manicouagan

Tvären

 Crater Name  Location  Latitude  Longitude  Diameter (km)  Age (Ma)  Exposed  Drilled  Targed Rock**  Bolid Type***
 Tvären  Sweden  N 58° 46'  E 17° 25'  2  ~ 455  N  Y  M  -

References

Abels A., Plado J., Pesonen L.J., Lehtinen M., The impact cratering record of Fennoscandia - a close look at the database, 2002.
Floden, T., Tunander, P. and Wickman,F.E., The Tvaren Bay structure, an astrobleme in southeastern Sweden. Geologiska Foreningens I Stockholm Forhandlingar, v. 108, p. 225-234. 1986.
Grahn, Y., Nolvak, J and Paris,F., Precise chitinozoan dating of Ordovician impact events in Baltoscandia, Journal of Micropalaeontology, v.15, p.21-35. 1996.
Grahn, Y., Nolvak, J., Chitinozoan dating of Ordovician impact events in Sweden and Estonia. A preliminary note. Geologiska Föreningens I Stockholm Förhandlingar, v. 115, pp. 263-264. 1993.
Henkel, H., Pesonen, L. J., Impact craters and craterform structures in Fennoscandia. Tectonophysics, v. 216, pp. 31-40. 1992.
Lindstrom M., Six Ordovician craters, 1995.
Lindström, M., Ormö, J., Sturkell, E.F.F. and Törnberg,R., Geological information from Ordovician marine impact craters (abstract). GFF, v. 118, pp. A99-A100. 1996.
Lindström, M., Flodén, T., Grahn, Y. and Kathol,B., Post-impact deposits in Tvären, a marine Middle Ordovician crater south of Stockholm, Sweden. Geological Magazine, v. 131, p. 91-103. 1994.
Lindström, M., Sturkell, E. F. F., Geology of the early Palaeozoic Lockne impact structure, central Sweden. Tectonophysics, v. 216, pp. 169-185. 1992.
Milam K.A., Deane B., Petrogenesis of central uplifts in complex terrestrial impact craters, 2005.
Milam K.A., Kuehn K., Deane B., Central uplift formation at the Middlesboro impact structure, Kentucky, USA, 2004
Nisca D.H., Elming S.A., Thunehed H., The Lycksele ring structure in northern Sweden- the result of an impact, 1996.
Ormö J., Sturkell E., Lindstrom M., Lepinette A., Resurge dynamics at the Lockne and Tvaren marine-target impact craters analysed with sedimentological and numerical methods, 2007.
Ormö J., Blomqvist, G., Magnetic modelling as a tool in the evaluation of impact structures, with special reference to the Tvären Bay impact crater, SE Sweden. Tectonophysics, v. 262, pp. 291-300. 1996.
Ormö, J., Lindstrom, M., When a cosmic impact strikes the sea bed, Geol. Mag. V.137(1), p.67-80. 2000.
Ormö, J., Blomqvist, G., Magnetic Modelling as a Tool in the Evaluation of Impact Structures, with Special Reference to the Tvaren Bay Impact Crater, SE Sweden, Tectonophysics v. 262 pp. 291-300. 1996.
Ormö, J., Blomqvist, G., Magnetic modelling as a tool in the evaluation of impact structures, with special reference to the Tvaren Bay impact crater, SE Sweden, Tectonophysics 262, 291-300. 1996.
Ormö, J., The pre-impact Ordovician stratigraphy of the Tvaren Bay impact structure, SE Sweden, GFF 116, 139-144. 1994.
Ormö, J., Törnberg, R., The Tvären Bay impact crater - pre-impact straitigraphy and shocl metamorphosis. Second International Conference. Impact Cratering and Evolution of Planet Earth. The Identification and Characterization of Impacts. 1994.
Ormö, J., The pre-impact Ordovician stratigraphy of the Tvären Bay impact structure, SE Sweden. GFF, v. 116, pp. 139-144. 1994.
Tornberg R., The resurge deposits of the marine impact structures Lockne, Tvaren and Kardla, 1999.
Törnberg, R., Impact-related resurge sedimentology as exemplified by the Lockne, Tvären and Kärdla structures (abstract). GFF, v. 118, p. A102. 1996.
Törnberg, R., Frequency distribution of shock metamorphic effects and dimensioning of the marine impact crater of the Tvären Bay, Sweden (abstract). European Science Foundation, Third International Workshop. Shock Wave Behaviour of Solids in Nature and Experiments, Limoges, France. 1994.
Wallin A., Stratigraphic importance of the Tvaren impact structure, 1999.
Wallin, Å., Hagenfeldt, S. E., Biostratigraphical investigation of Middle Ordovician acritarchs in the post-impact sequence in the Tvären-2 core, Sweden. GFF, v. 118, pp. 79-82. 1996.
Wickman, F. E., Possible impact structures in Sweden. A. Boden and K.G. Eriksson, eds., in Deep Drilling in Crystalline Bedrock, Springer-Verlag, Berlin, p. 298-327. 1988.
* pre-1977 K-Ar, Ar-Ar and Rb-Sr ages recalculated using the decay constants of Steiger and Jager (1977) Ages in millions of years (Ma) before present.

** Abbreviations: C - Crystalline Target; C-Ms - Metasedimentary Target; M - Mixed Target (i.e.sedimentary strata overlying crystalline basement); S - sedimentary target (i.e. no crystalline rocks affected by the impact event). From Osinski. G. R., Spray J. G., and Grieve R. A. F. 2007. Impact melting in sedimentary target rocks: A synthesis. In The Sedimentary Record of Meteorite Impacts, Geological Society of America Special Paper. Editors: Evans K. Horton W., King D., Morrow J., and Warme J. Geological Society of America: Boulder, in press.

***From Koeberl,C. Identification of meteoritic components in impactites. 1998, Koeberl, C. The Geochemistry and Cosmochemistry of Impacts. 2007 and PASSC Files. (IAB, IIIAB, IIIB, IIID - Iron Meteorite)