Neugrund crater

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Boulder of gneiss breccia on Osmussaar, Estonia, apparently thrown there by the Neugrund impact.

Neugrund is a meteorite crater in Estonia. It is 8 km (5.0 mi) in diameter and is estimated to have been formed in the Ordovician around 470 Ma. The crater is at the bottom of the sea and is not exposed at the surface. Boulders of gneissic breccia found on the coast of Osmussaar, a nearby island, are believed to have been thrown there by the explosion.[1] It has been proposed that the Neugrund crater was created during the Ordovician meteor event when a hypothetical large asteroid transferred directly into a resonant orbit with Jupiter, which shifted its orbit to intercept Earth.[2][3][4]

This attractive theory may need to be changed as more recent study puts the age of the impact in the Cambrian (485 Ma-541 Ma).[5]

References[edit]

  1. ^ "Neugrund". Earth Impact Database. University of New Brunswick. Retrieved 2009-08-19. 
  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.  Cite uses deprecated parameter |coauthors= (help)
  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. ^ Korochantseva et al. "L-chondrite asteroid breakup tied to Ordovician meteorite shower by multiple isochron 40Ar-39Ar dating" Meteoritics & Planetary Science 42, 1, pp. 3-150, Jan. 2007.
  5. ^ S. SUUROJA1, K. SUUROJA & T. FLODÉN (2013). A comparative analysis of two Early Palaeozoic marine impact structures in Estonia, Baltic Sea: Neugrund and Kärdla Bulletin of the Geological Society of Finland, Vol. 85, 2013, pp 83–101.


Coordinates: 59°20′N 23°40′E / 59.333°N 23.667°E / 59.333; 23.667