1.32 Ga基性岩床侵位的环境效应探究  

Environmental Effects on the Emplacement of 1.32 Ga Mafic Sills

作　　者：张朝鲲 田伟[1] 何衍鑫 朱伟鹏 李舜 ZHANG Chaokun;TIAN Wei;HE Yanxin;ZHU Weipeng;LI Shun(School of Earth and Space Sciences,Peking University,Beijing 100871;School of Information Science and Technology,Fudan University,Shanghai 200433)

机构地区：[1]北京大学地球与空间科学学院,北京100871 [2]复旦大学信息科学与工程学院,上海200433

出　　处：《北京大学学报（自然科学版）》2024年第6期1067-1078,共12页Acta Scientiarum Naturalium Universitatis Pekinensis

基　　金：国家重点研发计划(2022YFF0800301)资助。

摘　　要：为了探究中元古代时期地球深部动力与全球碳循环过程、环境变化及星球演化的关系,选取北京黄土贵剖面,对1.32 Ga燕辽地区基性岩床的侵位特征及环境效应进行研究。通过岩石学及数值模拟分析,发现1.32 Ga基性岩床以“岩浆指”的形态侵位于围岩中,对围岩产生显著的热效应,使富碳围岩中有机质的镜质体反射率显著提升,有机质由未成熟阶段演化至过成熟阶段;该期基性岩床侵位于华北以及北澳大利亚克拉通地层,热释气量可达3.61×10^(12) t当量的CO_(2),促进地壳沉积物中碳的活化,具有明显的环境效应。In order to explore the relationship between deep earth dynamics and global carbon cycling processes,environmental changes,and planetary evolution during the Mesoproterozoic era,the Huangtugui Section in Beijing was selected as a stratigraphic section for studying the characteristics and environmental effects on the emplacement of 1.32 Ga mafic sills in Yanliao area.Through petrological and numerical simulation analysis,it was found that the 1.32 Ga mafic sills intruded into the surrounding rocks with the form of“magma finger”,resulting in significant thermal effects on the surrounding rocks.The emplacement of the sills significantly increased the vitrinite reflectance of organic matter in the surrounding rocks,evolving from an immature stage to an overmature stage.The thermal degassing of the sills in North China Craton and North Australia Craton released an equivalent of 3.61×10^(12) tons of CO_(2),promoting the activation of carbon in the lithosphere and having obvious environmental effects.

关 键 词：燕辽地区 基性岩床 环境效应 中元古代 数值模拟 

分 类 号：P588.124[天文地球—岩石学] P534.3[天文地球—地质学] P59