New constraints on early Solar System chronology from Al–Mg and U–Pb isotope systematics in the unique basaltic achondrite Northwest Africa 2976

2011 ◽  
Vol 75 (18) ◽  
pp. 5310-5323 ◽  
Author(s):  
Audrey Bouvier ◽  
Lev J. Spivak-Birndorf ◽  
Gregory A. Brennecka ◽  
Meenakshi Wadhwa
Keyword(s):  
Solar System ◽  
Early Solar System ◽  
Pb Isotope ◽  
Northwest Africa ◽  
Basaltic Achondrite ◽  
Isotope Systematics

scholarly journals 26Al-26Mg isotope systematics of the first solids in the early solar system

2013 ◽  
Vol 48 (8) ◽  
pp. 1383-1400 ◽  
Author(s):  
Noriko T. Kita ◽  
Qing-Zhu Yin ◽  
Glenn J. MacPherson ◽  
Takayuki Ushikubo ◽  
Benjamin Jacobsen ◽  
...  
Keyword(s):  
Solar System ◽  
Early Solar System ◽  
Isotope Systematics

Carbonaceous achondrites Northwest Africa 6704/6693: Milestones for early Solar System chronology and genealogy

2019 ◽  
Vol 245 ◽  
pp. 577-596 ◽  
Author(s):  
Matthew E. Sanborn ◽  
Josh Wimpenny ◽  
Curtis D. Williams ◽  
Akane Yamakawa ◽  
Yuri Amelin ◽  
...  
Keyword(s):  
Solar System ◽  
Early Solar System ◽  
Northwest Africa

Insights into the chemical diversity of the martian mantle from the Pb isotope systematics of shergottite Northwest Africa 8159

2020 ◽  
Vol 545 ◽  
pp. 119638
Author(s):  
J.J. Bellucci ◽  
C.D.K. Herd ◽  
M.J. Whitehouse ◽  
A.A. Nemchin ◽  
G.G. Kenny ◽  
...  
Keyword(s):  
Chemical Diversity ◽  
Pb Isotope ◽  
Northwest Africa ◽  
Isotope Systematics

Manganese—chromium isotope systematics and the development of the early Solar System

Nature ◽  
1988 ◽  
Vol 331 (6157) ◽  
pp. 579-584 ◽  
Author(s):  
Jean-Louis Birck ◽  
Claude J. Allègre
Keyword(s):  
Solar System ◽  
Early Solar System ◽  
Isotope Systematics ◽  
Manganese Chromium

scholarly journals Crustal differentiation in the early solar system: Clues from the unique achondrite Northwest Africa 7325 (NWA 7325)

2015 ◽  
Vol 168 ◽  
pp. 280-292 ◽  
Author(s):  
J.A. Barrat ◽  
R.C. Greenwood ◽  
A.B. Verchovsky ◽  
Ph. Gillet ◽  
C. Bollinger ◽  
...  
Keyword(s):  
Solar System ◽  
Early Solar System ◽  
Northwest Africa ◽  
Crustal Differentiation

scholarly journals Olivine-rich achondrites from Vesta and the missing mantle problem

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Zoltan Vaci ◽  
James M. D. Day ◽  
Marine Paquet ◽  
Karen Ziegler ◽  
Qing-Zhu Yin ◽  
...  
Keyword(s):  
High Pressure ◽  
Solar System ◽  
Trace Element ◽  
Seismic Data ◽  
Early Solar System ◽  
Element Abundances ◽  
Northwest Africa ◽  
Remote Observation ◽  
Rich Material ◽  
Rocky Planets

AbstractMantles of rocky planets are dominantly composed of olivine and its high-pressure polymorphs, according to seismic data of Earth’s interior, the mineralogy of natural samples, and modelling results. The missing mantle problem represents the paucity of olivine-rich material among meteorite samples and remote observation of asteroids, given how common differentiated planetesimals were in the early Solar System. Here we report the discovery of new olivine-rich meteorites that have asteroidal origins and are related to V-type asteroids or vestoids. Northwest Africa 12217, 12319, and 12562 are dunites and lherzolite cumulates that have siderophile element abundances consistent with origins on highly differentiated asteroidal bodies that experienced core formation, and with trace element and oxygen and chromium isotopic compositions associated with the howardite-eucrite-diogenite meteorites. These meteorites represent a step towards the end of the shortage of olivine-rich material, allowing for full examination of differentiation processes acting on planetesimals in the earliest epoch of the Solar System.

Combined microstructural analysis and in-situ U-Pb chronology of baddeleyite within shergottites Northwest Africa (NWA) 7257, NWA 8679 and Zagami 

2021 ◽  
Author(s):  
Leanne Staddon ◽  
James Darling ◽  
Winfried Schwarz ◽  
Natasha Stephen ◽  
Sheila Schuindt ◽  
...  
Keyword(s):  
Microstructural Analysis ◽  
Shock Metamorphism ◽  
Orientation Relationships ◽  
Pb Isotope ◽  
Northwest Africa ◽  
Isotopic Analyses ◽  
Wide Range ◽  
Post Shock ◽  
Isotope Systematics

<p>Baddeleyite (monoclinic; <em>m</em>-ZrO<sub>2</sub>) is an important U-Pb chronometer within mafic lithologies from many planetary bodies. Recent <em>in-situ</em> U-Pb dating of micro-baddeleyite within shergottites has been key in confirming recent magmatic activity on Mars. However, despite a high U-Pb closure temperature (≥900 °C) and the retention of robust U-Pb isotope systematics to ~57 GPa within experimental studies, up to 80% Pb loss within baddeleyite has been reported from the highly-shocked shergottite Northwest Africa (NWA) 5298. Significantly, U-Pb isotopic disturbance has been shown to be strongly linked with baddeleyite internal microstructure, generated by partial to complete reversion from meta-stable, high P-T zirconia polymorphs during shock metamorphism. NWA 5298 has experienced elevated shock metamorphism, and particularly post-shock temperatures, in comparison to many other shergottites; in the absence of microstructural analyses, the magnitude of baddeleyite U-Pb isotopic disturbance within more moderately shocked shergottites remains unknown.</p><p>To address this, we combine electron backscatter diffraction (EBSD) microstructural analysis and in-situ U-Pb chronology of baddeleyite within three enriched shergottites: NWA 7257, NWA 8679 and Zagami. Studied samples have undergone shock conditions typical of shergottites, with complete transformation of plagioclase to maskelynite and pervasive fracturing of pyroxene, phosphates and oxides. Small veinlets of shock melt cross-cut NWA 8679 and Zagami, and shock melt pockets are present in all samples. Baddeleyite is abundant and ubiquitously associated with late-stage igneous assemblages, rather than shock melt.</p><p>We document a wide range of baddeleyite microstructures. These include crystal-plastically deformed magmatic twins, domains with a marked decrease in crystallinity, and complex, nanostructured domains with orthogonal orientation relationships that are interpreted to have resulted from complete reversion from high P-T polymorphs. Magmatic twins are only locally preserved due to shock heterogeneity. Despite this, and in contrast to NWA 5298, we find no link between baddeleyite microstructure and U-Pb isotope systematics. Analyses fall along well-defined discordia within Tera-Wasserburg plots for each sample, with the U-Pb isotopic composition of analyses controlled by overlap with surrounding phases and fractures rather than baddeleyite microstructure. We therefore determine two new, microstructurally constrained ages from discordia lower intercepts: 195 ± 15 Ma (95% confidence; MSWD 5.6) for NWA 7257 and 220 ± 23 Ma (95% confidence; MSWD 2.2) for NWA 8679. For Zagami, our findings support the previously reported magmatic crystallisation age of ~180 Ma. These results provide further confirmation that high post-shock temperatures are required to induce resolvable U-Pb isotopic disturbance baddeleyite, even within highly shocked samples, and that reversion from high P-T zirconia polymorphs alone does not necessitate U-Pb isotopic disturbance. While we caution the continued requirement for detailed microstructural analyses of baddeleyite prior to isotopic analyses, this study underlines the utility of baddeleyite chronology within martian meteorites and other shocked planetary materials.</p>

Laboratory and in-situ analysis of comet dust

1988 ◽  
Vol 46 ◽  
pp. 8-9
Author(s):  
D.E. Brownlee ◽  
A.L. Albee
Keyword(s):  
Electron Microscopy ◽  
Solar System ◽  
Laboratory Study ◽  
Isotopic Analysis ◽  
Building Blocks ◽  
Sem Analysis ◽  
Early Solar System ◽  
Cometary Material ◽  
Comet Dust

Comets are primitive, kilometer-sized bodies that formed in the outer regions of the solar system. Composed of ice and dust, comets are generally believed to be relic building blocks of the outer solar system that have been preserved at cryogenic temperatures since the formation of the Sun and planets. The analysis of cometary material is particularly important because the properties of cometary material provide direct information on the processes and environments that formed and influenced solid matter both in the early solar system and in the interstellar environments that preceded it.The first direct analyses of proven comet dust were made during the Soviet and European spacecraft encounters with Comet Halley in 1986. These missions carried time-of-flight mass spectrometers that measured mass spectra of individual micron and smaller particles. The Halley measurements were semi-quantitative but they showed that comet dust is a complex fine-grained mixture of silicates and organic material. A full understanding of comet dust will require detailed morphological, mineralogical, elemental and isotopic analysis at the finest possible scale. Electron microscopy and related microbeam techniques will play key roles in the analysis. The present and future of electron microscopy of comet samples involves laboratory study of micrometeorites collected in the stratosphere, in-situ SEM analysis of particles collected at a comet and laboratory study of samples collected from a comet and returned to the Earth for detailed study.

Preface: Evolution of the early solar system: Presolar cosmochemical fingerprints and the formation of watery rocky planets

2016 ◽  
Vol 50 (1) ◽  
pp. 1-2 ◽  
Author(s):  
Tomohiro Usui ◽  
Audrey Bouvier ◽  
Justin I. Simon ◽  
Noriko Kita
Keyword(s):  
Solar System ◽  
Early Solar System ◽  
Rocky Planets
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