scholarly journals Discovery of fossil asteroidal ice in primitive meteorite Acfer 094

2019 ◽  
Vol 5 (11) ◽  
pp. eaax5078 ◽  
Author(s):  
Megumi Matsumoto ◽  
Akira Tsuchiyama ◽  
Aiko Nakato ◽  
Junya Matsuno ◽  
Akira Miyake ◽  
...  
Keyword(s):  
Solar Nebula ◽  
Carbonaceous Chondrite ◽  
Parent Body ◽  
Carbonaceous Chondrites ◽  
X Ray ◽  
Porous Texture ◽  
Fine Grained ◽  
X Ray Computed ◽  
Source Materials ◽  
Insight Into

Carbonaceous chondrites are meteorites believed to preserve our planet’s source materials, but the precise nature of these materials still remains uncertain. To uncover pristine planetary materials, we performed synchrotron radiation–based x-ray computed nanotomography of a primitive carbonaceous chondrite, Acfer 094, and found ultraporous lithology (UPL) widely distributed in a fine-grained matrix. UPLs are porous aggregates of amorphous and crystalline silicates, Fe─Ni sulfides, and organics. The porous texture must have been formed by removal of ice previously filling pore spaces, suggesting that UPLs represent fossils of primordial ice. The ice-bearing UPLs formed through sintering of fluffy icy dust aggregates around the H2O snow line in the solar nebula and were incorporated into the Acfer 094 parent body, providing new insight into asteroid formation by dust agglomeration.

scholarly journals Discovery of primitive CO2-bearing fluid in an aqueously altered carbonaceous chondrite

2021 ◽  
Vol 7 (17) ◽  
pp. eabg9707
Author(s):  
Akira Tsuchiyama ◽  
Akira Miyake ◽  
Satoshi Okuzumi ◽  
Akira Kitayama ◽  
Jun Kawano ◽  
...  
Keyword(s):  
Solar System ◽  
Direct Evidence ◽  
Carbonaceous Chondrite ◽  
Parent Body ◽  
Carbonaceous Chondrites ◽  
Hydrous Minerals ◽  
X Ray ◽  
Transmission Electron ◽  
X Ray Computed ◽  
Orbital Instability

Water is abundant as solid ice in the solar system and plays important roles in its evolution. Water is preserved in carbonaceous chondrites as hydroxyl and/or H2O molecules in hydrous minerals, but has not been found as liquid. To uncover such liquid, we performed synchrotron-based x-ray computed nanotomography and transmission electron microscopy with a cryo-stage of the aqueously altered carbonaceous chondrite Sutter’s Mill. We discovered CO2-bearing fluid (CO2/H2O > ~0.15) in a nanosized inclusion incorporated into a calcite crystal, appearing as CO2 ice and/or CO2 hydrate at 173 K. This is direct evidence of dynamic evolution of the solar system, requiring the Sutter’s Mill’s parent body to have formed outside the CO2 snow line and later transportation to the inner solar system because of Jupiter’s orbital instability.

scholarly journals Arrival and magnetization of carbonaceous chondrites in the asteroid belt before 4562 million years ago

2020 ◽  
Vol 1 (1) ◽  
Author(s):  
Timothy O’Brien ◽  
John A. Tarduno ◽  
Atma Anand ◽  
Aleksey V. Smirnov ◽  
Eric G. Blackman ◽  
...  
Keyword(s):  
Solar System ◽  
Arrival Time ◽  
Carbonaceous Chondrite ◽  
Parent Body ◽  
Asteroid Belt ◽  
Carbonaceous Chondrites ◽  
Early Solar System ◽  
Outer Disk ◽  
Main Asteroid Belt ◽  
Insight Into

AbstractMeteorite magnetizations can provide rare insight into early Solar System evolution. Such data take on new importance with recognition of the isotopic dichotomy between non-carbonaceous and carbonaceous meteorites, representing distinct inner and outer disk reservoirs, and the likelihood that parent body asteroids were once separated by Jupiter and subsequently mixed. The arrival time of these parent bodies into the main asteroid belt, however, has heretofore been unknown. Herein, we show that weak CV (Vigarano type) and CM (Mighei type) carbonaceous chondrite remanent magnetizations indicate acquisition by the solar wind 4.2 to 4.8 million years after Ca-Al-rich inclusion (CAI) formation at heliocentric distances of ~2–4 AU. These data thus indicate that the CV and CM parent asteroids had arrived near, or within, the orbital range of the present-day asteroid belt from the outer disk isotopic reservoir within the first 5 million years of Solar System history.

scholarly journals 8. Genetic Relations among Meteorites and Planets

1977 ◽  
Vol 39 ◽  
pp. 545-550 ◽  
Author(s):  
R. N. Clayton
Keyword(s):  
Solar Nebula ◽  
Major Element ◽  
Carbonaceous Chondrite ◽  
Carbonaceous Chondrites ◽  
Powerful Method ◽  
Ordinary Chondrites ◽  
Element Abundances ◽  
The Earth ◽  
Enstatite Chondrites ◽  
Source Materials

On the basis of 180/160 and 170/160 ratios, meteorites and planets can be grouped into at least nine categories, as follows (in order of increasing 1°0): (1) type L and LL ordinary chondrites; (2) type H ordinary chondrites, type HE irons, and CI carbonaceous chondrites; (3) the nakhlites and Shergotty; (4) the earth, moon, and enstatite chondrites and achondrites; (5) basaltic achondrites, hypersthene achondrites, mesosiderites, pallasites and type IRB irons; (6) the ureilites; (7) C2 carbonaceous chondrite matrix, Bencubbin, Weatherford, and Kakangari; (8) C3 carbonaceous chondrites; (9) pallasites Eagle Station and Itzawisis. Objects of one category cannot be derived by fractionation or differentiation from the source materials of any other category, but must represent samples of different regions of an i nhomogeneous solar nebula. The isotopic classification, together with major-element abundances, provides a powerful method for recognition of interrelationships of the various meteorites and their parent bodies.

Machiite, Al2Ti3O9, a new oxide mineral from the Murchison carbonaceous chondrite: A new ultra-refractory phase from the solar nebula

2020 ◽  
Vol 105 (2) ◽  
pp. 239-243 ◽  
Author(s):  
Alexander N. Krot ◽  
Kazuhide Nagashima ◽  
George R. Rossman
Keyword(s):  
Isotopic Composition ◽  
Solar Nebula ◽  
Carbonaceous Chondrite ◽  
Parent Body ◽  
Oxygen Isotopic Composition ◽  
New Mineral ◽  
Calculated Density ◽  
California Institute Of Technology ◽  
Oxygen Isotopic ◽  
Institute Of Technology

Abstract Machiite (IMA 2016-067), Al2Ti3O9, is a new mineral that occurs as a single euhedral crystal, 4.4 μm in size, in contact with an euhedral corundum grain, 12 μm in size, in a matrix of the Murchison CM2 carbonaceous chondrite. The mean chemical composition of holotype machiite by electron probe microanalysis is (wt%) TiO2 59.75, Al2O3 15.97, Sc2O3 10.29, ZrO2 9.18, Y2O3 2.86, FeO 1.09, CaO 0.44, SiO2 0.20, MgO 0.10, total 99.87, giving rise to an empirical formula (based on 9 oxygen atoms pfu) of (Al1.17Sc0.56Y0.10Ti0.084+Fe0.06Ca0.03Mg0.01)(Ti2.714+Zr0.28Si0.01)O9. The general formula is (Al,Sc)2(Ti4+,Zr)3O9. The end-member formula is Al2Ti3O9. Machiite has the C2/c schreyerite-type structure with a = 17.10 Å, b = 5.03 Å, c = 7.06 Å, β = 107°, V = 581 Å3, and Z = 4, as revealed by electron backscatter diffraction. The calculated density using the measured composition is 4.27 g/cm3. The machiite crystal is highly 16O-depleted relative to the coexisting corundum grain (Δ17O = –0.2 ± 2.4‰ and –24.1 ± 2.6‰, respectively; where Δ17O = δ17O – 0.52 × δ18O). Machiite is a new member of the schreyerite (V2Ti3O9) group and a new Sc,Zr-rich ultrarefractory phase formed in the solar nebula, either by gas-solid condensation or as a result of crystallization from a Ca,Al-rich melt having solar-like oxygen isotopic composition (Δ17O~ –25‰) under high-temperature (~1400–1500 °C) and low-pressure (~10-4–10-5 bar) conditions in the CAI-forming region near the protosun. The currently observed disequilibrium oxygen isotopic composition between machiite and corundum may indicate that machiite subsequently experienced oxygen isotopic exchange with a planetary-like 16O-poor gaseous reservoir either in the solar nebula or on the CM chondrite parent body. The name machiite is in honor of Chi Ma, mineralogist at California Institute of Technology, for his contributions to meteorite mineralogy and discovery of many new minerals representing extreme conditions of formation.

scholarly journals Tungsten isotopic constraints on the age and origin of chondrules

2016 ◽  
Vol 113 (11) ◽  
pp. 2886-2891 ◽  
Author(s):  
Gerrit Budde ◽  
Thorsten Kleine ◽  
Thomas S. Kruijer ◽  
Christoph Burkhardt ◽  
Knut Metzler
Keyword(s):  
Planet Formation ◽  
Solar Nebula ◽  
Carbonaceous Chondrite ◽  
Critical Role ◽  
Parent Body ◽  
Uneven Distribution ◽  
Time Interval ◽  
Ordinary Chondrites ◽  
Chondrule Formation ◽  
Isotopic Constraints

Chondrules may have played a critical role in the earliest stages of planet formation by mediating the accumulation of dust into planetesimals. However, the origin of chondrules and their significance for planetesimal accretion remain enigmatic. Here, we show that chondrules and matrix in the carbonaceous chondrite Allende have complementary 183W anomalies resulting from the uneven distribution of presolar, stellar-derived dust. These data refute an origin of chondrules in protoplanetary collisions and, instead, indicate that chondrules and matrix formed together from a common reservoir of solar nebula dust. Because bulk Allende exhibits no 183W anomaly, chondrules and matrix must have accreted rapidly to their parent body, implying that the majority of chondrules from a given chondrite group formed in a narrow time interval. Based on Hf-W chronometry on Allende chondrules and matrix, this event occurred ∼2 million years after formation of the first solids, about coeval to chondrule formation in ordinary chondrites.

Specimen nonuniformities in water-pluviated and moist-tamped sands under undrained triaxial compression and extension

2008 ◽  
Vol 45 (7) ◽  
pp. 939-956 ◽  
Author(s):  
P. R. Thomson ◽  
R. C.K. Wong
Keyword(s):  
Computed Tomography ◽  
Axial Load ◽  
Void Ratio ◽  
Triaxial Compression ◽  
Stress Path ◽  
Saturated Sand ◽  
Ratio Distribution ◽  
X Ray ◽  
X Ray Computed ◽  
Insight Into

X-ray computed tomography (CT) methods and specialized triaxial equipment were developed to quantify void ratio distribution within saturated sand specimens reconstituted by water pluviation and moist tamping methods during undrained triaxial compression and extension. The CT measurements were obtained at several points along the stress path of each specimen without significant removal of axial load. It was observed that two reconstitution methods yielded very different void ratio distributions within specimens. Significant void ratio redistribution occurred within each specimen during the undrained shearing tests. The influences of void ratio redistribution on globally observed specimen responses are discussed. The findings of this research investigation provide unique insight into fundamental aspects of saturated sand behaviour during undrained triaxial shearing.

Bright carbonate veins on asteroid (101955) Bennu: Implications for aqueous alteration history

Science ◽  
2020 ◽  
Vol 370 (6517) ◽  
pp. eabc3557 ◽  
Author(s):  
H. H. Kaplan ◽  
D. S. Lauretta ◽  
A. A. Simon ◽  
V. E. Hamilton ◽  
D. N. DellaGiustina ◽  
...  
Keyword(s):  
Fluid Flow ◽  
Solar System ◽  
Hydrothermal Alteration ◽  
Large Scale ◽  
Carbonaceous Chondrite ◽  
Parent Body ◽  
Early Solar System ◽  
Aqueous Alteration ◽  
Insight Into ◽  
Geologic Processes

The composition of asteroids and their connection to meteorites provide insight into geologic processes that occurred in the early Solar System. We present spectra of the Nightingale crater region on near-Earth asteroid Bennu with a distinct infrared absorption around 3.4 micrometers. Corresponding images of boulders show centimeters-thick, roughly meter-long bright veins. We interpret the veins as being composed of carbonates, similar to those found in aqueously altered carbonaceous chondrite meteorites. If the veins on Bennu are carbonates, fluid flow and hydrothermal deposition on Bennu’s parent body would have occurred on kilometer scales for thousands to millions of years. This suggests large-scale, open-system hydrothermal alteration of carbonaceous asteroids in the early Solar System.

Carbonaceous chondrite meteorites as a record of protoplanetary disk conditions

2019 ◽  
Vol 15 (S350) ◽  
pp. 135-138
Author(s):  
Sara S. Russell ◽  
Enrica Bonato ◽  
Helena Bates ◽  
Ashley J. King ◽  
Natasha V. Almeida ◽  
...  
Keyword(s):  
Organic Molecules ◽  
Carbonaceous Chondrite ◽  
Protoplanetary Disk ◽  
Parent Body ◽  
Carbonaceous Chondrites ◽  
Aqueous Processing ◽  
Chondritic Meteorites ◽  
Dust Component ◽  
Key Features ◽  
Complex Organic

AbstractChondritic meteorites, and especially the most volatile-rich chondrites, the carbonaceous chondrites, preserve a record of the solar protoplanetary disk dust component and how it has been changed both in the disk environment itself and in its asteroidal parent body. Here we review some of the key features of carbonaceous chondrites and report some new data on their organics component. These show that the nebula reached temperature of >10000C, but only very locally, to produce chondrules. Most meteoritic material underwent thermal and/or aqueous processing, but some retain delicate nebular components such as complex organic molecules and amorphous silicates.

scholarly journals Fine-grained dust rims in the Tagish Lake carbonaceous chondrite: Evidence for parent body alteration

2005 ◽  
Vol 40 (9-10) ◽  
pp. 1413-1431 ◽  
Author(s):  
Ansgar Greshake ◽  
Alexander N. Krot ◽  
George J. Flynn ◽  
Klaus Keil
Keyword(s):  
Carbonaceous Chondrite ◽  
Parent Body ◽  
Fine Grained
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