沉积与特提斯地质2025，Vol.45Issue(2)：394-407,14.DOI:10.19826/j.cnki.1009-3850.2024.12004
云南保山地块S型花岗岩的年代学特征:对原特提斯洋演化的约束
Geochronological characteristics of S-type granites of the Baoshan block in western Yunnan:Constraints on Proto-Tethys Ocean evolution
摘要
Abstract
The Baoshan block records important information of early Paleozoic magmatism,providing a natural window to reveal the tectonic evolutionary features of the Proto-Tethys Ocean in western Yunnan.In this study,detailed petrological,petrographic,geochemical,and zircon U-Pb geochronological data of the Caojian two-mica granite within the Baoshan block are presented.Results show that two representative granite samples have zircon U-Pb ages of(449±3)Ma and(451±2)Ma,respectively,indicating late Ordovician magmatic activity occurred in the Caojian area.The two-mica granite has a high aluminum saturation index(A/CNK＞1.2)and belongs to peraluminous granite.The samples display enrichment in large ionic lithophilic elements(LILEs)and depleted in high-field-strength elements(HFSEs),with right-sloping chondrite-normalized REE patterns and obvious negative Eu anomalies.These data indicate that the Caojian two-mica granites belong to S-type granite,and are derived from the partial melting of metamorphic mudstone under high temperature conditions,and fractional crystallization occurred during the process of magmatic evolution.They are formed in a transitional background from syn-collision to post-collision,which implies that the Proto-Tethys Ocean in western Yunnan tended to disappear in the late Ordovician.关键词
原特提斯洋/早古生代/年代学和地球化学/花岗岩/保山地块Key words
Proto-Tethys Ocean/early Paleozoic/geochronology and geochemistry/granite/Baoshan block分类
地质学引用本文复制引用
焦显杨,周云,刘希军,刘奕志,陈丛敏,覃悦,蔡永丰..云南保山地块S型花岗岩的年代学特征:对原特提斯洋演化的约束[J].沉积与特提斯地质,2025,45(2):394-407,14.基金项目
国家自然科学基金(42473063) （42473063）
广西重点研发计划(桂科AB22035045) （桂科AB22035045）
