁴Pb:38.259～38.363.The ore-forming materials in the Tudui-Shawang gold deposit exhibit a mixed crustmantle origin,as indicated by similar lead isotope results,in sulfide and monzogranite.LA-ICP-MS zircon U-Pb dating of monzogranite associated with gold mineralization yields a weighted average age of （116±2）Ma（N=17,MSWD=2.4）,aligning with regional large-scale gold mineralization events,suggesting a late Early Cretaceous age for the mineralization.During this period,the Pacific plate subducted beneath the Eurasian,plate,transforming the North China Craton from extrusion to extension tectonics.This tectonic shift,characterized by mantle uplift and lithospheric thinning,triggered significant magmatic activity,facilitating crust-mantle material exchange and the formation of ore-bearing monzogranitic magma.Consequently,ore-bearing hydrothermal fluids were transported upward along the NE-tectonic faults to form the Tudui-Shawang gold deposit at shallow depth.更多还原