Ordovician meteor event

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Paleogeography of the Middle Ordovician (~470 Ma)

The Ordovician meteor event was a dramatic increase in the rate at which L chondrite meteorites fell to Earth during the Middle Ordovician period, 467.3 ± 1.6 million years ago.[1] This is indicated by the comparatively tight age clustering of L chondrite grains in sediments in southern Sweden, and an excess of fossil L chondrite meteorites in a quarry in Sweden that represents meteorite falls arriving at a much higher rate than is typical on Earth.[1][2][3] This temporary increase in the impact rate was most likely caused by the destruction of the L-chondrite parent body 470 ± 6 million years ago having scattered fragments into Earth-crossing orbits, a chronology which is supported by shock ages in numerous L-chondrite meteorites that continue to fall to Earth today.[4] It is hypothesized that this influx was associated with, or possibly caused, the Great Ordovician Biodiversification Event.[1][4]

Possible craters[edit]

Ordovician meteor event is located in Earth
Ordovician meteor event
Ordovician meteor event
Ordovician meteor event
Ordovician meteor event
Ordovician meteor event
Ordovician meteor event
Ordovician meteor event
Locations of possible craters related to the event

Formerly estimated to be Ordovician, revised to Cambrian (~535 Ma)
Turquoise pog.svg Neugrund crater

See also[edit]

References[edit]

  1. ^ a b c Korochantseva, Ekaterina; Trieloff, Mario; Lorenz, Cyrill; Buykin, Alexey; Ivanova, Marina; Schwarz, Winfried; Hopp, Jens; Jessberger, Elmar (2007). "L-chondrite asteroid breakup tied to Ordovician meteorite shower by multiple isochron 40 Ar- 39 Ar dating". Meteoritics & Planetary Science. 42 (1): 113–130. doi:10.1111/j.1945-5100.2007.tb00221.x. Retrieved 23 September 2016. 
  2. ^ Heck, Philipp; Birger Schmitz; Heinrich Baur; Alex N. Halliday; Rainer Wieler (15 July 2004). "Fast delivery of meteorites to Earth after a major asteroid collision". Nature. 430 (6997): 323–325. Bibcode:2004Natur.430..323H. doi:10.1038/nature02736. PMID 15254530. 
  3. ^ H. Haack et al. Meteorite, asteroidal, and theoretical constraints on the 500-Ma disruption of the L chondrite parent body, Icarus, Vol. 119, p. 182 (1996).
  4. ^ a b Schmitz, Birger; Harper, David; et. al. (16 December 2007). "Asteroid breakup linked to the Great Ordovician Biodiversification Event". Nature Geoscience: 49–53. doi:10.1038/ngeo.2007.37.