海洋地质前沿2025，Vol.41Issue(12)：42-53,12.DOI:10.16028/j.1009-2722.2024.219
鲁西地区早二叠世低可容空间浅水三角洲发育演化过程及聚煤机制
Evolution and coal accumulation in the Early Permian low-accommodation shallow-water delta in the Luxi region
摘要
Abstract
The development of low accommodation delta sequences and their coal-formation and mechanisms have increasingly attracted attention.Previous studies focused on the characteristics and mechanisms of coal-form-ation from the perspective of accommodation changes,while there has been less research on the relationship between the development and evolution of shallow water deltas and coal formation.The Lower Permian Shanxi Formation in the Luxi(western Shandong Province)region was studied in terms of the development and evolu-tion of shallow water deltas and their impact on coal formation.Based on detailed outcrop and core logging of lithofacies and vertical sequences,distributary channels,tide-influenced distributary channels,interdistributary bays,peat swamps,and other delta plain environments,as well as delta front environments such as mouth bars and tide-influenced mouth bars,and prodelta environments,were identified.By comparing single-well and multi-well sedimentary cycles,the shallow water delta sequences could be divided into five depositional cycles:C1-C5,each showing a sub-cycle of progradation-retrogradation-progradation under the background of overall progradation.By integrating the analyses on the delta deposition and coal-formation,we believed that the water dynamic zoning and delta evolution controlled the coal-formation.Results indicate that under the background of low-accommoda-tion space and gentle terrain,the auto-cycle and allo-cycle of the delta jointly controlled the development and coal-formation in the delta.The migration of delta distributary channels caused differences in water dynamic condi-tions,which controlled the coal-forming environment and coal-seam development characteristics.In the river-dominated area,coal-formation was mainly developed in inter-channel swamps and interdistributary bays,where coal seams were relatively dispersed and limited.In the tide-dominated area,coal-formation was mainly in tide-in-fluenced peat swamps with wide distribution and large thickness.The transgression-regression cycle controlled the overall distribution trend of coal seams and a large amount of peat swamps were formed during the regression period when plants thrived and consequently were rapidly buried and coal-bed formed during the transgression period.The above mechanism of coal formation in shallow water deltas provided a reference for the exploration of coalbed gas in the Upper Paleozoic in the North China region.关键词
浅水三角洲/河流作用/潮汐作用/聚煤作用Key words
shallow water delta/fluvial action/tidal action/coal accumulation分类
海洋科学引用本文复制引用
鞠磊,贾海波,刘海燕..鲁西地区早二叠世低可容空间浅水三角洲发育演化过程及聚煤机制[J].海洋地质前沿,2025,41(12):42-53,12.基金项目
国家自然科学基金"东营凹陷沙三中三角洲-深湖重力流体系'源-汇耦合'的成因机制"(41672100) （41672100）
