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A global rain of micrometeorites following breakup of the L-chondrite parent body-Evidence from solar wind-implanted Ne in fossil extraterrestrial chromite grains from China

Alwmark, Carl LU ; Schmitz, Birger LU ; Meier, Matthias LU ; Baur, H. and Wieler, R. (2012) In Meteoritics and Planetary Science 47(8). p.1297-1304
Abstract
Previous studies of limestone beds of mid-Ordovician age from both Sweden and China show that the Earth saw an at least two orders of magnitude increase in the influx of extraterrestrial material approximately 470 Ma, following the disruption of an L-chondrite parent body in the asteroid belt. Recovered extraterrestrial material consists of fossil meteorites and sediment-dispersed extraterrestrial chromite (SEC) grains, both with L-chondritic origin. Ne isotope analysis of SEC grains from one of the Swedish limestone sections revealed that the vast majority of the grains were delivered to Earth as micrometeorites. In this study, we extend the previous work, both in time and geographically, by measuring concentrations and isotopic ratios of... (More)
Previous studies of limestone beds of mid-Ordovician age from both Sweden and China show that the Earth saw an at least two orders of magnitude increase in the influx of extraterrestrial material approximately 470 Ma, following the disruption of an L-chondrite parent body in the asteroid belt. Recovered extraterrestrial material consists of fossil meteorites and sediment-dispersed extraterrestrial chromite (SEC) grains, both with L-chondritic origin. Ne isotope analysis of SEC grains from one of the Swedish limestone sections revealed that the vast majority of the grains were delivered to Earth as micrometeorites. In this study, we extend the previous work, both in time and geographically, by measuring concentrations and isotopic ratios of Ne in individual SEC grains (60120 mu m in diameter) from three different beds from a contemporary Middle Ordovician limestone section in China. All of the Chinese SEC grains, 44 in total, contain surface-implanted Ne of fractionated solar wind composition, implying that these grains were, as in the case of the Swedish SEC grains, delivered to Earth as micrometeorites. This gives further compelling evidence that the two to three orders of magnitude increase in the influx of micrometeoritic material following the breakup of the L-chondrite parent body was indeed a global event. The rain of micrometeorites prevailed for at least 2 Myr (the estimated time of the deposition of the topmost Chinese bed) after the breakup event. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Meteoritics and Planetary Science
volume
47
issue
8
pages
1297 - 1304
publisher
Wiley-Blackwell
external identifiers
  • wos:000307723400005
  • scopus:84865279552
ISSN
1086-9379
DOI
10.1111/j.1945-5100.2012.01394.x
language
English
LU publication?
yes
id
96456be2-6354-4d28-a5ef-f584b48d462e (old id 3151986)
date added to LUP
2012-10-29 11:01:19
date last changed
2017-08-20 04:11:49
@article{96456be2-6354-4d28-a5ef-f584b48d462e,
  abstract     = {Previous studies of limestone beds of mid-Ordovician age from both Sweden and China show that the Earth saw an at least two orders of magnitude increase in the influx of extraterrestrial material approximately 470 Ma, following the disruption of an L-chondrite parent body in the asteroid belt. Recovered extraterrestrial material consists of fossil meteorites and sediment-dispersed extraterrestrial chromite (SEC) grains, both with L-chondritic origin. Ne isotope analysis of SEC grains from one of the Swedish limestone sections revealed that the vast majority of the grains were delivered to Earth as micrometeorites. In this study, we extend the previous work, both in time and geographically, by measuring concentrations and isotopic ratios of Ne in individual SEC grains (60120 mu m in diameter) from three different beds from a contemporary Middle Ordovician limestone section in China. All of the Chinese SEC grains, 44 in total, contain surface-implanted Ne of fractionated solar wind composition, implying that these grains were, as in the case of the Swedish SEC grains, delivered to Earth as micrometeorites. This gives further compelling evidence that the two to three orders of magnitude increase in the influx of micrometeoritic material following the breakup of the L-chondrite parent body was indeed a global event. The rain of micrometeorites prevailed for at least 2 Myr (the estimated time of the deposition of the topmost Chinese bed) after the breakup event.},
  author       = {Alwmark, Carl and Schmitz, Birger and Meier, Matthias and Baur, H. and Wieler, R.},
  issn         = {1086-9379},
  language     = {eng},
  number       = {8},
  pages        = {1297--1304},
  publisher    = {Wiley-Blackwell},
  series       = {Meteoritics and Planetary Science},
  title        = {A global rain of micrometeorites following breakup of the L-chondrite parent body-Evidence from solar wind-implanted Ne in fossil extraterrestrial chromite grains from China},
  url          = {http://dx.doi.org/10.1111/j.1945-5100.2012.01394.x},
  volume       = {47},
  year         = {2012},
}