The Pacific meridional overturning circulation is thought to have a significant influence on global climate. However, the extent to which intermediate and deep circulations have changed in the Pacific Ocean since the Last Glacial Maximum (LGM) is not well known. At present, the South China Sea Deep Water (SCSDW) is fed by the upper Pacific Deep Water. Here we present new benthic foraminiferal δ¹³C and redox‐sensitive elemental data from a sediment core retrieved from the southern deep SCS to reconstruct the oxygenation history of the SCSDW since the LGM. Oxygenation records from the deep SCS and intermediate and deep waters in the Pacific Ocean demonstrate that the SCSDW deeper than 1,600 m has been sourced by the Pacific Deep Water since the LGM. Our data suggest that the well‐ventilated North Pacific Intermediate Water would not have influenced the SCSDW during cold stadials of the last deglacial period.

During the Mesozoic, Southeast (SE) Asia (including South China and the South China Sea (SCS)) was located in a transitional area between the Tethyan and Pacific geotectonic regimes. However, it is unclear whether geodynamic processes in the SE Asian continental margin were controlled by Tethyan or paleo-Pacific Ocean subduction. Herein, we report ~124 Ma adakitic granodiorites and Nb-enriched basalts from the Xiaozhenzhu Seamount of the SCS. Granodiorites have relatively high Sr/Y (34.7–37.0) and (La/Yb)_N (13.8–15.7) ratios, as well as low Y (9.67–9.90 μg/g) and Yb (0.93–0.94 μg/g) concentrations, typical of adakites. Their Sr/Y and (La/Yb)_N values coupled with their relatively low initial ⁸⁷Sr/⁸⁶Sr ratios (0.70541–0.70551), relatively high K₂O contents (3.31–3.38 wt%), high Th/La ratios (0.33–0.40), negative ε_Nd(t) values (−3.62 to −3.52), and their variable zircon ε_Hf(t) values (−3.8 to +5.2) indicate that these rocks were formed by melting of subducted oceanic crust and sediments. The Nb-enriched basalts show enrichment in high field strength elements (HFSE) and have ε_Nd(t) values of +2.90 to +2.93, as well as relatively low initial ⁸⁷Sr/⁸⁶Sr ratios of 0.70341–0.70343, demonstrating that they were derived from a depleted-mantle (DM) source metasomatized by silicate magmas originating from melting of a subducted oceanic lithospheric slab. By combining our findings with data from other Late Mesozoic arc-related magmatic rocks and adakites from the broader study area, we propose a geotectonic model involving subduction of young oceanic lithosphere during the Late Jurassic and northward subduction of the proto-South China Sea (PSCS) along the SE Asian continental margin during the Early Cretaceous. This conceptual model better explains the two-period Mesozoic magmatism, commonly reported for the SE Asian continental margin.

Recent high‐velocity rotary shear experiments results show that spherical nanoparticles can reduce fault friction dramatically during seismic slip. But questions like what are the roles of the nanoparticles in the whole slip are largely open problems. In this study, two types of nanoparticles were found in the Red River fault zone, including agglomerated nanoparticles in the ductile shear zone and spherical nanoparticles adjacent to the brittle faults. To ascertain the formation of these nanoparticles and explore the role of nanoparticles, the experiments under high temperature and pressure were conducted. The results of the experiments and of the previous studies suggest that the spherical nanoparticles can produce at the low temperature, which may lubricate the fault and significantly reduce the dynamic coefficient of friction. With the rise in temperature, the spherical nanoparticles are elongated or deformed to the agglomerated nanoparticles, which may no longer lubricate the fault, and lead the fault slip to slow down until it stops. Accordingly, this paper summarizes the role of these nanoparticles throughout the whole process of fault sliding.