Trend of Santonian (Late Cretaceous) atmospheric CO_2 and global mean land surface temperature: Evidence from plant fossils  

作　　者：WAN ChuanBiao WANG DeHai ZHU ZhanPing QUAN Cheng 

机构地区：[1]Exploration and Development Research Institute, Daqing Oilfield Company Ltd., Daqing 163712, China [2]College ofGeoseiences, Jilin University, Changchun 130061, China [3]Key Laboratory for Evolution of Past Life and Environment in Northeast China, MOE, Jilin University, Changchun 130026, China

出　　处：《Science China Earth Sciences》2011年第9期1338-1345,共8页中国科学（地球科学英文版）

基　　金：supported by the National Basic Research Pro-gram of China (Grant No. 2006CB701401);the National Natural Science Foundation of China (Grant No. 41002004);China Postdoctoral Science Foundation (Grant No. 20090451258);the Fund of LPS, Nanjing Insti-tute of Geology and Palaeontology, CAS (Grant No. 103107)

摘　　要：Quantitative reconstructions of atmospheric CO2 by using terrestrial and marine records are critical for understanding the so-called ＂greenhouse＂ conditions in the Cretaceous, but data from terrestrial plants for several stages of this period remain quite limited. Using the stomatal index （SI） technique, here we estimate the Santonian （Late Cretaceous） CO2 contents based on a sequence of fossil cuticles of Ginkgo adiantoides （Ung.） Heer from three beds of the Yong＇ancun Formation in Jiayin, Heilongjiang Province, northeastern China. By the regress function, Sis of Ginkgo fossils reveal a pronounced CO2 reduction from the early to late Santonian （-661 and -565 ppm, respectively）. The relatively high CO2 levels provide additional evidence for paleoclimatic warmth in this interval. Moreover, available paleobotanical data illustrate a decline trend of CO2 contents throughout the Late Cretaceous, punctuated by several fluctuations in particular episodes with different magnitudes. The CO2 contents shifted notably in the late Cenomanian, Turonian, early Santonian, late Campanian, and probably latest Maastrichtian. Furthermore, a comprehensive study based on CO2 data shows that the global mean land surface temperature （GMLST） fluctuated several times accordingly. The change ratios of GMLST （AT） increased from -3℃ in late Cenomanian to -4.7℃ in mid Turonian, and then dramatically reduced to -2.2℃ in mid Coniacian. From the Santonian onward, it appears that the temperature gradually decreased with a few minor fluctuations.

关 键 词：SANTONIAN Late Cretaceous global mean land surface temperature stomatal index Yong＇ancun Formation Jiayin 

分 类 号：P534.53[天文地球—古生物学与地层学] X16[天文地球—地质学]