Triassic evolution of source-to-sink drainage systems in the North Ordos Basin of central China: Impact of asynchronous uplift history

A pattern of asynchronous uplift influenced drainage reorganization in the North Ordos Basin (NOB) of central China in Triassic times. In this study, the source-sink system of the NOB was reconstructed, and the source area was identified, based on an analysis of petrology, geochronology, and palaeocurrent direction analysis, offering a new perspective on the interaction between deep tectonic processes and surface responses in the northern part of the North China Block (N-NCB). Our zircon age data reveal three prominent peaks for the Palaeoproterozoic, Mesoproterozoic, and Upper Palaeozoic, suggesting that the N-NCB may have acted as the source area for the NOB. During the Late Triassic interval, increased zircon ages (1500–1800 Ma) indicate an enhanced influx of detrital material from the central N-NCB. Furthermore, analysis of thin sections and petrographic modal compositions indicates a change in source areas from solely recycled orogenic sources to a combination of recycled orogenic and magmatic arc sources. The youngest zircon ages (∼233.6 Ma) from the tuffaceous siltstone mark this transition, with palaeocurrent data supporting a change in the source area from the western to the central N-NCB after this time. This transition underscores the impact of the asynchronous uplift of the N-NCB on the source-to-sink system of the NOB, providing an innovative perspective for reconstructing the southward subduction process of the Okhotsk Plate and associated back-arc extension along the N-NCB.