{"type": "FeatureCollection", "features": [{"id": "10.1016/j.epsl.2017.04.022", "type": "Feature", "geometry": null, "properties": {"updated": "2026-05-24T16:16:07Z", "type": "Journal Article", "created": "2017-04-29", "title": "Testing the chondrule-rich accretion model for planetary embryos using calcium isotopes", "description": "Open AccessUnderstanding the composition of raw materials that formed the Earth is a crucial step towards understanding the formation of terrestrial planets and their bulk composition. Calcium is the fifth most abundant element in terrestrial planets and, therefore, is a key element with which to trace planetary composition. However, in order to use Ca isotopes as a tracer of Earth's accretion history, it is first necessary to understand the isotopic behavior of Ca during the earliest stages of planetary formation. Chondrites are some of the oldest materials of the Solar System, and the study of their isotopic composition enables understanding of how and in what conditions the Solar System formed. Here we present Ca isotope data for a suite of bulk chondrites as well as Allende (CV) chondrules. We show that most groups of carbonaceous chondrites (CV, CI, CR and CM) are significantly enriched in the lighter Ca isotopes ($\ufffd\ufffd^{44/40}Ca$ = +0.1 to +0.93 permill) compared with bulk silicate Earth ($\ufffd\ufffd^{44/40}Ca$ = +1.05 $ pm$ 0.04 permill, Huang et al., 2010) or Mars, while enstatite chondrites are indistinguishable from Earth in Ca isotope composition ($\ufffd\ufffd^{44/40}Ca$ = +0.91 to +1.06 permill). Chondrules from Allende are enriched in the heavier isotopes of Ca compared to the bulk and the matrix of the meteorite ($\ufffd\ufffd^{44/40}Ca$ = +1.00 to +1.21 permill). This implies that Earth and Mars have Ca isotope compositions that are distinct from most carbonaceous chondrites but that may be like chondrules. This Ca isotopic similarity between Earth, Mars, and chondrules is permissive of recent dynamical models of planetary formation that propose a chondrule-rich accretion model for planetary embryos.", "keywords": ["Earth and Planetary Astrophysics (astro-ph.EP)", "chondrules", "parent bodies", "calcium isotopes", "FOS: Physical sciences", "Earth", "01 natural sciences", "chondrites", "[SDU] Sciences of the Universe [physics]", "accretion", "13. Climate action", "10. No inequality", "Astrophysics - Earth and Planetary Astrophysics", "0105 earth and related environmental sciences"]}, "links": [{"href": "https://doi.org/10.1016/j.epsl.2017.04.022"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Earth%20and%20Planetary%20Science%20Letters", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1016/j.epsl.2017.04.022", "name": "item", "description": "10.1016/j.epsl.2017.04.022", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1016/j.epsl.2017.04.022"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2017-07-01T00:00:00Z"}}, {"id": "10.1016/j.gca.2016.03.006", "type": "Feature", "geometry": null, "properties": {"updated": "2026-05-24T16:16:18Z", "type": "Journal Article", "created": "2016-03-11", "title": "Cosmogenic effects on Cu isotopes in IVB iron meteorites", "description": "We measured Cu isotope compositions of 12 out of the 14 known IVB iron meteorites. Our results show that IVB iron meteorites display a very large range of \u03b465Cu values (\u22125.84\u2030\u00a0<\u00a0\u03b465Cu\u00a0<\u00a0\u22120.24\u2030; defined as per mil deviation of the 65Cu/63Cu ratio from the NIST-976 standard). These Cu isotopic data display clear correlations with W, Pt, and Os isotope ratios, which are very sensitive to secondary neutron capture due to galactic cosmic ray (GCR) irradiation. This demonstrates that \u03b465Cu in IVB irons is majorly modified by neutron capture by the reaction 62Ni(n,\u03b3)63Ni followed by beta decay to 63Cu. Using correlations with Pt and Os neutron dosimeters, we calculated a pre-exposure \u03b465Cu of \u22120.3\u00a0\u00b1\u00a00.8\u2030 (95% conf.) of IVB irons that agrees well with the Cu isotopic compositions of other iron meteorite groups and falls within the range of chondrites. This shows that the volatile depletion of the IVB parent body is not due to evaporation that should have enriched IVB irons in the heavy Cu isotopes.", "keywords": ["HF-W CHRONOMETRY", "COPPER", "01 natural sciences", "PROTRACTED CORE FORMATION", "COOLING RATES", "CHONDRITES", "[SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry", "Geochemistry and Petrology", "13. Climate action", "[SDU.STU.GC] Sciences of the Universe [physics]/Earth Sciences/Geochemistry", "RAY-PRODUCED NUCLIDES", "PARENT BODIES", "NEUTRON-CAPTURE", "HETEROGENEITY", "RAPID ACCRETION", "0105 earth and related environmental sciences"]}, "links": [{"href": "https://doi.org/10.1016/j.gca.2016.03.006"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Geochimica%20et%20Cosmochimica%20Acta", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1016/j.gca.2016.03.006", "name": "item", "description": "10.1016/j.gca.2016.03.006", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1016/j.gca.2016.03.006"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2016-06-01T00:00:00Z"}}], "links": [{"rel": "self", "type": "application/geo+json", "title": "This document as GeoJSON", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items?keywords=parent+bodies&f=json", "hreflang": "en-US"}, {"rel": "alternate", "type": "text/html", "title": "This document as HTML", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items?keywords=parent+bodies&f=html", "hreflang": "en-US"}, {"rel": "collection", "type": "application/json", "title": "Collection URL", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main", "hreflang": "en-US"}, {"type": "application/geo+json", "rel": "first", "title": "items (first)", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items?keywords=parent+bodies&", "hreflang": "en-US"}, {"rel": "last", "type": "application/geo+json", "title": "items (last)", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items?keywords=parent+bodies&offset=2", "hreflang": "en-US"}], "numberMatched": 2, "numberReturned": 2, "distributedFeatures": [], "timeStamp": "2026-05-25T02:12:57.432671Z"}