Global trends in novel stable isotopes in basalts: theory and observations

Calcium Isotope Evolution During Differentiation of Vesta and Calcium Isotopic Heterogeneities in the Inner Solar System

“…However, basalts generally do not represent the Ca isotope composition of the bulk planetary body. For example, the bulk Earth δ 44/40 Ca value (∼0.94‰) is around ∼0.1‰ higher than the average N‐MORB, which is caused by low‐degree partial melting with clinopyroxene retaining a significant fraction of Ca in the residue (Eriksen & Jacobsen, 2022; Kang et al., 2017; Klaver et al., 2021; Soderman et al., 2022). Similarly, mare basalts are low‐degree partial melts of a highly heterogeneous lunar mantle, but their δ 44/40 Ca is consistent with a bulk (silicate) Moon that is isotopically heavier than lunar basalts and similar to bulk (silicate) Earth (e.g., Klaver et al., 2021; Wu et al., 2020).…”

“…The data used in this study have been deposited at https://doi.org/10.5281/zenodo.7551580. All the supporting data can be found in the cited references (Amsellem et al., 2017; Bermingham et al., 2018; Chen et al., 2020; S. Huang & Jacobsen, 2017; Kang et al., 2017; Klaver et al., 2021; Magna et al., 2015; Moynier et al., 2022; Schiller et al., 2018; Soderman et al., 2022; Valdes et al., 2014; Wu et al., 2020).…”

“…Data and sources: chondrites (Amsellem et al., 2017; S. Huang & Jacobsen, 2017; Moynier et al., 2022; Schiller et al., 2018; Valdes et al., 2014), chondrules (Amsellem et al., 2017; Bermingham et al., 2018; Schiller et al., 2018), Shergottites (Magna et al., 2015), Lunar basalts (Klaver et al., 2021; Schiller et al., 2018; Valdes et al., 2014; Wu et al., 2020), N‐MORBs (Chen et al., 2020; Soderman et al., 2022). All the data were transformed to δ 44/40 Ca values relative to NIST 915a.…”