三叠纪—侏罗纪之交准噶尔盆地南缘野火记录及全球对比  

Wildfire Records Across the Triassic⁃Jurassic Boundary in the Southern Margin of the Junggar Basin,and Global Correlations

作　　者：张新智 吕沛宗 方琳浩 杨涵 邓胜徽[3] 卢远征[3] 房亚男 张小宇 黄汝婷 梁佳宝 师生宝[1,2] ZHANG XinZhi;LÜ PeiZong;FANG LinHao;YANG Han;DENG ShengHui;LU YuanZheng;FANG YaNan;ZHANG XiaoYu;HUANG RuTing;LIANG JiaBao;SHI ShengBao(College of Geosciences,China University of Petroleum(Beijing),Beijing 102249,China;State Key Laboratory of Petroleum Resource and Prospecting,China University of Petroleum(Beijing),Beijing 102249,China;Research Institute of Petroleum Exploration and Development,PetroChina,Beijing 100083,China;Nanjing Institute of Geology and Paleontology,Chinese Academy of Sciences,Nanjing 210008,China)

机构地区：[1]中国石油大学(北京)地球科学学院,北京102249 [2]中国石油大学(北京)油气资源与探测国家重点实验室,北京102249 [3]中国石油天然气股份有限公司勘探开发研究院,北京100083 [4]中国科学院南京地质古生物研究所,南京210008

出　　处：《沉积学报》2022年第2期473-483,共11页Acta Sedimentologica Sinica

基　　金：国家自然科学基金(41502024);中国石油大学(北京)青年拔尖人才项目(2462014YJRC027)。

摘　　要：三叠纪—侏罗纪之交(距今约201 Ma)是地球历史上的关键时期,中大西洋火成岩省(Central Atlantic magmatic province,CAMP)快速地侵位和喷发,给全球的表生系统带来巨大的环境压力,其中之一是被广泛报道的同期野火事件。但此前的报道多集中在CAMP直接作用范围区内,对其是否具有全球性,以及是否是受CAMP的因果影响还存有争论。在新疆准噶尔盆地南缘的陆相三叠系—侏罗系界线的郝家沟剖面,进行系统地采样和测试分析发现:该剖面三叠系—侏罗系界线附近地层存在燃烧成因的多环芳烃(PAHs)含量的异常高值,并且与地层中指示CAMP侵位或喷发的Hg/TOC高峰值具有很好的对应关系,为全球首个对CAMP活动区外的高纬度陆相地层中三叠纪—侏罗纪之交野火记录的报道。通过与全球其他三叠系—侏罗系典型剖面的综合对比,推论CAMP活动与野火事件频率急剧地升高具有因果关系,但并非直接火源点燃的关系;推断野火频率激增可能是全球性事件,并预测在全球更广的范围内相应地层中也可观测到类似现象。The Triassic-Jurassic transition(~201 Ma)was a critical period in the Earth’s history.The rapid emplace⁃ment and eruption of the Central Atlantic Magmatic Province(CAMP)put huge environmental pressure on the global surface ecosystem.One example was the synchronous wildfire events reported widely.However,previous reports have commonly focused on the area directly influenced by the CAMP.It is debatable whether the wildfire events were a global or a regional phenomenon.This study systematically collected samples across the Triassic⁃Jurassic boundary(TJB)in the Haojiagou section at the southern margin of the Junggar Basin,Xinjiang.Abnormally high values of combustive-derived polycyclic aromatic hydrocarbons(PAHs)were found around the TJB.The anomalies correspond well with the Hg/TOC peaks,indicating the CAMP emplacement or eruptions.This is the first report on wildfire re⁃cords across the Triassic⁃Jurassic transition in high-latitude terrestrial strata outside the CAMP region.It is concluded from integrated global TJB correlations that the sharply rising wildfire frequency was triggered by the CAMP effect,but CAMP volcanism itself was not the direct igniting source.Increased wildfire frequency is inferred as a global event beyond the regions of CAMP activity,and similar wildfire records across the TJB could be observed on a global scale.

关 键 词：三叠纪—侏罗纪 准噶尔盆地 汞浓度异常 多环芳烃 野火 

分 类 号：P532[天文地球—古生物学与地层学]