Results 31 to 40 of about 6,413 (223)

Shock metamorphism of ordinary chondrites

Geochimica et Cosmochimica Acta, 1991
AbstractA revised petrographic classification of progressive stages of shock metamorphism of ordinary chondrites is proposed. Six stages of shock (S1 to S6) are defined, based on shock effects in olivine and plagioclase as recognized by thin section microscopy.
Stöffler, Dieter, Keil, Klaus, Edward R.D, Scott   +2 more
openaire   +1 more source

Re-assessing the ordinary chondrites paradox [PDF]

Astronomy and Astrophysics, 2010
Context. The so-called ordinary chondrite paradox has been a recurring topic in planetary science in the past twenty years. This paradox originated from the first comparisons between spectrophotometric measurements of meteorites and asteroids. Basically it is based on the lack of spectral analogs of the ordinay chondrites (OC) among the Main Belt ...
T. Mothé-Diniz, F. L. Jasmin, J. M. Carvano, D. Lazzaro, D. Nesvorný, A. C. Ramirez   +5 more
openaire   +1 more source

New knowledge about shock events that affected the L‐chondrite parent body from two heavily shocked L6 meteorite finds

Meteoritics &Planetary Science, EarlyView.
Abstract We report new results from a study of shock‐related features in the L6 ordinary chondrites Northwest Africa (NWA) 4672 and NWA 12841. Our observations confirm the occurrence of eight high‐pressure (HP) minerals in each meteorite, namely, ringwoodite, majorite, akimotoite, wadsleyite, albitic jadeite, lingunite, tuite, and xieite.
I. Baziotis, L. Ferrière, C. Ma, J. Hu, D. Palles, P. D. Asimow   +5 more
wiley   +1 more source

Space Weathering of Ordinary Chondrite Parent Bodies, Its Impact on the Method of Distinguishing H, L, and LL Types and Implications for Itokawa Samples Returned by the Hayabusa Mission [PDF]

, 2011
As the most abundance meteorites in our collections, ordinary chondrites potentially have very important implications on the origin and formation of our Solar System.
Hiroi, T., Noble, S. K., Pieters, C. M., Sasaki, S.   +3 more
core   +1 more source

The Origins of I-type Spherules and the Atmospheric Entry of Iron Micrometeoroids. [PDF]

, 2016
The Earth's extraterrestrial dust flux includes a wide variety of dust particles that include FeNi metallic grains. During their atmospheric entry iron micrometeoroids melt and oxidize to form cosmic spherules termed I-type spherules. These particles are
Genge, MJ
core   +1 more source

Noble gases and nitrogen in material from asteroid Bennu

Meteoritics &Planetary Science, EarlyView.
Abstract We report the elemental and isotopic abundances of all stable noble gases (helium, neon, argon, krypton, and xenon) in eight particles from asteroid Bennu returned by NASA's OSIRIS‐REx mission. We also report nitrogen abundances and isotopic ratios that were analyzed alongside neon and argon in four additional Bennu particles.
B. Marty, L. Zimmermann, E. Füri, D. V. Bekaert, J. J. Barnes, A. N. Nguyen, H. C. Connolly, D. S. Lauretta   +7 more
wiley   +1 more source

Chondrule size and related physical properties: a compilation and evaluation of current data across all meteorite groups

, 2014
The examination of the physical properties of chondrules has generally received less emphasis than other properties of meteorites such as their mineralogy, petrology, and chemical and isotopic compositions.
Biltz, Alison E., Corbett, Bernadette M., Ebel, Denton S., Friedrich, Jon M., Iotzov, Ivan V., Khan, Wajiha S., Weisberg, Michael K., Wolman, Matthew D.   +7 more
core   +1 more source

Apatite in Bennu samples indicates multiple stages of aqueous alteration

Meteoritics &Planetary Science, EarlyView.
Abstract Calcium phosphates are ubiquitous in planetary materials, including samples returned from asteroid Bennu by the OSIRIS‐REx mission. We characterized apatite [Ca5(PO4)3(F,Cl,OH)] grains in Bennu samples by scanning electron microscopy, electron microprobe analysis, and transmission electron microscopy to investigate their compositions, mineral ...
Laura B. Seifert, T. M. Erickson, L. P. Keller, J. J. Barnes, K. Thomas‐Keprta, L. Le, J. Gorce, Z. Rahman, T. J. Zega, H. C. Connolly Jr, D. S. Lauretta   +10 more
wiley   +1 more source

Surface composition and taxonomic classification of a group of near-Earth and Mars-crossing asteroids

, 2013
In the past, constraining the surface composition of near-Earth asteroids (NEAs) has been difficult due to the lack of high quality near-IR spectral data (0.7-2.5 microns) that contain mineralogically diagnostic absorption bands. Here we present visible (
Michelsen, René, Nathues, Andreas, Reddy, Vishnu, Sanchez, Juan A.   +3 more
core   +1 more source

Geochemical and petrographic re‐evaluation of ungrouped iron meteorites from Western Australia

Meteoritics &Planetary Science, EarlyView.
Abstract Under the current classification scheme, ungrouped irons make up ~11% of all recognized iron meteorites. A further ~7% of iron meteorites are currently classified as simply “irons” and are yet to be fully classified. To potentially classify these meteorites, newer approaches, including either statistical modeling or advanced geochemical ...
Ashley Rogers, Lucy Forman, Kai Rankenburg, Rachel Kirby, Martin Danišík, Victoria Cousins, Gretchen K. Benedix   +6 more
wiley   +1 more source