H chondrite

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H chondrite
— Group —
TypeChondrite
Structural classification?
ClassOrdinary chondrite
Subgroups
  • H3
  • H4
  • H5
Petrologic type
3 (~2.5%), 5 (40%), 4 & 6 (57.5%)
Alternative namesBronzite chondrites, Olivine bronzite chondrites

The H type ordinary chondrites are the most common type of meteorite, accounting for approximately 40% of all those catalogued, 46% of the ordinary chondrites, and 44% of all chondrites.[1] The ordinary chondrites are thought to have originated from three parent asteroids, whose fragments make up the H chondrite, L chondrite and LL chondrite groups respectively.[2]

Name

The name comes from their High iron abundance, with respect to other ordinary chondrites.

Historically, the H chondrites have been named bronzite chondrites or olivine bronzite chondrites for the dominant minerals, but these terms are now obsolete.

Parent body

A probable parent body for this group is the

near-Earth asteroids broken off from 6 Hebe
in the past, rather than originating from 6 Hebe directly.

The H chondrites have very similar trace element abundances and Oxygen isotope ratios to the IIE iron meteorites, making it likely that they both originate from the same parent body.

Iron

Their high iron abundance is about 25–31% by weight. Over half of this is present in metallic form, making these meteorites strongly magnetic despite the stony

chondritic
appearance.

Mineralogy

The most abundant minerals are

nickel-iron metal and about 5% of troilite. The majority of these meteorites have been significantly metamorphosed, with over 40% being in petrologic class
5, most of the rest in classes 4 and 6. Only a few (about 2.5%) are of the largely unaltered petrologic class 3.

Gallery

  • Gao-Guenie, H5
    Gao-Guenie, H5
  • H5 Dar Bou Nali South Morocco
    H5 Dar Bou Nali South Morocco

See also

References

  1. ^ "Natural History Museum, meteorite catalogue". Archived from the original on 2006-05-03. Retrieved 2005-11-29.
  2. ^ NASA (YouTube) – Dr. David Kring – Asteroid Initiative Workshop Cosmic Explorations Speakers Session
  3. ^ M. J. Gaffey & S. L. Gilbert Asteroid 6 Hebe: The probable parent body of the H-Type ordinary chondrites and the IIE iron meteorites, Meteoritics & Planetary Science, Vol. 33, p. 1281 (1998).

External links