... ocean circulation and chemical inventories . Earth and Planetary Science Letters , 76 , 135 – 150 , doi: 10.1016/0012-821X(85)90154-2 10.1016/0012-821X(85)90154-2 Bradbury , H.J. and Turchyn , A.V. 2018 . Calcium isotope fractionation in sedimentary pore fluids from ODP Leg 175...

...: 10.5194/bg-10-6375-2013 . Zhou, X., Rosenthal, Y., Haynes, L., Si, W., Evans, D., Huang, K.-F., Hönisch, B., and Erez, J. 2021 , Planktic foraminiferal Na/Ca: A potential proxy for seawater calcium concentration : Geochimica et Cosmochimica Acta...

... investigated the effects of adding calcium chloride (CaCl 2 ) and using EKS techniques on the soil shear characteristics (shear strength and its two components: cohesion and internal friction angle) of three different soil layers in collapsing gullies. The results showed that the EKS techniques significantly...

... the global carbon cycle. Recent studies of calcium isotopes (δ 44/40 Ca) in shallow-water carbonates indicate that δ 44/40 Ca can be altered during early marine diagenesis, implying that δ 13 C may also potentially be altered. Here, we tested the hypothesis that the platform carbonate δ 13 C record...

... ( Anenburg et al., 2020a , 2022 ; Yuan et al., 2023 ). Some carbonatites, however, exhibit initial magmatic deposition of REE phases ( Wall and Mariano, 1996 ; Zaitsev et al., 2002 ; Weng et al., 2021 ; Zheng et al., 2023 ) or REE sequestration by calcium minerals (e.g., apatite; Bühn, 2001...

...Alexander J. Krause; Graham A. Shields; Robert J. Newton; Benjamin J. W. Mills Abstract Understanding the long-term variations in seawater sulfate concentrations ([SO 4 2− ] sw ) is crucial to our understanding of the dynamic relationships between the sulfur, carbon, calcium and oxygen cycles...

... portion of each ablation profile was selected in order to exclude any surface contamination and artifacts of beam penetration (Fig. A1). International reference materials from the USGS (MACS-3 synthetic calcium carbonate) and NIST (SRM 610 and 612 silicate glasses), were used for calibration and quality...

..., the resulting high potassium level actively promotes the illitization of feldspars ( Alekseyev et al. 1997 ; Zhu and Lu 2009 ). With the accumulation of calcium (or magnesium or sodium) in the system, swelling clays such as montmorillonite can be formed. In addition to weathering, hydrothermal alteration...

...) are listed in Table 1 . Raw CLN is rich in potassium and calcium and has a SiO 2 /Al 2 O 3 ratio of 5.7. Compared to the raw material, the parent sample prepared using Method 2 showed significant changes in its chemical composition and significant removal of exchangeable cations from the structure without...

... seawater , and iteratively solves for the latter two variables and their respective uncertainties in a Monte Carlo framework ( Thirumalai et al., 2016 ). We reconstruct seawater temperatures using the following published calibration equations, where Mg/Ca is the magnesium to calcium ratio in measured...

...Fei Qin; Ye Wu; Shengchao Xue; Dongzhou Zhang; Xiang Wu; Steven D. Jacobsen Abstract Alkali-rich aluminous high-pressure phases including calcium-ferrite (CF) type NaAlSiO 4 are thought to constitute ~20% by volume of subducted mid-ocean ridge basalt (MORB) under lower mantle conditions...

... to the residence times of boron (~10 m.y.) and calcium (~1 m.y.) within the ocean ( Broecker and Peng, 1982 ; Lemarchand et al., 2000 ), decreases in the [B(OH) 4 – ]/DIC ratio suggest a decrease in seawater borate concentrations due to a decrease in pH (which decreases the abundance of [B(OH) 4 – ] relative...

... during the interglacial stages, Holocene and interstadial events. The increased total carbonate, elemental concentrations (calcium, barium and phosphorous) and decreased magnetic susceptibility values correlate with the enhanced monsoon intensities during the above events. Glacial stages and millennial...

...Selina R. Cole; David F. Wright; Jeffrey R. Thompson Abstract Seawater magnesium (Mg) and calcium (Ca) have undergone secular fluctuations throughout the Phanerozoic, controlling whether the dominant calcium carbonate precipitant is calcite or aragonite + high-Mg calcite. Although...

... ). A calcium mineral, danburite, seems to be the most stable among other borosilicates and decomposes only at ~1000 °C with the formation of crystobalite and wollastonite, as well as gaseous B 2 O 3 ( Brun and Ghose, 1964 ). Data on the high-temperature behavior of the strontium analogue of paracelsian, i.e...