地质科技通报2025，Vol.44Issue(5)：95-105,11.DOI:10.19509/j.cnki.dzkq.tb20240264
琼东南盆地北礁凹陷陵水组旋回地层学及古气候分析
Cyclostratigraphy and paleoclimate analysis of the Lingshui Formation in the Beijiao Sag,Qiongdongnan Basin
摘要
Abstract
[Objective]A high-resolution,continuous chronostratigraphic framework was established using the astronomical cycles,and the paleoclimatic characteristic was analyzed for the Oligocene Lingshui Formation of the Beijiao Sag.[Methods]The cyclostratigraphy characteristics and the paleoclimatic evolution were determined by time series and multiple paleontological proxies analyses,respectively,in the Well A of the Beijiao Sag.[Results]Cycles of 405 ka long eccentricity,100 ka short eccentricity,42.7 ka and 43.2 ka obliquity,and 20.5 ka precession were identified in the Lingshui Formation of the Beijiao Sag.Considering the time anchor of 23.03 at the top of Oligocene,the astronomical tuning revealed a"floating"astronomical chronology scale of 5.59 Ma.Within the high-precision absolute astronomical timeframe of the Lingshui Formation(28.62-23.03 Ma),the bottom boundary ages of Ling Ⅰ,Ling Ⅱ,and Ling Ⅲ members can be determined as 23.97 Ma,25.43 Ma,and 28.62 Ma,respectively.These ages correspond to the average sedimentation rates of 18.4 cm/ka,8.6 cm/ka,and 12.8 cm/ka,respectively.The palaeoclimatic indicators,including the foraminifera,organic carbon,organic detrital fractions,and carbon and oxygen isotopes,suggest an overall warm-cool-warm trend during the deposition of Lingshui Formation.The comparison of palaeoclimate evolution with astronomical rotation suggested that the climate evolution during this period was mainly controlled by astronomical orbital forces such as eccentricity and age difference.Astronomical cyclostratigraphic study on the Lingshui Formation of the Beijiao Sag explores the control of astronomical orbital parameters on paleoclimate and establishes a high-resolution and continuous chronostratigraphic framework.[Conclusion]This method provides a refined chronological framework for predicting high-quality reservoir intervals in oil and gas exploration,promoting the development of oil and gas exploration in the Beijiao Sag.关键词
琼东南盆地/北礁凹陷/旋回地层学/天文年代标尺/古气候Key words
Qiongdongnan Basin/Beijiao Sag/cyclostratigraphy/astronomical time scale/paleoclimate分类
天文与地球科学引用本文复制引用
张尚锋,徐敏,唐武,徐恩泽,王雅宁,朱锐..琼东南盆地北礁凹陷陵水组旋回地层学及古气候分析[J].地质科技通报,2025,44(5):95-105,11.基金项目
中海石油(中国)有限公司重大科技项目(2021-KT-YXKY-05) （中国）
国家自然科学基金项目(41472098) （41472098）
