地质学报2026，Vol.100Issue(6)：2044-2057,14.DOI:10.19762/j.cnki.dizhixuebao.2025487
甘肃北山扫子山辉长闪长岩成因及地质意义
The petrogenesis and geological significance of the Saozishan gabbro diorite in the Beishan area,Gansu Province
摘要
Abstract
To understand mantle-derived magmatism and tectonic evolution in the Hongshishan area of the Central Asian Orogenic Belt,this study presents LA-ICP-MS zircon U-Pb ages,whole-rock major and trace element geochemistry,and Sr-Nd isotopic data from the Saozishan gabbro-diorites in Beishan,Gansu Province.The zircon U-Pb age of 327.3±2.4 Ma represents the crystallization age.The samples exhibit low SiO2(45.72％～55.40％)and moderate MgO contents(4.18％～5.43％),with significant enrichment in large-ion lithophile elements(LILEs;e.g.,Rb and K),depletion in high field strength elements(HFSEs;e.g.,Nb and Ta),and right-dipping REE patterns featuring light REE enrichment and heavy REE depletion,with weak negative Eu anomalies(Eu/Eu*=0.77～0.99).Initial 87Sr/86Sr ratios(0.704109～0.704911)and εNd(t)values(-2.0 to+2.1)indicate that the gabbro-diorites were derived from a spinel lherzolite mantle source with negligible crustal contamination.These features suggest that the Saozishan gabbro-diorites formed in a continental arc setting induced by the southward subduction of the Hongshishan Ocean,implying that subduction of the Paleo-Asian Ocean continued into the Early Carboniferous.关键词
辉长闪长岩/北山/中亚造山带/地球化学/早石炭世Key words
gabbro diorite/Beishan/Central Asian Orogenic Belt/geochemistry/Early Carboniferous引用本文复制引用
智超,陈镇海,陈生民,金鹏,杨涅,徐士龙,程哲,李奇维..甘肃北山扫子山辉长闪长岩成因及地质意义[J].地质学报,2026,100(6):2044-2057,14.基金项目
本文为新疆兵团科技计划重点领域科技攻关项目(编号2025AB061)、甘肃有色地勘局张掖矿产勘查院科技攻关项目(编号HTSP202407030004)和甘肃省重大专项项目"甘肃祁连山-北山重要矿集区金铜钨多金属矿成矿与增储示范"(编号26ZDFF001)联合资助的成果. （编号2025AB061）
