辽宁盘岭矿集区花岗岩锆石SHRIMP U-Pb年龄、Hf同位素组成及地质意义

发布时间：2018-12-20 12:25

【摘要】：辽宁盘岭矿集区产出在辽吉裂谷中段的草河口—草河城—黑峪一带,是一处典型的古元古代沉积盆地和多金属矿集区。矿区内发育有早白垩世的北大砬子岩体和古元古代高丽墩台岩体,与本区的矿化作用密切相关。北大砬子岩体锆石SHRIMP U-Pb年龄加权平均值为(123.9±2.2)Ma,高丽墩台岩体锆石SHRIMP U-Pb年龄加权平均值为(1 872±13)Ma。北大砬子岩体εHf(0)为负值,εHf(t)为负值(-16.86~-10.95),说明北大砬子岩体形成时壳源物质成分占主导地位,单阶段Hf模式年龄(TDM)平均为1 339 Ma,两阶段Hf模式年龄(TDMC)平均为2 043 Ma;高丽墩台岩体εHf(0)为负值,εHf(t)为正值(0.29~4.64),说明高丽墩台岩体形成时壳源物质成分占主导地位,并有地幔物质混染,单阶段Hf模式年龄(TDM)平均为2 171 Ma,两阶段Hf模式年龄(TDMC)平均为2 355 Ma。结合岩石地球化学特征得出:北大砬子岩体具有高钾钙碱性岩浆岩特征,为较高分异的过铝质I型花岗岩,是底侵岩浆提供热动力使下地壳物质部分熔融的产物,属于晚中生代大陆边缘岩浆弧环境,其与进入早白垩世古太平洋板块俯冲作用密切相关,岩浆活动直接影响盘岭矿集区内一期铜、铅、锌、钼等矿化作用;高丽墩台岩体具有低钾(拉斑)岩浆岩特征,为较高分异的过铝质I型花岗岩,是热的玄武质熔体加热下地壳使之熔融的产物,且可能有地幔物质贡献,岩体侵入诱发的一系列断裂(包括层间断裂)控制着矿集区内矿脉及岩脉的空间分布。
[Abstract]:The Panling ore accumulation area in Liaoning Province is a typical Paleoproterozoic sedimentary basin and polymetallic ore accumulation area in the middle section of Liaoji Rift. The early Cretaceous and Paleoproterozoic Gaoliantai rock bodies are developed in the mining area, which are closely related to the mineralization in this area. The weighted average of zircon SHRIMP U-Pb age is (123.9 卤2.2) Ma, and the weighted average of zircon SHRIMP U-Pb age is (1 872 卤13) Ma.. 蔚 Hf (0) and 蔚 Hf (t) (-16.86 -10.95) were negative in the Beidalazi rock mass, indicating that the crustal material was dominant in the formation of the Beidalazi rock mass. The average (TDM) age of the single-stage Hf model was 1 339 Ma,. The average age of two-stage Hf model (TDMC) is 2 043 Ma;. 蔚 Hf (0) is negative and 蔚 Hf (t) is positive (0.29 ~ 4.64), which indicates that crust material is dominant and mantle material is mixed. The average age of a single stage Hf model, (TDM), is 2 171 Ma, the average age of a two-stage Hf model is 2 355 Ma., and the average age of a Hf model is 2 355 Ma.. In combination with the petrogeochemical characteristics, it is concluded that the Beidalazi rock body is characterized by high potassium calc-alkaline magmatic rocks, and is a highly differentiated peraluminous I-type granite, which is the product of the partial melting of the lower crust material provided by the underplating magma. It belongs to the late Mesozoic continental margin magmatic arc environment, which is closely related to the subduction of the Paleo-Pacific plate into the early Cretaceous, and magmatic activities directly affect the mineralization of copper, lead, zinc, molybdenum and so on in the first stage of the Panling ore accumulation area. The Gaoli Diantai rock body is characterized by low-potassium magmatic rock, which is a highly differentiated peraluminous I-type granite. It is the product of the melting of the crust by hot Black Tortoise melt, and it may have the contribution of mantle material. A series of faults (including interlayer faults) induced by rock intrusion control the spatial distribution of veins and veins in the ore concentration area.
【作者单位】：中国地质调查局沈阳地质调查中心;吉林大学地球科学学院;吉林大学地球探测科学与技术学院;
【基金】：中国地质调查局国土资源大调查项目(12120113058800,1212011085280,DD20160049)~~
【分类号】：P588.121

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