成都理工大学学报（自然科学版）2026，Vol.53Issue(2)：403-421,19.DOI:10.12474/cdlgzrkx.2024080702
青海昆仑河晚志留世—早泥盆世S型花岗岩成因与原特提斯洋构造演化
Genesis of Late Silurian to Early Devonian S-type granites in the Kunlun River area,Qinghai Province,and the tectonic evolution of the Proto-Tethys Ocean
摘要
Abstract
The Erdaogou,Wulugouxi,and Jiazutashigouxi granites,located in the Kunlun River area of the middle part of the east Kunlun orogenic belt(EKOB),are composed of monzogranite.However,their origin and emplacement time frames remainunknown,posing a challenge to understanding the region's tectonic evolution.Results from LA-ICP-MS zircon U-Pb dating revealed crystallization ages of 423.6 Ma,427.9 Ma,and 413.8 Ma for the Erdaogou,Wulugouxi,and Jiazutashigouxi granites,respectively.These intrusions are characterized by minor muscovite,the absence of hornblende,high silica content(68.92%to 73.69%),an aluminum-rich composition(13.86%to 15.72%),and elevated total alkali content(5.50%to 7.70%).The aluminum saturation index(A/CNK)varies from 1.06 to 1.37,with corundum molecules(1.04%to 4.66%)identified in the CIPW standard mineral calculations,while the absence of clinopyroxene suggests a classification as strongly peraluminous S-type granites.High CaO/Na2O ratios along with low K2O/Na2O and Rb/Sr ratios indicate a connection to H2O-fluxed melting of metasandstones during their formation.The Zircon Ti thermometry data indicate zircon crystallization temperatures within the three granites ranging from 723 ℃ to 834 ℃,733 ℃ to 858 ℃,and 586 ℃ to 870℃,respectively.Oxygen fugacity values of zircons suggest a relatively low oxygen fugacity level during magma formation.Considering the Paleozoic magmatic rock record and our investigation of these metamorphic rocks,including high-pressure to ultra-high-pressure eclogite in the EKOB,this study proposes that the Late Silurian to Early Devonian S-type granites in the Kunlun River area originated in an extensional environment following closure of the Proto-Tethys Ocean.关键词
U-Pb年代学/S型花岗岩/昆仑河地区/东昆仑/青海Key words
U-Pb geochronology/S-type granite/Kunlun River area/east Kunlun/Qinghai分类
天文与地球科学引用本文复制引用
冯李强,沈睿文,彭艳雯,顾雪祥,章永梅,杜治利,王大伟..青海昆仑河晚志留世—早泥盆世S型花岗岩成因与原特提斯洋构造演化[J].成都理工大学学报（自然科学版）,2026,53(2):403-421,19.基金项目
新疆维吾尔自治区重点研发计划项目(2023B03016) （2023B03016）
中国地质调查局地质调查专项(DD20230374). （DD20230374）
