古新世—始新世极热气候下陆相沉积系统响应与油气效应研究进展  

Responses of the Terrestrial Sedimentary System to Paleocene-Eocene Thermal Maximum and Hydrocarbon Resource Effects:Progress and Prospects

作　　者：谭先锋 蒋威 王敦繁 刘建平 李雯雯 严雪齐 罗龙 王佳 瞿雪姣 高儇博 TAN Xianfeng;JIANG Wei;WANG Dunfan;LIU Jianping;LI Wenwen;YAN Xueqi;LUO Long;WANG Jia;QU Xuejiao;GAO Xuanbo(School of Petroleum Engineering,Chongqing University of Science and Technology,Chongqing 401331,China)

机构地区：[1]重庆科技大学石油与天然气工程学院,重庆401331

出　　处：《重庆科技大学学报(自然科学版)》2025年第1期44-57,共14页Journal of Chongqing University of Science and Technology(Natural Sciences Edition)

基　　金：国家自然科学基金项目“古新世—始新世极热气候时期咸化湖泊物质分异作用及早期成岩行为研究”(42072140);“咸化湖盆烃源岩有机酸盐形成机制与成烃意义”(42403050);“东营凹陷早始新世干旱气候下湖相异重流沉积响应机制及油气地质意义”(42202170);“始新世—渐新世气候转型期海洋风尘铁肥效应及其碳汇机制研究”(42404087);重庆市杰出青年科学基金项目“极热气候环境下湖泊沉积-成岩系统及油气效应”(CSTB2022NSCQ-JQX0031);重庆市教委科技重大项目“极热气候高CO_(2)浓度下湖泊水介质状态及油气富集”(KJZD-M202101502)。

摘　　要：古新世—始新世极热事件(PETM)是距今最近的一次全球快速变暖事件,为类比分析当前全球快速变暖提供了很好的地质实例。然而,PETM时期陆相沉积记录研究案例较少,制约了人们关于陆相沉积系统对极热气候响应机制的深入认识。根据最新研究成果,对PETM时期陆相沉积系统响应及油气效应进行系统总结和分析,得到以下几点认识:1)PETM时期极端降雨和大陆风化增强,导致频现洪水、重力流以及高沉积速率;2)沉积环境中高盐还原条件转变为低盐氧化条件,水体富营养化,蓝藻勃发;3)在早期成岩阶段,胶结物类型变化频繁,明显受气候和水介质条件变化的控制;4)植被由低纬度向高纬度扩张,陆地土壤和陆地植被大量吸收大气中的CO_(2),与此同时高纬度冻土层融化释放大量轻碳;5)PETM时期地层的TOC含量主要受保存条件和稀释作用的控制,但仍可能具有高页岩油勘探潜力,这归因于PETM事件前后时期沉积地层的贡献。关于极热气候下陆相沉积系统响应机制的研究仍有不足甚至空白,还需深入研究极热气候事件对陆地环境演化的潜在影响,以利于预防未来陆地环境变化带来的危害和勘探极端气候时期的油气资源。The Paleocene-Eocene thermal maximum(PETM)is a latest rapid global warming event in the geological history and provides an excellent geological analogue for understanding the current global warming.However,the rare terrestrial sedimentary records during the PETM period hinder our understanding how terrestrial sedimentary systems responde to extreme warming.Based on the newest studies,responses of the terrestrial sedimentary system to PETM and hydrocarbon resource effects are systematically summarized and analyzed,and the following five viewpoints are obtained:1)Extreme rainfall and enhanced continental weathering during the PETM led to frequent floods,gravity flows,and high sedimentation rates.2)In the sedimentary environment,high-saline and reducing conditions shifted from low-salinity and oxidizing conditions with eutrophication of water column and the proliferation of cyanobacteria.3)Cement types at the early diagenetic stage varied frequently,which was controlled by climatic and hydrochemical conditions.4)Low-latitude vegetations expanded toward the high latitudes,along with terrestrial soils and vegetation absorbing large amounts of atmospheric CO_(2).Meanwhile,large amounts of light carbon were released due to the melting of high-latitude permafrost.5)The TOC content within PETM strata was mainly controlled by preservation and dilution conditions,whereas it may still have high potential for shale oil exploration due to contributions of sedimentary pre-and post-PETM strata.Nonetheless,there are still many deficiencies on understanding the responses of terrestrial sedimentary systems under extreme warming climates.Deep understanding to the impacts of extreme climate events on terrestrial environmental evolution is beneficial to prevent threats from future terrestrial environmental changes and contribute to explorations of hydrocarbon resources during extreme climates.

关 键 词：极热气候 陆相沉积系统 碳循环 油气效应 古新世—始新世 

分 类 号：P618[天文地球—矿床学]