Anatomy of a eustatic event during the Turonian (Late Cretaceous) hot greenhouse climate

作     者：Bilal U. HAQ Brian T. HUBER 

作者机构：Department of PaleobiologyMRC-121Smithsonian InstitutionWashington D C 20013USA SorbonneISTEP Pierre&Marie Curie UniversityParis 75005France 

出 版 物：《Science China Earth Sciences》 (中国科学（地球科学英文版）)

年 卷 期：2017年第60卷第1期

页      面：20-29页

核心收录：

学科分类：070903[理学-古生物学与地层学(含：古人类学)] 0709[理学-地质学] 07[理学] 

基　　金：a contribution to IGCP Project 609 "Climate-environmental deteriorations during greenhouse phases:Causes and consequences of short-term Cretaceous sea-level changes " 

主　　题：Eustatic event Turonian Hot greenhouse climate 

摘      要：Sequence stratigraphic studies consider relative change in sea level(as regulated by eustasy,local tectonics and sediment supply)as the main builder of the stratigraphic *** has generally been considered as a consequence of the growth and decay of continental ice sheets that would explain large,rapid changes in sea level,even during periods of relative global climatic ***,such a mechanism has become increasingly difficult to envision during times of extreme global warmth such as the Turonian,when the equator-to-pole temperature gradient was very low and the presence of polar ice seems *** paper investigates the timing and extent of sea level falls during the late Cenomanian through Turonian,especially the largest of those events,sequence boundary KTu4,which occurred during the middle to late Turonian peak of the Cretaceous hot greenhouse *** conclude that the amplitude of the widespread third-order sea level fall in the middle Turonian that is centered at^91.8 Ma varies at different locations depending on the influence of dynamic topography on local tectonics and regional climatic *** volume variations seem unlikely as a mechanism for controlling sea level at this ***,this causal factor cannot be ruled out completely since Antarctic highlands(if they existed in the Late Cretaceous)could sequester enough water as ice to cause eustatic *** ascertain this requires detailed tomographic imaging of Antarctica,followed by geodynamic modeling,to determine whether high plateaus could have existed to accumulate ephemeral ice *** mechanisms for sea level change,such as transference between ground water(a small amplitude shorter time scale effect)and the ocean and entrainment and release of water from the mantle to the oceanic reservoir(a potentially large amplitude and longer time scale process),are intriguing and need to be explored further to prove their efficacy at third-order time scales.