古土壤钙质结核δ^(18)O重建的早白垩世古温度与哈密翼龙生存环境  

RECONSTRUCTION OF EARLY CRETACEOUS PALEOTEMPERATURES FROM δ^(18)O OF PALEOSOL CARBONATE NODULES AND ITS IMPLICATIONS FOR THE HABITAT ENVIRONMENT OF HAMIPTERUS TIANSHANENSIS

作　　者：季军良 夏依丹·沙吾尔丁 李雷[1] JI Junliang;Xiayidan SHAWUERDING;LI Lei(Hubei Key Laboratory of Critical Zone Evolution,School of Geography and Information Engineering,China University of Geosciences(Wuhan),Wuhan 430074,Hubei;Research Institute of Exploration and Development,Xinjiang Oilfield Company,PetroChina,Karamay 834000,Xinjiang)

机构地区：[1]中国地质大学(武汉)地理与信息工程学院,湖北武汉430074 [2]中国石油新疆油田分公司勘探开发研究院,新疆克拉玛依834000

出　　处：《第四纪研究》2024年第5期1163-1173,共11页Quaternary Sciences

基　　金：国家自然科学基金项目(批准号:42274105)资助。

摘　　要：哈密盆地下白垩统地层含大量翼龙、翼龙蛋和胚胎化石,是研究翼龙生存繁衍细节的宝贵材料。但是,与哈密翼龙生存环境密切相关的古气候研究成果还未见发表,这制约了对哈密翼龙“伊甸园”形成机制和翼龙演替原因的认识。本研究利用哈密盆地古土壤层钙质结核氧同位素(δ^(18)O)重建了早白垩世Barremian-Aptian早期近地表大气年均温度(MAT)。结果表明Barremian期MAT的平均值为9.04℃,Aptian早期的平均值为13.79℃,这与中亚地区陆相记录重建的MAT结果一致,且变化趋势与海相记录相符。哈密盆地Aptian早期快速升温约5℃,可能是对大洋缺氧事件OAE 1a(Oceanic Anoxic Events 1a)初期海水快速增温的陆地响应。哈密翼龙动物群主要繁盛在MAT较低的Barremian期,OAE 1a事件之后衰亡,与热河生物群的演化过程相符,可能说明全球增温事件对生物演化具有一定影响。The Lower Cretaceous strata in the Hami Basin contain abundant pterosaur,egg,and embryo fossils,providing crucial evidence for studying the details of pterosaur survival and reproduction.However,there are no published studies on the paleoclimate closely related to the living environment of the Hamipterus tianshanensis,which hinders our understanding of the formation mechanism of the"Eden"habitat for the Hamipterus tianshanensis and the reasons for their evolution.This paper reconstructs the near-surface atmospheric mean annual temperature(MAT)during the Barremian and early Aptian periods using oxygen isotopes(δ^(18)O)from calcareous nodules of the Early Cretaceous paleosol in the Hami Basin.Sections PM03(42°44.5'N,92°36.1'E)and PM68(42°27.4'N,92°44.7'E)are located on the steep slopes of the terraced landforms on the north and south sides of the Hami Basin,respectively.The ca.52 m thick PM03 section is mainly composed of lacustrine light gray to yellow-gray fine to medium-grained sandstone,with more mud clasts and abundant pterosaur fossils at the bottom and intercalated with light brown-red siltstone and paleosol layers at the top.The ca.136 m thick PM68 section is mainly composed of fluvial-lacustrine light gray to yellow-gray fine to medium-grained sandstone and conglomerate,with an increase in brown-red siltstone and paleosol layers in the upper part.Under the constraints of the Hamipterus tianshanensis fossil at the bottom of the PM03 section and the youngest age of the detrital zircons,it is inferred that the age of the PM03 section is the Barremian period.Based on the horizontal strata and the altitude,we suggest that the age of the upper part of the PM68 section is the early Aptian period.In this study,calcareous nodule samples were collected from six paleosol layers on the PM03 section,and five paleosol layers on the upper ca.70 m of the PM68 section,with the diameter of the calcareous nodules being 1~3 cm.Three calcareous nodule samples were collected from each paleosol layer in the field and cut op

关 键 词：哈密翼龙 早白垩世 古土壤钙质结核 古温度 δ^(18)O 

分 类 号：P534.53[天文地球—古生物学与地层学] Q915.864[天文地球—地质学] S153[生物学—古生物学]