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[1] Chinese loess-paleosol sequences undoubtedly have recorded geomagnetic events (both polarity reversals and excursions). However, the fidelity of the rapid paleomagnetic field oscillations during a polarity reversal remains uncertain. To test the reliability and consistency of the natural remanent magnetization records in Chinese loess, 10 subsets of parallel samples across the Matuyama-Brunhes (MB) reversal boundary were obtained from the Luochuan region in the hinterland of the Chinese Loess Plateau. Our paleomagnetic results show diversified virtual geomagnetic poles (VGPs) during the MB transition but consistent VGPs outside of the transitional zone. The anisotropy of magnetic susceptibility and rock magnetism results indicate that the sampled interval is rather uniform and undisturbed. The discrepancies of the characteristic remanent magnetization within the MB transition are probably due to the low efficiency in aligning magnetic grains, mainly pseudo-single-domain magnetite, associated with the low field intensity. Nevertheless, the stratigraphic location of the MB boundary can be confidently defined. Therefore, we conclude that Chinese loess-paleosol sequences can record geomagnetic reversal events, but the morphology within the polarity transition is rather questionable.

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Sediments from the continental shelf are sensitive to sea level, climatic changes, and local tectonic history. In this study, we carried out a high-resolution magnetostratigraphic investigation on the longest core (NHH01, 125.64 m) recovered from the South Yellow Sea (SYS). An abnormal interval dominated by negative inclinations was discovered by applying alternating field demagnetization (AFD) on samples from a greigite-bearing layer (44.90-51.80 m). In contrast, the inclinations of most greigite-bearing samples changed from negative to positive when heated to~360°C. This strongly indicates that this inclination anomaly revealed by the AFD alone is not a true negative subchron. After neglecting the effects of greigite-bearing layers, the straightforward correlation of the interpreted magnetostratigraphy defines the Matuyama-Brunhes boundary (781 ka) and the Jaramillo top (990 ka) at 68.64 m and 101.54 m, respectively. The linearly extrapolated basal age of the core is~1.10 Ma. In addition, several short-lived inclination anomalies can be tentatively assigned to magnetic excursions, which indicates that the sedimentation could be continuous even at the millennial time scale at depth intervals bracketing these fast geomagnetic events. Moreover, the excellent correspondence between clay content variations of the core and the marine oxygen isotope record indicates the potential of clay content as a paleoclimatic proxy in the studied region in the past~1 Ma. In brief, our study provides not only a robust age model in the SYS but also a methodological guide for paleomagnetic studies in continental shelf region.

The Pamir plateau forms a prominent tectonic salient that marks the western end of the Himalayan orogen containing several terranes that were accreted to Eurasia from the Late Paleozoic to Cenozoic. A detailed knowledge of the tectonic evolution of the Pamir salient during the Cenozoic is important for our understanding of the intracontinental deformation in the western Himalaya. Although the tectonic evolution of the Pamir salient has long been studied, the timing of collision between the Indian Plate and the Kohistan-Ladakh arc is still a matter of debate. We present new U-Pb ages and Hf isotopes of detrital zircons, magnetic fabrics, and stable isotopes from the foreland basin on the northeastern margin of the Pamir that indicate a change in sediment provenance started at about 47 Ma. Sediments in the southwest Tarim Basin were partially derived from the uplifted and eroded Karakoram and Kohistan terranes created by the collision between the Indian Plate and the Kohistan-Ladakh arc at circa 47 Ma, as a result of northward thrusting and propagation of the Indian Plate under Eurasia.

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