Provenance study from petrography and geochronology of Middle Jurassic Haifanggou Formation in Xingcheng Basin, western Liaoning Province

Abstract

In recent decades, the Yanshanian movement in the Mesozoic has been a hotspot of much geological research, attracting numerous studies focusing on regional tectonics, basin evolution, and associated magmatism and volcanic activities. The Haifanggou Formation, exposed in Xingcheng Basin, which is one of intracontinental basins in western Liaoning Province, North China Craton (NCC), comprises mainly conglomerates dominated with interbedded sandstone. Although palaeontology, stratigraphy and lithofacies have been established, its mineralogical compositions and geochronology, even the provenance and implications for Yanshanian movement are still poorly discussed. Available sandstone samples provided a unique opportunity to study the genesis and further deciphered the tectonic mechanisms. The sandstone types of Haifanggou Formation are dominantly litho‐feldspathic litharenite and litharenite. Modal sandstone analysis shows that the origin and deposition mainly are due to arid to semi‐arid weathering and recycling of older rocks and magmatic arcs, eroded and transported debris from eastern NCC. Our new detrital zircon U–Pb ages exhibit that the maximum depositional ages of the Haifanggou Formation were conservatively estimated as late Middle Jurassic (165.6 ± 3.1 Ma). The detrital zircon U–Pb age spectrum of this formation is dominated by several peaks that indicate a provenance from the surrounding rocks including the basement of NCC. The sedimentation of the Haifanggou Formation is deposited under compressional tectonics as a local response of the Yanshanian movement which was related to the subduction of Palaeo‐Pacific Plate.