海相油气地质2026，Vol.31Issue(2)：164-174,11.DOI:10.3969/j.issn.1672-9854.2026.02.005
柴西北上干柴沟组咸化湖盆天文旋回识别及沉积速率分析
Identification of astronomical cycles and analysis of sedimentation rates in the salinized lake basin of the Shangganchaigou Formation in the northwestern Qaidam Basin
摘要
Abstract
The Shangganchaigou Formation(N1)in the northwestern Qaidam Basin mainly consists of fine-grained mixed rocks deposited in a saline lake basin,representing an important field for unconventional oil and gas exploration.However,current research on cyclostratigraphy and high-precision astronomical sedimentary response characteristics in this formation remains relatively weak.By comprehensively integrating core and well-logging data,cyclostratigraphic analysis is performed on two drilling wells,identifying Milankovitch cycles including long eccentricity,short eccentricity,obliquity,and precession in the Shangganchaigou Formation,and a floating astronomical time scale is established based on the 405 ka long eccentricity cycle,thereby determining the sedimentation rate and sedimentary characteristics of the Shangganchaigou Formation.It is shown that:(1)Sedimentation time of N1 is approximately 4 Ma,and the average sedimentation rate can reach 20 cm/ka,which is significantly higher than that of other continental lacustrine strata in China.(2)The lithofacies characteristics based on sedimentation rate analysis indicate that lithofacies are significantly controlled by the sedimentation rate.Laminated dolomitic limestone with high organic matter content mainly develops in high-rate segments,while massive argillaceous-silty dolomitic limestone with low organic matter content is dominant in low-rate segments.(3)The continuous orogenic tectonic activity during the Himalayan period control the high sedimentation rate of N1 at a macroscopic scale,and short-term climate alternations shape the oscillatory changes in the sedimentation rate.The identification of astronomical cycles and analysis of sedimentation rates of N1 in the the northwestern Qaidam Basin are helpful for understanding the sedimentary evolution of favorable exploration intervals in salinized lake basins and can provide new ideas for the subsequent efficient exploration and development of shale oil.关键词
天文旋回/沉积速率/岩相/上干柴沟组/柴西北Key words
astronomical cycle/sedimentation rate/lithofacies/Shangganchaigou Formation/northwestern Qaidam Basin分类
能源科技引用本文复制引用
吴颜雄,田明智,李娴静,徐帆,王波,裴梓薇,施奇,朱超,宫清顺,刘占国,夏志远..柴西北上干柴沟组咸化湖盆天文旋回识别及沉积速率分析[J].海相油气地质,2026,31(2):164-174,11.基金项目
本文受新型油气勘探开发国家科技重大专项"柴达木盆地盆山体系油气成藏机制与新领域勘探技术"课题1"柴达木盆山耦合控盆及控藏作用"(编号:2025ZD1400601)、中国石油天然气股份有限公司攻关性应用性科技专项"超深层碎屑岩大中型油气田形成条件与有利区评价"(编号:2023ZZ14YJ01)联合资助 （编号:2025ZD1400601）
