Ordinary chondritic micrometeorites from the Indian Ocean
DRS at CSIR-National Institute of Oceanography
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Title |
Ordinary chondritic micrometeorites from the Indian Ocean
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Creator |
ShyamPrasad, M.
Rudraswami, N.G. Babu, E.V.S.S.K. VijayaKumar, T. |
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Subject |
GEOLOGY AND GEOPHYSICS
GEOLOGY AND GEOPHYSICS GEOLOGY AND GEOPHYSICS |
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Description |
Extraterrestrial particulate materials on the Earth can originate in the form of collisional debris from the asteroid belt, cometary material, or as meteoroid ablation spherules. Signatures that link them to their parent bodies become obliterated if the frictional heating is severe during atmospheric entry. We investigated 481 micrometeorites isolated from ~300 kg of deep sea sediment, out of which 15 spherules appear to have retained signatures of their provenance, based on their textures, bulk chemical compositions, and relict grain compositions. Seven of these 15 spherules contain chromite grains whose compositions help in distinguishing subgroups within the ordinary chondrite sources. There are seven other spherules which comprise either entirely of dusty olivines or contain dusty olivines as relict grains. Two of these spherules appear to be chondrules from an unequilibrated ordinary chondrite. In addition, a porphyritic olivine pyroxene (POP) chondrule-like spherule is also recovered. The bulk chemical composition of all the spherules, in combination with trace elements, the chromite composition, and presence of dusty olivines suggest an ordinary chondritic source. These micrometeorites have undergone minimal frictional heating during their passage through the atmosphere and have retained these features. These micrometeorites therefore also imply there is a significant contribution from ordinary chondritic sources to the micrometeorite flux on the Earth.
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Date |
2015-08-26T04:08:12Z
2015-08-26T04:08:12Z 2015 |
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Type |
Journal Article
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Identifier |
Meteoritics & Planetary Science, vol.50(6); 2015; 1013-1031
http://drs.nio.org/drs/handle/2264/4772 |
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Language |
en
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Rights |
Copyright [2015]. All efforts have been made to respect the copyright to the best of our knowledge. Inadvertent omissions, if brought to our notice, stand for correction and withdrawal of document from this repository.
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Publisher |
The Meteoritical Society
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