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The anisotropy of magnetic susceptibility (AMS) has great potential in deciphering weakly deformed fabrics that may be related to tectonic stress. Previous studies have suggested that magnetic lineation is a good indicator of paleostrain direction. It is unclear whether the magnetic fabric can also be used to indicate the present‐day strain field. To verify this idea, we measured the AMS of freshly consolidated lacustrine fine‐grained sediments at 11 locations in the Qaidam and Chaka‐Gonghe basins of the northeastern Tibetan Plateau and compared it with the present‐day strain field deduced from the global position system (GPS) velocity field. The magnetic lineations of both room‐temperature and low‐temperature AMS are roughly perpendicular to the GPS‐derived tectonic shortening direction within the error range, suggesting that the AMS of freshly consolidated muds is an effective indicator of the present‐day strain field, even if the sediments appear undeformed at the outcrop scale. Plain Language Summary: Knowledge of the present‐day crustal stress field is important for understanding seismic activity and plate tectonics. Earthquake focal mechanisms and borehole breakouts are the traditional methods used to investigate the present‐day stress field. The former depends on the frequency of seismic activities, the magnitude, and the location of each earthquake, none of which can be controlled or adjusted. The latter is time‐consuming and laborious. Magnetic fabric is an economical, rapid, and sensitive indicator of paleostrain. If the magnetic fabric of recently deposited mudstone is measurable, anisotropy of magnetic susceptibility (AMS) has the potential to be used to investigate the present‐day stress. In this study, we compared the magnetic fabric of freshly consolidated lacustrine mudstones with the present‐day stress field derived from traditional stress indicators and found a rough consistency between them. This suggests that magnetic fabric can be used as an indicator of the present‐day stress field, which will add much more new data to the world stress database. Key Points: The freshly consolidated fine‐grained lake sediments in the northeastern Tibetan Plateau record a weakly deformed fabricMagnetic lineations of freshly consolidated muds in the Qaidam and Chaka‐Gonghe basins are roughly consistent with global position system‐derived strain fieldThe magnetic fabric of the freshly consolidated mud deposited in still water is an effective indicator of the present‐day strain field [ABSTRACT FROM AUTHOR]

The modern high topography of the eastern Tibetan Plateau is drained by several of the largest rivers on Earth, and exerts a prominent influence on the Asian monsoon pattern. However, when the high terrain was formed remains highly debated. Here, we present detrital zircon U‐Pb ages that indicate a south‐flowing drainage system with distal headwaters passed through the Ninglang Basin at ca. 45 Ma. We advocate for early–middle Eocene surface uplift in the Gonjo Basin and areas to the west creating a southeast tilted topography across eastern Tibet. The termination of sedimentation at ca. 40 Ma implies that the river system had deviated from the Ninglang Basin, which we interpret as a result of rise of the Yalong‐Yulong thrust belt. Combined with other lines of evidence from previous studies, we support the establishment of moderate‐high elevation topography of eastern Tibet by late Eocene time. Plain Language Summary: The eastern Tibetan Plateau has been a hotspot for studying the interactions between tectonic uplift, monsoon evolution, Asian biodiversity, and topographic development during continental collision. However, the timing of high‐elevation topography formation in eastern Tibet is a matter of debate, with age estimates ranging from middle Eocene to late Miocene. This directly leads to contradictory understanding of uplift processes and plateau growth mechanisms. Sedimentary basins are excellent recorders of past drainage pattern and tectonic process, while many Cenozoic basins in eastern Tibet have been understudied. Here we focus on the Ninglang Basin and carry out comprehensive research including stratigraphy, sedimentology, chronology, and provenance analysis. We indicate that the Ninglang Basin was mainly supplied by a south‐flowing exterior drainage system during the middle Eocene, implying the existence of a regional, low‐gradient landscape beveling to the southeast at that time. The extinction of this drainage system in late Eocene time likely means the initiation of the Yalong‐Yulong thrust belt, a major boundary fault system in eastern Tibet. Our study thus support that the topography of eastern Tibet has been elevated in the late Eocene. Key Points: A large‐scale, south‐flowing fluvial system drained through the Ninglang Basin during the middle EoceneThe demise of the Ninglang Basin in the late Eocene resulted from the uplift of the Yalong‐Yulong thrust beltThe elevated terrain of eastern Tibet was initially formed in the late Eocene [ABSTRACT FROM AUTHOR]

The uplift and deformation styles of the Tibetan Plateau have been long debated on stepwise growth and crustal channel flow. Here, we offer new insight into this issue by constraining the pulsed exhumation history of the Yalong thrust belt in eastern Tibet, using apatite and zircon (U–Th)/He data from three ∼1 km vertical transects. The results revealed two rapid cooling pulses in the Late Oligocene (∼24 Ma, 50°C/m.y.) and the Middle Miocene (17–14 Ma, 35 °C/m.y.), respectively, which we ascribe to the staged‐thrusting faulting of this belt. These thrust faulting events indicated upward and eastward growth of the Tibetan Plateau, further suggested that the high topographic relief across the Yalong thrust belt mainly formed (at least) since the Late Oligocene. The available documents from paleoaltimetry, basin sediment accumulation, and thermochronometers and our new results reveal a regional‐scale stepwise propagation pattern of tectonic deformation during the Middle–Late Cenozoic in eastern Tibet. Plain Language Summary: The role of faulting in crust thickening has been one of the main controversies in the formation and evolution of the Tibetan Plateau. The Yalong thrust belt in eastern Tibet is a major Cenozoic structure with a 1.8–2.4 km topographic step, and its deformation processes are closely associated with the Cenozoic eastward plateau growth. In this study, we report 79 apatite and 78 zircon (U–Th)/He (AHe and ZHe) ages of 26 granitoid samples from three ∼1 km vertical transects. We suggest that the Yalong thrust belt underwent two rapid cooling (exhumation) pulses in the Late Oligocene (∼24 Ma, 50°C/m.y.) and the Middle Miocene (17–14 Ma, 35°C/m.y.), respectively. These pulses of exhumation and uplift along the Yalong thrust belt contributed to the development of the current morphology across eastern Tibet. Integrating previous findings and those reported in our study allow us to propose a regional‐scale stepwise propagation pattern of tectonic deformation during the Middle–Late Cenozoic in eastern Tibet. We suggest that the dynamic development of the deformation pattern may have been driven by the northward indentation of the Eastern Himalayan Syntaxis and the consequent lower crustal flow into southeastern Tibet. Key Points: The Yalong thrust belt underwent two rapid cooling pulses in the Late Oligocene (∼24 Ma) and Middle Miocene (17–14 Ma)The topographic relief across the Yalong thrust belt is mainly the result of pulsed thrusting at least since 24 MaA regional‐scale stepwise propagation pattern was proposed for the Middle–Late Cenozoic tectonic deformation in eastern Tibet [ABSTRACT FROM AUTHOR]

Previous studies suggest that the northeastern Tibetan Plateau has been the major source area for the Chinese Loess Plateau (CLP); this contribution was used to prove that the Yellow River played a dominant role in transporting the materials from the northeastern Tibetan Plateau, making them available for the CLP. Accordingly, the proximal North China Craton is considered to have increased supply potential of dust to the CLP further eastward. However, the origin of the eastern CLP and the relationship between loess and proximal river sediments have never been systematically studied, which prevents us from working out the surface process between source and sink. In this study, we conducted U–Pb dating and analyses of the grain morphologies of detrital zircons and heavy mineral assemblages on the upper Quaternary loess and riverbed sediments on the eastern and central CLP. We also built a data set (n = 48,161) of the zircon U–Pb ages of the Quaternary loess, deserts, and potential source areas. Our results show that most loess samples on the eastern CLP were strongly affected by the North China Craton. The dust supply ability of rivers to loess is very limited. Along the dust transport path, the proximal mountains, rivers and loess can all provide dust for loess deposition. Our findings emphasize the important role proximal supply has played in the evolution of the CLP since at least the late Neogene, for example, the northeastern Tibetan Plateau for the western and central CLP, and the North China Craton for the eastern CLP. Plain Language Summary: Understanding the dust source of the Chinese Loess Plateau (CLP) provides fundamental knowledge about Cenozoic changes in the tectonics of the northeastern Tibetan Plateau and in the East Asian climate. For the eastern CLP, which has been poorly studied by scholars, we present a provenance study of detrital zircons, showing that most upper Quaternary loess samples mainly originated from the proximal North China Craton, and a few samples mainly originated from the northeastern Tibetan Plateau + Central Asian Orogenic Belt, indicating spatial heterogeneity. The river sediments show a weak impact on loess deposits. We emphasize the urgency of reassessing the dust contribution of the farmost source areas such as the Taklimakan Desert and Gurbantunggut Desert to the CLP. Key Points: The dust supply ability of rivers to loess is limitedThe geomorphic units along the dust transport path can provide dustThe important role of proximal supply in loess deposition in all parts of the Chinese Loess Plateau is emphasized [ABSTRACT FROM AUTHOR]

The distinctive right-angled bend of the Yellow River around the Ordos Block, a large Permo-Mesozoic continental block in East Asia, has attracted much attention from geomorphologists and geologists concerning its formation and evolution for more than a century. The Jinshaan Gorge, an over 600 km long entrenched reach of the Yellow River, currently connecting the Hetao Graben to the north and the Weihe Graben to the south, is considered to have developed in very recent geological time. However, the timing and processes of drainage integration between the two grabens and formation of the Jinshaan Gorge as a deeply incised form are still under debate, owing to limited data and various interpretations of them. In order to better understand the geomorphological evolution of the Yellow River, we investigated the sedimentology, magnetostratigraphy, and detrital zircon U-Pb dating in the upper Neogene and Quaternary deposits along the Jinshaan Gorge. We further integrated the new data with the sedimentary record of the adjacent basins in the northeastern Tibetan Plateau (NTP) and the basins around the Ordos Block, as well as the incision history of the Yellow River inferred from its terrace sequence. We show that the upper Neogene alluvial sediments preserved in the broad Tangxian valley along the Jinshaan Gorge are a mixture of materials from the Lvliang Shan and the Ordos Block. Importantly, they share almost the same provenance and zircon age spectra with the Pleistocene and Holocene Yellow River deposits. The broad Tangxian valley commenced incision during the Late Pliocene, followed by the formation of two Early Pleistocene terraces dated to ~2.2 Ma and ~1.2 Ma. The incision of the Yellow River and the accumulation in the basins were characterized by steady and slow rates before the Late Pleistocene, but an acceleration thereafter. We propose a three-stage evolutionary model for the development of the Yellow River, controlled by changing tectonics and climate during the Neogene. Before the late Miocene, an endorheic river system was developing in the Longzhong Basin. From the late Miocene to Early Pliocene, the Yellow River developed the current drainage system from the Longzhong Basin to the lower reach, constrained by the topographic pattern of the Ordos Block and its periphery, in turn controlled by coeval tectonic movements. Since the Late Pliocene, the Yellow River has undergone rapid incision with integration of the upper reach in the NTP and entrenchment in the upper and middle reaches, which were controlled by the continuously rising NTP and a deteriorating climate. The Tangxian valley developed and was filled between the end of the Miocene and Pliocene, approximately 8 to 3 Ma, and it was abandoned in the Late Pliocene in response to important climatic variations. The next acceleration in both incision and subsidence around the Ordos Block in the Late Pleistocene was also coeval with strong climatic oscillations, suggesting a possible link between climate and tectonics in the Neogene entrenchment history of the Yellow River. [Display omitted] • Two Early Pleistocene terraces were dated to ~2.2 Ma and ~1.2 Ma. • The Yellow River developed the current drainage system since the late Neogene. • The entrenchment was controlled by the rising NTP and the deteriorating climate. • The broad Tangxian valley developed between 8 and 3 Ma. • The recent accelerated incision was controlled by changing climate and tectonics. [ABSTRACT FROM AUTHOR]