Ordovician meteor event
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.[2][3][1] 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.[4][1]
References
- ^ 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. Retrieved 23 September 2016.
- ^ Heck, Philipp (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.
{{cite journal}}: Unknown parameter|coauthors=ignored (|author=suggested) (help) - ^ 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).
- ^ 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.
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