Be-B SYSTEMATICS OF HIBONITE-BEARING INCLUSIONS FROM MURCHISON
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منابع مشابه
Presolar isotopic and chemical signatures in hibonite-bearing refractory inclusions from the Murchison carbonaceous chondrite
Magnesium-, calcium-, and titanium-isotopic compositions, as well as trace-element abundances, have been determined by ion microprobe mass spectrometry for 37 hibonite-bearing inclusions from the Murchison carbonaceous chondrite. These and previously analyzed hibonite-bearing inclusions can be divided into three main groups based on morphological and mineralogical criteria. PLAty Crystal fragme...
متن کاملFIRST Ti-XANES ANALYSES OF REFRACTORY INCLUSIONS FROM MURCHISON
Introduction: A system of solar composition is so reducing that Ti and Ti can coexist, making the valence of Ti a valuable indicator of fO2 conditions during formation of nebular materials. The Ti/Ti ratios observed in the Ti-rich phases fassaite and rhönite in coarse-grained refractory inclusions from CV3 chondrites have been shown [1,2] to be quantitatively consistent with formation in a gas ...
متن کاملEvidence for distillation in the formation of HAL and related hibonite inclusions
Four hibonite-bearing refractory inclusions, HAL from Allende, DH-Hl from the Dhajala H3 chondrite, 7-404 and 7-97 1 from the Murchison CM2 chondrite, have related chemical and isotopic systematics: they exhibit large Ce and V depletions and very low Mg and Ti concentrations compared to other meteoritic hibonites and have mass-fractionated Caand Ti-isotopic compositions with emichments in the h...
متن کاملBe-B ISOTOPE SYSTEMATICS IN CV AND CM HIBONITES: IMPLICATIONS FOR SOLAR ENERGETIC PARTICLE PRODUCTION OF SHORT-LIVED NUCLIDES IN EARLY SOLAR SYSTEM
Fossil records of the now-extinct short-lived nuclide Be have been found in early solar system objects that either host other short-lived nuclides, such as, Al and Ca, or are devoid of them [1-6]. The presence of Be in several Murchison hibonites devoid of detectable radiogenic Mg (initial Al/Al <2×10) and K (initial Ca/Ca <3×10) was considered as an indicator for separate sources for these nuc...
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Introduction: Melilite-free, spinel-, hibonitebearing spherules, a major type of refractory inclusion in CM2 chondrites, consist of phases that are predicted by thermodynamic calculations to condense from a cooling gas of solar composition but are not predicted to coexist with each other. Throughout updates and additions to the data base over the years, calculations [e.g. 1-3] consistently show...
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