松科3井下白垩统登娄库组米兰科维奇旋回识别及其古气候意义  

Milankovitch cycle identification of Denglouku Formation in Songliao Basin and its paleoclimate significance

作　　者：罗力铭 余蔓琳 李琦[2] 吴舟凡 黄永建[1] LUO Liming;YU Manlin;LI Qi;WU Zhoufan;HUANG Yongjian(School of Earth Sciences and Resources,China University of Geosciences(Beijing),Beijing 100083,China;School of Ocean Sciences,China University of Geosciences(Beijing),Beijing 100083,China)

机构地区：[1]中国地质大学(北京)地球科学与资源学院,北京100083 [2]中国地质大学(北京)海洋学院,北京100083

出　　处：《沉积与特提斯地质》2025年第1期112-119,共8页Sedimentary Geology and Tethyan Geology

基　　金：国家自然科学基金(42272134,41972112)。

摘　　要：在白垩纪大陆科学钻探工程的推动下,松辽盆地成为白垩纪陆相古气候研究的热点地区之一,其中松辽盆地古气候变化与全球气候变化的一致性和差异性是目前关注的重点。本文选择松辽盆地松科3井获得的登娄库组岩心,通过X射线荧光(XRF)扫描获得化学风化指标Rb/Sr比值,应用时间序列分析方法开展旋回地层学研究。分析结果表明:(1)松科3井登娄库组XRF扫描曲线中化学风化指标Rb/Sr的变化,指示了登娄库组沉积期间气候由湿润逐渐变得干旱的过程;(2)松科3井登娄库组最优沉积速率约为14.43 cm/ka,结合地层深度域的气候旋回波长,利用比值法识别出登娄库组地层中记录了白垩纪中期岁差(20~19 ka)、斜率(45~39 ka)、短偏心率(130~100 ka)和长偏心率(450~390 ka)等气候旋回周期信号,判定登娄库组记录了米兰科维奇旋回信息;(3)应用功率能量分解方法,结果表现为,早白垩世登娄库组以偏心率和岁差信号为主,斜率信号非常弱,这与全球气候变化记录具有一致性。Under the promotion of the Cretaceous continental scientific drilling project,the Songliao Basin has become one of the hotspots for the Cretaceous terrestrial paleoclimate research.Among these studies,the consistency and differences between the paleoclimate change of the Songliao Basin and coeval global climate change are currently the focus of attention.In this paper,the cores of the Denglouku Formation obtained from the continental scientific drilling of Well Songke-3 in the Songliao Basin were selected.The chemical weathering index Rb/Sr ratio was obtained through XRF scanning,and the time series analysis method was applied to study the cyclostratigraphy.The analysis results show that:(1)The variation in the chemical weathering index Rb/Sr ratio,as shown in the XRF scanning curve,indicates the process of the climate from humid to arid during the deposition of the Denglouku Formation.(2)The optimal deposition rate of the Denglouku Formation is about 14.43 cm/ka,which can be combined with the wavelength of the depth domain to identify the Milankovitch cycles preserved in the Denglouku Formation,including precession(20-19 ka),obliquity(45-39 ka),short eccentricity(130-100 ka),and long eccentricity(450-390 ka)signals of the climate cycle.(3)With the application of power decomposition analysis(PDA),it is shown that eccentricity and precession signals are dominant,while the obliquity signal is very weak in the Early Cretaceous Denglouku Formation.This is consistent with the global climate change record.

关 键 词：松辽盆地 登娄库组 米兰科维奇旋回 古气候 

分 类 号：P532[天文地球—古生物学与地层学]