南华北盆地中东部山西组物源特征OA北大核心CSTPCD

The southern North China Basin is located in the southeastern North China Craton,at the junction of the North China and lower Yangtze plates.Investigating the provenance system is crucial to gain a deeper under-standing of the sedimentary pattern in this region.Focusing on the sandstones,siltstones,and mudstones in the Shanxi Formation in three wells drilled in the central part of southern North China Basin,this study conducted petrological and geochemical analyses of marine-continental transitional clastics in this formation.Using petrologi-cal and geochemical characteristic parameters,this study determined the provenance areas of the clastics and their tectonic settings.The results indicate that:1)both trace and rare earth elements exhibit relatively higher sensitiv-ity than major minerals in research into the provenance of marine-continental transitional clastics.2)Shanxi For-mation in the study area features a near-source,freshwater,neritic sedimentary environment that ranges from dys-oxic to oxygen-rich and from weakly reducing to weakly oxidizing conditions.3)This formation features a variety of sedimentary provenance areas.Sediments in the area originate primarily from uplifted continental island arcs,along with contributions from uplifted active continental margins and ancient passive continental margins.4)The Qinling-Dabie orogenic belt to the south serves as the provenance area of the clastics in the Shanxi Formation in the study area.The southern part of study area can be dated back to the early stage of the arc-continent collision,with primary provenance areas including continental island arcs and active continental margins.In contrast,the western part of the study area is formed in the late stage of the arc-continent collision.For its seaward side,the primary provenance areas consist of continental island arcs.For its landward side,the provenance areas prove to be a small number of uplifted paleo-passive continental margins of the North China Craton.