深水源—汇系统对多尺度气候变化的过程响应与反馈机制  

Process⁃product Linkages and Feedback Mechanisms of Deepwater Source⁃to⁃sink Responses to Multi⁃scale Climate Changes

作　　者：龚承林[1,2] 齐昆 徐杰 刘喜停 王英民[2] GONG ChengLin;QI Kun;XU Jie;LIU XiTing;WANG YingMin(State Key Laboratory of Petroleum Resources and Prospecting,China University of Petroleum(Beijing),Beijing 102249,China;College of Geosciences,China University of Petroleum(Beijing),Beijing 102249,China;School of Ocean Sciences,China University of Geosciences(Beijing),Beijing 100083,China;College of Marine Geosciences,Ocean University of China,Qingdao,Shandong 266100,China)

机构地区：[1]油气资源与探测国家重点实验室,中国石油大学(北京),北京102249 [2]中国石油大学(北京)地球科学学院,北京102249 [3]中国地质大学(北京)海洋学院,北京100083 [4]中国海洋大学海洋地球科学学院,山东青岛266100

出　　处：《沉积学报》2021年第1期231-252,共22页Acta Sedimentologica Sinica

基　　金：国家自然科学基金项目(41802117,41972100)。

摘　　要：源—汇系统对多尺度气候变化的响应与反馈是当前深水沉积学研究的前缘和新动向。通过梳理外陆架—深水盆地沉积物搬运分散系统(深水源—汇系统)对从构造尺度到人类尺度气候变化的过程响应,揭示了两种(迟滞和瞬态)深水源—汇系统的过程响应与反馈机制。迟滞响应深水源—汇系统的过渡区较宽、响应尺度较大(Teq≥104年),有利形成条件为:宽陆架且无峡谷延伸到内陆架以及冰室气候;其沉积物搬运分散过程主要受到可容空间的驱动(吻合经典的Exxon层序地层学理论)。在迟滞响应深水源—汇系统中,构造—轨道尺度的冰室气候期浊流活动较强、形成的沉积体相对富砂,温室气候期浊流活动较弱、形成的沉积响应相对富泥;而亚轨道—人类尺度的气候波动常被快速海平面上升所“淹没”、不能调控深水沉积物搬运分散过程。瞬态响应源—汇系统过渡区较局限、响应尺度较小(Teq≤104年),有利形成条件有:窄陆架、温室气候、峡谷头部和河口相接或相邻、断陷湖盆以及三角洲越过陆架坡折,其沉积物搬运分散过程对物源供给更为敏感,主要受物源供给驱动(偏离经典的Exxon层序地层学理论)。在瞬态响应深水源—汇系统中,不论是构造—轨道尺度的气候变化还是亚轨道—人类尺度的气候波动,只要其能够诱发物源供给的变化(而不论可容空间是上升还是下降),都能够对深水源—汇过程响应进行调控。The responses of sourcetosink(S2S)systems to climate change is the frontier area for new research directions in deepwater sedimentology and stratigraphy.The primary purposes of this research are to review deepwater depositional responses of outer shelftodeepwater basin S2S systems(deepwater S2S systems)to tectonicand historicalscale climate changes.This revealed two main processproduct linkages(buffered and reactive)and feedback mechanisms of S2S systems to climate change.Buffered deepwater S2S systems have wide transfer zones and a long response timescale of≥104 yr.Favorable geological settings forming this type of deepwater S2S systems are:wide shelf without channels reached at inner shelf and Icehouse climates.Sediment routing processes along buffered deepwater S2S systems are driven by accommodation(i.e.,compatible with classical Exxon sequence stratigraphic models).There was vigorous turbiditycurrent activity and resulting sandy products during tectonicto orbitalscale cooling periods,and by contrast,weak turbiditycurrent activity and resulting muddy deposits during tectonicscale to orbitalscale warming periods.Suborbitalto historicalscale climatic fluctuations might be“masked”by the rising sealevel,and thus had little effect on sedimentrouting processes in deep water.Reactive deepwater S2S systems,by contrast,have narrow transfer zones and a relatively short response time of≤104 yr.Favorable geological settings forming this type of deepwater S2S system are:narrow shelf,greenhouse climates,close proximity of canyon heads to shorelines,lacustrine basins,shelfmargin deltas overreached at the shelf break.These were more sensitive to sediment supply,and thus they are supplydriven(i.e.,incompatible with classical,Exxon sequence stratigraphic models).Along reactive deepwater S2S systems,any suborbitalscale to historicalscale climatic fluctuations are able to trigger the changes in sediment supply,regardless of sealevel conditions.

关 键 词：深水沉积 气候变化 层序地层学 迟滞响应源—汇系统 瞬态响应源—汇系统 

分 类 号：P618.13[天文地球—矿床学]