Hydrogeochemical mechanism of Li-Cs-rich thermal springs in the Karakoram Fault, Qinghai-Xizang Plateau: New insights from multiple stable isotopes.

High lithium (Li) and cesium (Cs) concentrations in the Qinghai-Xizang Plateau thermal springs pose environmental and health challenges, but their origins and enrichment mechanisms remain unclear. This study focuses on the Sogdoi geothermal field, located along the southern Karakoram Fault, to investigate these processes. Multi-isotope analyses (H, O, Li, Sr) reveal that Li and Cs predominantly originate from the host rocks, especially granitoids and meta-sedimentary rocks, rather than from magmatic fluids.

Ice sheet expansion in the Cretaceous greenhouse world.

Globally elevated temperatures during the Cretaceous extreme greenhouse climate interval were punctuated by the Valanginian cooling event, which was characterized by a positive carbon isotope excursion, global cooling, and a glacial event approximately at 135 Ma. Disentangling ocean temperature and continental ice volume trends enables us to better understand climate fluctuations over deep time. We investigated the ocean temperature-ice sheet dynamics of glaciation events that occurred in the Cretaceous greenhouse world.

A distinctive Eocene Asian monsoon and modern biodiversity resulted from the rise of eastern Tibet.

The uplift of eastern Tibet, Asian monsoon development and the evolution of globally significant Asian biodiversity are all linked, but in obscure ways. Sedimentology, geochronology, clumped isotope thermometry, and fossil leaf-derived numerical climate data from the Relu Basin, eastern Tibet, show at ∼50-45 Ma the basin was a hot (mean annual air temperature, MAAT, ∼27 °C) dry desert at a low-elevation of 0.6 ± 0.

A Simplified Method Using a Single N,N,N',N'-Tetraoctyl Diglycolamide Resin Column for the Purification of Sr, Nd and Hf in Geological Materials and the Determination of Their Isotopic Ratios by Multi-collector Inductively Coupled Plasma-Mass Spectrometry.

A simplified method using a single column of N,N,N',N'-tetraoctyl diglycolamide (TODGA) resin is developed for the separation of Sr, Nd and Hf with matrix and interference elements from geological samples, and for subsequent determination of their isotopic ratios by multi-collector inductively coupled plasma-mass spectrometry (MC-ICP-MS). The analytes of Sr, Nd and Hf are absorbed by the TODGA resin and eluted with 6 mol/L HNO, 1.2 mol/L HCl and 1 mol/L HNO-1.