Effect of Fe–Ti oxides on Mo isotopic variations in lateritic weathering profiles of basalt

Validating the high-precision measurement of Mo isotopes at the 5 ng level using double spike MC-ICP-MS

“…However, these d 98/95 Mo values still fall within the range of À0.41-1.5&, which interpreted this observation as being controlled by redox conditions, organic matter, and atmosphere inputs. [54][55][56][57][58] The d 98/ 95 Mo of eighteen sediments ranges from À0.48& to 0.46& with an average value of 0.03 AE 0.27& (1SD, n ¼ 18), slightly lighter than that in loess from North China and upper continent crust (0.05-0.15&), [59][60][61] But its variation coefficient is large, different from the relatively homogenous Ni and Cr isotopes. 30,62 This observation suggests that Mo isotope composition in these sediments is heterogeneous, reecting the impact of various environmental factors demonstrated by .…”

A Review on the Elemental and Isotopic Geochemistry of Gallium

“…Bowen (1982) estimated an average Ga content of 21 ppm for 1,600 soil samples collected globally, with a range of 1-70 ppm, partially exceeding the crustal content of 15-19 ppm (Munir, 2018). Recent studies have shown soil Ga contents mainly within this range (Nuamah et al, 2019;Wang et al, 2020), which is not unexpected given the strong affinity of Ga with clay minerals, organic matter, and Fe-Mn hydroxides. Gallium is commonly enriched in residues of intense weathering, but with lower the Ga/Al ratios (Butler, 1953(Butler, , 1954.…”

Diagenesis Decreasing the Mo Isotopic Composition in Estuarine Systems: Implications for Constraining Its Riverine Input to Ocean

“…Reductive release of Mo during sediment diagenesis is a possible contributor to aqueous Mo in the estuary (Dalai et al., 2005; Gurumurthy et al., 2017). Mo demonstrates a robust affinity for Fe–Mn oxides under oxidizing conditions (Z. Wang et al., 2018, 2020); however, under reductive conditions at the sediment–water interface, unstable Fe–Mn oxides may release Mn, Fe, and Mo to the water column. Our surveys indicate that the dissolved oxygen levels in the bottom water in the upper (Humen part) and middle reaches of the PRE generally fall below 6.0 mg/L and markedly lower, often beneath than 3.0 mg/L, in the Guangzhou part (Table 1).…”

“…To understand the factors behind the temporal and spatial variations in the isotopic composition of particulate molybdenum (Mo), we studied the distribution of Mo in suspended particulates. This involved a three‐step sequential extraction from eight samples, targeting the Mo in exchangeable form within crystalline iron‐manganese (Fe‐Mn) hydroxides, and associated with organic matter (Marks et al., 2015; Siebert et al., 2015; Z. Wang et al., 2018, 2020; Wiederhold et al., 2007).…”

“…Liu et al., 2020; Neubert et al., 2011; Siebert et al., 2015; Voegelin et al., 2012; Z. B. Wang et al., 2015, Z. Wang et al., 2018, 2020).…”