Depositional and diagenetic processes in volcanic matrix‐rich sandstones from the Shanxi and Shihezi formations, Ordos Basin, China: Implication for volcano‐sedimentary systems. (15th July 2022)

• Record Type: Journal Article
• Authors: Cui, Hang; Zhu, Shifa; Tan, Mingxuan; Tong, Huan
• Is Part Of: Basin research. Volume 34:Number 6(2022)
• Page Start: 1859
• Page End: 1893
• Publication Date: 2022-07-15
• Subjects: hyperpycnal flow -- Ordos Basin -- paragenetic sequence -- provenance area -- volcanic matrix‐rich sandstone -- volcanogenic materials; Sedimentation and deposition -- Periodicals; Sedimentary basins -- Periodicals; 551
• DOI: 10.1111/bre.12688
• Languages: English
• ISSNs: 0950-091X

Abstract

Abstract: Volcanic eruptions can provide large amounts of sedimentary materials and expose fluvial valleys or lakes to catastrophic hyperpycnal flood events, but this process has not been documented in detail. The Ordos Basin Permian fluvio‐deltaic system reveals evidence for abundant volcanism linked to the tectonic evolution of orogenic belt around the basin and provides a 'natural laboratory' for investigating hyperpycnal flows associated with volcanic activity. This study analysed volcanic matrix‐rich sandstone (VMS) samples for petrology, mineralogy and geochemistry in order to address current and uncertain volcanogenic material provenance explanations and the lack of systematic investigations into the depositional and diagenetic processes of volcanic related sediments in the southwestern basin. By combining tectonic background surveys, detrital zircon geochronology and spatial distribution of volcanogenic materials, it was found that volcanogenic materials were not derived from the Yinshan‐Yanshan Orogenic Belt (YYOB) as previously thought, but instead evidence a southwestern origin from the North Qinling Orogenic Belt (NQOB). Volcanogenic materials retained in the provenance area during frequent volcanic eruptions were transported to the basin via fluvial systems shortly after the eruption. The associated sediments meet the criterion for hyperpycnites based on lithofacies associations, suggesting the occurrence of hyperpycnal flows during the deposition of VMS. During the subsequent burial stage, the VMS became three distinct types defined by their volcanic matrix content and have similar paragenetic sequences but different diagenetic intensities. The differing content of authigenic minerals in the three types was closely related to the sandstone pore structure characteristics and the evolution of volcanic‐matrix alteration materials. This article proposes a possible explanation for the previously unidentified tectonothermal events in the NQOB during the Permian, validating and reinforcing the theoretical work of hyperpycnal flow. This contribution provides new insights and understanding of the depositional and diagenetic processes of lacustrine basins with similar tectonic settings. Abstract :