Results 71 to 80 of about 3,762 (245)

Formation of the parent bodies of the carbonaceous chondrites [PDF]

, 1979
We have carried out extensive particle track studies for several C2 chondrites. On the basis of these and the available data on spallogenic stable and radioactive nuclides in several C1 and C2 chondrites, we have constructed a scenario for the ...
Goswami, J. N., Lal, D.
core   +1 more source

Origin and formation of a chondritic xenolith in Krymka (LL3.2, breccia): Indications for a late formation of the accretionary breccia

Meteoritics &Planetary Science, EarlyView.
Abstract An unusual chondritic xenolith was found in two sequentially prepared thin sections of a sample from the Krymka (LL3.2) chondrite. The xenolith has a rounded, slightly deformed shape of about 5 mm in apparent diameter and is partially surrounded by a double rim made of an inner fine‐grained silicate‐rich rim and an outer sulfide‐rich rim.
Aelita Girich, Addi Bischoff, Samuel Ebert, Kazuhide Nagashima, Andreas Morlok, Harald Hiesinger, Jasper Berndt   +6 more
wiley   +1 more source

Potassium isotopic compositions and exposure ages of evolved and silica‐rich achondrites

Meteoritics &Planetary Science, EarlyView.
Abstract Some of the oldest igneous rocks in the Solar System include evolved and silica‐rich achondrites that originate from parent bodies less than 1000 km in diameter, referred to as planetesimals. While Earth was initially in a molten state and required continental crust formation and plate tectonics to generate andesite bulk compositions, evolved ...
Z. Vaci, Z. Tian, P. Koefoed, M. Habermann, M. Humayun, K. Ziegler, H. Busemann, D. Krietsch, J. M. D. Day, K. Wang   +9 more
wiley   +1 more source

Organic-inorganic spatial relationships in carbonaceous chondrites [PDF]

, 2002
The use of a novel technique to determine the spatial relationships of organic and aqueously produced inorganic phases in carbonaceous chondrites, in order to support proposals of a genetic link between the ...
Sephton, M. A., Gilmour, I., Kearsley, A. T., Pearson, V. J.   +3 more
core  

Impact provenance and age of a unique basalt found in Apollo 12 regolith

Meteoritics &Planetary Science, EarlyView.
Abstract Basaltic sample 12032,366‐18 from the Apollo 12 landing site is distinct among basalts collected at this site, other Apollo landing sites, and lunar meteorites in terms of its age, bulk rock composition, and isotopic composition. We present new Pb isotopic data obtained by in situ Secondary Ion Mass Spectrometry on multiple mineral phases in ...
C. Deligny, M. J. Whitehouse, R. E. Merle, H. Jeon, A. A. Nemchin, B. L. Jolliff   +5 more
wiley   +1 more source

Poorly characterized phases in C2M carbonaceous chondrites : proposed structures and significance [PDF]

, 1984
Poorly characterized phases (PCP's) may constitute up to 30 volume percent of some C2M carbonaceous chondrite matrices [1] and are an important key to an understanding of matrix evolution. PCPs are usually fine-grained (
Zolensky, Michael E., Mackinnon, Ian D.R.   +1 more
core  

Microstructural evidence for multiple generations of sulfide precipitation and impact‐induced thermal alteration under acidic conditions on Asteroid Ryugu

Meteoritics &Planetary Science, EarlyView.
Abstract Here we report on the microstructure and chemistry of sulfide minerals returned from asteroid (162173) Ryugu. We identify a unique sulfide population in particle A0016 composed of violarite (FeNi2S4), pyrite (FeS2), chalcopyrite (CuFeS2), pyrrhotite (Fe1‐xS), and pentlandite ([Fe,Ni]9S8).
M. C. Benner, B. S. Prince, D. L. Schrader, T. J. Zega   +3 more
wiley   +1 more source

Crystallization of dmisteinbergite (hexagonal CaAl2Si2O8) from type B CAI analog melt

Meteoritics &Planetary Science, EarlyView.
Abstract Dmisteinbergite is a metastable polymorph of CaAl2Si2O8, which has been found in calcium−aluminum‐rich inclusions (CAIs) in chondrites, although anorthite is the predominant CaAl2Si2O8 phase in natural type B CAIs. The occurrence/absence of igneous dmisteinbergite would put tighter constraints on the thermal history of CAIs.
Yasuaki Tsuruoka, Hideto Yoshida, Yuki Inoue, Daiki Yamamoto, Hiroyuki Kagi, Akira Miyake, Shogo Tachibana   +6 more
wiley   +1 more source

Petrology of Amoeboid Olivine Aggregates in Antarctic CR Chondrites: Comparison With Other Carbonaceous Chondrites [PDF]

, 2016
Amoeboid olivine aggregates (AOAs) are important refractory components of carbonaceous chondrites and have been interpreted to represent solar nebular condensates that experienced high-temperature annealing, but largely escaped melting.
Komatsu, M., Fagan, T. J., Zolensky, M. E., Yamaguchi, A., Yasutake, M., Mikouchi, T.   +5 more
core   +1 more source

Amino acids in Antarctic CM1 meteorites and their relationship to other carbonaceous chondrites [PDF]

, 2007
CM2 carbonaceous chondrites are the most primitive material present in the solar system, and some of their subtypes, the CM and CI chondrites, contain up to 2 wt% of organic carbon.
Martins, Zita, Ehrenfreund, Pascale, Botta, Oliver   +2 more
core   +3 more sources