| The Ordos basin is a large, non-marine sedimentary basin presently located in north-central China. During the Paleozoic and Mesozoic, the basin was located at the center of Asian continental assembly, and was a focused zone of deformation. Throughout its evolution, stress has been accommodated by deformation on the Ordos basin margins, while the interior has remained stable. Deformation of the margins generated narrow perimeter basins along the Triassic northwest and Jurassic northeast margins. The south and southwestern Ordos basin was a large subsiding Triassic-Jurassic foreland connected to a flat-laying Ordos basin interior, which remains undeformed with approximately 4 km of sedimentary fill.;In this study, detailed fluvial and lacustrine stratigraphy was used to create depositional frameworks for the perimeter sub-basins. Each was analyzed using the frameworks, available structural constraints and paleoclimate data. Previous studies of the northern Ordos sub-basins interpreted the basins as extensional half-grabens, which do not agree with their tectonic context. In this study, the data and interpretations of the sub-basins refine the previous interpretations, and (1) offer alternative scenarios of sub-basin development, (2) integrate the development scenarios of the sub-basins into the history of the larger Ordos basin, and (3) suggest a transtensional boundary along the northern Ordos basin.;On the south and west margins and the Ordos basin interior, observations and interpretations made in this study were used in conjunction with available published data. This study shows that a large lake formed in a foreland depression along the south and southwestern margins. It expanded to the northeast from the Late Triassic through the Middle Jurassic to occupy the southern half of the Ordos basin.;The detailed analyses of the basin margins and interior are used to develop a comprehensive understanding of the tectono-sedimentary evolution of an integrated Ordos Basin system. This study helps to constrain the Triassic-Jurassic tectonic setting for the Ordos basin within the evolution of the north China region during the early Mesozoic continental assembly of Asia. |
