古地理学报2025，Vol.27Issue(3)：625-640,16.DOI:10.7605/gdlxb.2025.01.008
陇东地区延长组73亚段细粒沉积岩相分布规律及沉积模式:基于水槽沉积模拟实验
Distribution law and sedimentary pattern of fine-grained lithofacies in the Chang 73 submember of Yanchang Formation in Longdong area:based on flume depositional simulation experiments
摘要
Abstract
To investigate the spatial distribution and depositional patterns of fine-grained lithofacies in the Chang 73 submember of the Triassic Yanchang Formation in the Longdong area of Ordos Basin,a se-ries of flume simulation experiments were conducted.The experimental design consisted of 13 rounds grouped into three depositional stages.Quantitative data on the fine-grained depositional processes were acquired using a 3D scanner,4K high-resolution video capture,and flow velocity sensors.The experi-mental results show that:(1)Four main lithofacies were identified in the experiments:tuff,fine-to very fine-grained sandstone,siltstone,and mudstone.Based on depositional environment characteristics,nine lithofacies assemblage types were recognized;(2)From the sediment source to the deep lacustrine area,a progressive fining trend in lithofacies is observed.Hydrodynamic energy decreases basinward,leading to reduced thicknesses of tuff and sandstone deposits and increased accumulation of mudstone;(3)The paleomorphology,hydrodynamics and material source control fine-grained sedimentary lithology distribution with remarkable regularity.The typical rock phases in the deep lake area are thick mudstone interbedded with tuff and thick mudstone interbedded with thin layer of siltstone;Hydrodynamic regime governs the types of fine-grained lithofacies assemblages.The scale of their development is influenced by the strength of sediment supply.In addition,the nature of paleogeomorphic units affects water energy distribution and se-diment transport pathways,ultimately determining the spatial configuration of lithofacies assemblages.The experimental results provide a conceptual model of fine-grained deposition under deep-water conditions,of-fering valuable guidance for shale oil and gas exploration in the Chang 73 submember of the Yanchang For-mation in the Longdong area,Ordos Basin.关键词
细粒沉积/岩相分布/沉积模式/水槽实验/延长组/陇东地区/鄂尔多斯盆地Key words
fine-grained sediments/petrographic distribution/sedimentary pattern/flume experi-ments/Yanchang Formation/Longdong area/Ordos Basin分类
地质学引用本文复制引用
姜道广,罗顺社,陈亮,代榕,蒲宇新,周庆安,闫红果,庞锦莲..陇东地区延长组73亚段细粒沉积岩相分布规律及沉积模式:基于水槽沉积模拟实验[J].古地理学报,2025,27(3):625-640,16.基金项目
国家自然科学基金项目(编号:42102170)资助.Financially supported by the National Natural Science Foundation of China(No.42102170) （编号:42102170）
