Shanpin Liu

Loess plateau storage of northeastern Tibetan plateau-derived Yellow River sediment

Marine accumulations of terrigenous sediment are widely assumed to accurately record climatic- and tectonic-controlled mountain denudation and play an important role in understanding late Cenozoic mountain uplift and global cooling. Underpinning this is the assumption that the majority of sediment eroded from hinterland orogenic belts is transported to and ultimately stored in marine basins with little lag between erosion and deposition. Here we use a detailed and multi-technique sedimentary provenance dataset from the Yellow River to show that substantial amounts of sediment eroded from Northeast Tibet and carried by the rivers upper reach are stored in the Chinese Loess Plateau and the western Mu Us desert. This finding revises our understanding of the origin of the Chinese Loess Plateau and provides a potential solution for mismatches between late Cenozoic terrestrial sedimentation and marine geochemistry records, as well as between global CO2 and erosion records.

Late Tertiary reorganizations of deformation in northeastern Tibet constrained by stratigraphy and provenance data from eastern Longzhong Basin

The deformation of the Tibetan Plateau is central to unraveling the process and mechanism of continental tectonics. Although most agree that crust shortening and plateau growth were protracted throughout the Cenozoic Indo-Asian collision, particular deformation histories relating to tectonic kinematics and dynamics are still incomplete due to sparseness of diagnostic geological information from plateau margin. Here we present combined investigation of stratigraphy, magnetostratigraphy, and provenance for the eastern margin of Longzhong Basin to show two reorganizations of basin formation and tectonic regime during the late Tertiary. First, the depocenter migrated from the dispersed Paleogene sequences to the Wushan-Tianshui foreland sequence during the earliest Miocene (circa 22 Ma), accompanied by shift of sedimentary provenance from double sources including the eastern Qilian block and eastern West Qinling terrain to single source within the West Qinling. It suggests reorganization of deformation from NW-SE extension to NE-SW contraction and initial uplift of the eastern West Qinling. Second, massive coarse-grained fluvial beds were revived in the Wushan Basin during the late Miocene (circa 10 Ma), associated by eastward depositional expansion and another shift of sedimentary provenance toward northeast. It reflects thrusting up of the northern edge of the West Qinling and Liupan Shan Mountains linked with relocation of crust shortening from NE-SW direction to ENE-WSW direction and accelerated deformation of northeastern Tibet. These transitions of deformation regimes imply variation of geodynamic mechanisms during the process of plateau growth.

Rapid incision of the Mekong River in the middle Miocene linked to monsoonal precipitation

The uplift of orogenic plateaus has been assumed to be coincident with the fluvial incision of the gorges that commonly cut plateau margins. The Mekong River, which drains the eastern Qiangtang Terrane and southeastern Tibetan Plateau, is one of the ten largest rivers in the world by water and sediment discharge. When the Mekong River was established remains highly debated—with estimates that range from more than 55 to less than 5 million years ago—despite being a key constraint on the elevation history of the Tibetan Plateau. Here we report low-temperature thermochronology data from river bedrock samples that reveal a phase of rapid downward incision (>700 m) of the Mekong River during the middle Miocene about 17 million years ago, long after the uplift of the central and southeastern Tibetan Plateau. However, this coincides with a period of enhanced East Asian summer monsoon precipitation over the region compared with the early Miocene. Using stream profile modelling, we demonstrate that such an increase in precipitation could have produced the observed incision in the Mekong River. In the absence of an obvious tectonic contribution, we suggest that the rapid incision of the Tibetan Plateau and the establishment of the Mekong River in the middle Miocene may be attributed to increased erosion during a period of high monsoon precipitation.Incision of the Mekong River that occurred after the uplift of the Tibetan Plateau may have been driven by a period of high monsoon precipitation, as suggested by age data from river bedrock samples and stream profile modelling.

Corrigendum: Loess Plateau storage of Northeastern Tibetan Plateau-derived Yellow River sediment.

The original version of this Article contained errors in the Supplementary Information files: Zircon U-Pb age results for sample 23, shown in Supplementary Fig. 3, are incorrect, and missing from Supplementary Data 1, while several identification labels relating to Yellow River Lanzhou terraces samples are missing from Supplementary Data 2. Supplementary Data 1 and 2 have now been updated to provide the missing information, while the corrected version of Supplementary Fig. 3 appears below.