浙江省长兴县煤山剖面二叠-三叠系过渡地层中的黑碳记录及其地质意义  

Black carbon record across the Permian—Triassic boundary section at Meishan,Changhsing County,Zhejiang Province and its significance

作　　者：沈文杰 林杨挺[1] 孙永革[2] 徐琳[3] 张华[4] 

机构地区：[1]中国科学院地质与地球物理研究所地球深部重点实验室,北京100029 [2]中国科学院广州地球化学研究所,有机地球化学国家重点实验室,广州510640 [3]中国科学院国家天文台,北京100012 [4]中国科学院南京地质古生物研究所,南京210008

出　　处：《岩石学报》2008年第10期2407-2414,共8页Acta Petrologica Sinica

基　　金：中国科学院知识创新重要方向项目(编号:kzcx2-yw-110);青年科学基金项目(编号:40702017)资助

摘　　要：首次报道了浙江煤山二叠—三叠系界线地层中黑碳的含量及其碳同位素的变化特征。黑碳含量在26层存在一个明显的峰值,含量高达0.51%。黑碳与总有机碳比值从25层底部开始持续升高,在26层达到最高,稳定在0.40以上。黑碳的碳同位素在24层和25层之间有一个陡然的降低,降低幅度达2‰,在25和26层中则存在一个幅度达3‰的缓慢降低,总降低幅度达5‰。黑碳是动植物和化石燃料燃烧的天然记录,浙江煤山二叠—三叠系界线附近黑碳特征反映了二叠纪末期陆地生态系统发生了突然的衰退,发生了强烈的天然大火。根据事件层大火燃烧的长期性或频繁的特征,以及黑碳同位素大幅度陡然降低和缓慢降低,认为燃烧源除了陆地植被外,还有其他富含轻碳的化石燃料,即大火的燃烧源除了植被外,还可能有煤和甲烷水合物等。浙江煤山剖面的黑碳记录,反映了二叠—三叠纪之交地球陆地环境的剧烈变化,有助于理解和揭示生物大灭绝的过程和原因。Black carbon content and carbon isotope were first reported in the Permian-Triassic boundary strata at Meishan, Changhsing County, Zhejiang Province, China. A main black carbon peak occurs in bed 26 with the value of 0. 51% and a minor in bed 24 of 0. 20%. The ratio of bleak carbon to totall organic carbon steady rises from the bottom of bed 25 and reaches its peak in bed 26 with the value above 0.40. Carbon isotope of black carbon decreases 2‰ sharply from bed 24 （MSC24f0） to bed 25 （MSC25a） and then 3‰ steadily from bed 25 to bed 26. Black carbon record in the Permian--Triassic boundary section at Meishan, a natural record of biomass and fossil material burning, reveals abrupt ecosystem collapse on land and intensive wildfires occurring at the end of the Permian. According to the long lasting or frequent wildifres and large carbon isotope shift of about 5‰ at event bed （bed 25 and bed 26）, coal and methane hydrate are possible materials for burning besides biomass on land. The black carbon record in Meishan Permian--Triassic boundary, indicating abrupt changes of the Earth＇ s surface environment, contributes to understanding the process and cause of mass extinction.

关 键 词：黑碳 碳同位素 大火 煤山剖面 二叠-三叠系界线 

分 类 号：P597.2[天文地球—地球化学]