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A high-precision and high-resolution vertical velocity for the Chinese mainland is obtained by integrating precise levelling and Global Navigation Satellite System data, using a Helmert joint adjustment method. The results show that the surface vertical rates range between −3.0 and 3.9 mm yr−1 with continuous deformation in most areas, except the obvious subsidence at the rates of −15.0 to −94.2 mm yr−1 induced by groundwater exploitation in the North China Plain. Particularly, the central and southern Tibet, Tien Shan, Alashan, Ordos, eastern Cathaysia and Northeast China uplift at the rates of 0.5–3.9 mm yr−1; the southeastern Tibetan Plateau, Sichuan basin and Yangtze block are dominated by surface subsidence at the rates of −3.3 to −0.5 mm yr−1. Furthermore, the vertical rates vary little between the eastern and western regions of the Chinese mainland despite their pronounced differences in horizontal deformations. The effects of gravity isostasy and non-tectonic factors, including the environmental mass loads, Glacier Isostatic Adjustment (GIA), poroelastic expansion/compression, and mining operations have partially contributed to the vertical deformation of the Chinese mainland. Overall, this velocity reflects the complicated deformation features induced by the multiple geodynamic processes of the Chinese mainland. These geodynamic processes include isostasy, orogenic processes and geothermal anomalies associated with slab subduction/plate collision. [ABSTRACT FROM AUTHOR]

The Ailaoshan shear zone developed plenty of Cenozoic granitic plutons, located between the Yangtze block in the east and the Simao block in the west. Although a mass of previous studies have enriched the understanding of petrogenesis of these plutons, there are few reports on the plutons within the Mojiang-Lvchun terrane, a suspect domain between the Yangtze and Simao blocks. Among two plutons investigated in this paper, the Fenshuiling pluton is characterized by strongly shoshonitic (K20 = 5.8–6.4 wt.%) nature, high Y (6.5–30.0 ppm) and Yb (0.88–2.97 ppm) contents, and has limited variations in La/Yb (8.6–20.5) and Dy/Yb (1.6–1.9) with increasing SiO2. In Mengha, the pluton is also strongly shoshonitic (K20 = 5.7–6.1 wt.%), high Y (18.7–32.3 ppm) and Yb (2.03–3.50 ppm) contents, and shares limited variations in La/Yb (17.0–17.6) and Dy/Yb (1.5–1.7) with increasing SiO2. These tendencies correspond with the differentiation from a shoshonitic mafic melt by olivine, clinopyroxene and plagioclase (gabbroic) dominated fractional crystallization. These plutons mainly composed of quartz syenites are characterized by island-arc basalt (IAB) patterns, which are consistent with those evolved by shoshonitic mafic melt derived from metasomatic lithospheric mantle within the Yangtze block. Zircon εHf(t) values of Fenshuiling and Mengha plutons range from −4.1 to −0.7 and −2.8 to −1.1, respectively, and their whole-rock εNd(t) values are −5.0 to −4.6 and −4.7 to −4.6, respectively. These Hf isotopes are similar to those from Neoproterozoic granitoids caused by a persistent Neoproterozoic subduction around the southwestern margin of the Yangtze block. This similarity supports a scenario that the enriched lithospheric mantle source area of these plutons caused by the Neoproterozoic subduction, also means that the suspect terrane belongs to the Yangtze block. The location of the Fenshuiling and Mengha plutons separated from those within the western margin of the Yangtze block is attributed to Cenozoic sinistral shearing events. [ABSTRACT FROM AUTHOR]