岩石矿物学杂志2025，Vol.44Issue(6)：1359-1380,22.DOI:10.20086/j.cnki.yskw.2025.5018
新疆巴什苏洪双峰式侵入岩年代学、地球化学及其地质意义
Geochronology,geochemistry and geological significance of the Bashisuhong bimodal intrusive rocks in Xinjiang
摘要
Abstract
The Bashisuhong rare earth deposit is located at the northern margin of the Tarim Basin and the southern Tianshan region,at the junction between the Tarim Craton and the Central Asian Orogenic Belt.There has been on-going debate regarding its formation age and tectonic attributes.To address these issues.this study focuses on the bimodal intrusive rocks discovered in the region and attempts to provide evidence to resolve the aforementioned problems.Through petrographic,zircon U-Pb geochronology,in situ Hf isotope analysis and geochemical studies of the rocks,the results show that the zircon U-Pb ages of the diabase and alkaline granite are 278.50±0.87 Ma and 275.89±0.94 Ma,respectively,indicating their formation in the Middle Permian.In terms of geochemical charac-teristics,both rocks have similar εHf(t)values(diabase average:4.17,alkaline granite average:3.42).The al-kaline granite has high SiO2,K2O,Na2O,and low MgO,CaO,with relatively high total rare earth element con-tent,significant light/heavy rare earth element ractionation,and a distinct negative Eu anomaly,along with enrich-ment in high-field-strength-elements.The diabase has lower SiO2,K2O,higher MgO,CaO,relatively lower total rare earth element content,significant light/heavy rare earth element fractionation,a weak positive Eu anomaly,and elevated Ba content.In terms of rock genesis,the diabase originates from the asthenospheric mantle,undergo-ing low-degree partial melting;the alkaline granite magma originates from partial melting of lower-pressure,high-temperature crustal gabbro,displaying characteristics of A1-type granites.Combined with regional geological back-ground analysis,it is concluded that the Bashisuhong alkaline intrusive complex formed in a non-orogenic intra-con-tinental rift environment during the Middle Permian,driven by mantle plume activity,rather than in a post-collision orogenic extension tectonic background resulting from plate stress release.This provides new data for the study of the Late Paleozoic tectonic setting in the northern margin of Tarim.关键词
巴什苏洪/双峰式侵入岩/锆石U-Pb定年/地球化学/地幔柱Key words
Bashisuhong/bimodal intrusive rocks/zircon U-Pb dating/geochemistry/mantle plume分类
天文与地球科学引用本文复制引用
林浩,周玉,陈世忠,杨乐,李君阳,张东明..新疆巴什苏洪双峰式侵入岩年代学、地球化学及其地质意义[J].岩石矿物学杂志,2025,44(6):1359-1380,22.基金项目
新疆维吾尔自治区天池英才(青年博士)引进计划 （青年博士）
新疆维吾尔自治区2022年度第二批重大科技专项(2022A03009-3) （2022A03009-3）
新疆维吾尔自治区自然科学基金项目(2022D01A148) The Tianchi Talent(Young Doctor)Recruitment Program of Xinjiang Uygur Autonomous Region （2022D01A148）
2022 Annual Second Batch Major Science and Technology Project of the Xinjiang Uygur Autonomous Region(2022A03009-3) （2022A03009-3）
Natural Science Foundation Project of Xinjiang Uygur Autonomous Region(2022D01A148) （2022D01A148）
