Rare earth element and strontium isotope geochemistry in Dujiali Lake, central Qinghai-Tibet Plateau, China: Implications for the origin of hydromagnesite deposits

Magnesium Isotope Constraints on the Holocene Hydromagnesite Formation in Alkaline Lake Dujiali, Central Qinghai‐Tibetan Plateau

“…The Sr isotope data of water samples discussed in the present study were previously reported in Lin et al. (2019a). Since Mg isotopes were measured on the same samples, the data is discussed again in the context of the new Mg isotope data in the present study.…”

“…The representability of the sampled stream and groundwaters for supplying solutes to the lake can be assessed with Sr isotopes (Lin et al., 2019a; Figure 4b). Streams and groundwaters have a considerable range in $${}^{87}\mathsf{S}\mathsf{r}/{}^{86}\mathsf{S}\mathsf{r}$$ ratios between 0.709 and 0.711 (Table S2 in Supporting Information S2).…”

“…DL is located in the central Qinghai-Tibet Plateau (QTP; Figure 1, China, 4,524 m above sea level) (Lin et al, 2017(Lin et al, , 2019a(Lin et al, , 2019b. It formed as a subsiding sub-basin located within a larger Cenozoic faulted basin that comprises neighboring Lake Selin Co (Siling Lake or Qilin Lake, the largest lake in Tibet).…”

“…Mg isotopes are an emerging geochemical tracer that are known to fractionate during precipitation of carbonates and silicates from aqueous fluids, and are thus useful for quantifying carbonate precipitation processes (Harrison et al., 2021; Hindshaw et al., 2020; Li et al., 2012; Mavromatis et al., 2021; Oelkers et al., 2018; Tipper, 2022; Tipper et al., 2006a, 2008). In this study, we present Mg isotope data ($$\delta {}^{26}\mathsf{M}\mathsf{g}/{}^{24}\mathsf{M}\mathsf{g}$$ expressed as $$\delta {}^{26}\mathsf{M}\mathsf{g}$$ in per mil units) and Mg/Ca data on lake waters, incoming stream and groundwaters, lake sediments, and related hydromagnesite in the well‐studied alkaline Dujiali Lake (DL) in Tibet (Lin et al., 2017, 2019a, 2019b), and compare these to global databases of waters and other alkaline lakes where hydromagnesite forms. DL is undersaturated with respect to hydromagnesite in the present day, but in the recent past (Holocene), substantial volumes of hydromagnesite have been deposited from DL.…”

Mg-Rich Authigenic Carbonates in Coastal Facies of the Vtoroe Zasechnoe Lake (Southwest Siberia): First Assessment and Possible Mechanisms of Formation

“…Numerous examples of modern Mg-carbonate formation under conditions of playas and saline continental lakes were reported for various arid and semi-arid regions of the world [12,14,15,[31][32][33][34][35][36][37][38][39][40][41][42][43][44][45]. The majority of such environments are evaporitic and/or alkaline [12], which is most often related to specific climatic conditions and the specific geology of territories where such phenomenon appear.…”