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Glasford

 Crater Name  Location  Latitude  Longitude  Diameter (km)  Age (Ma)  Exposed  Drilled  Target Rock**  Bolide Type***
 Glasford  Illinois, U.S.A.  N 40° 36'  W 89° 47'  4  < 430  N  Y  S  -

References

Buschbach, T. C., Ryan, R., Ordovician explosion structure at Glasford, Illinois. Bulletin of the American Association of Petroleum Geologists, v. 47, pp. 2015-2022. 1963.
Dietz, R. S., McHone, J. F., Astroblemes recently confirmed with shatter cones (abstract). Meteoritics, v. 26, p. 332. 1991.
McHone, J. F., Sargent, M.L. and Nelson,W.J., Shatter cones in Illinois: Evidence for meteoritic impacts at Glasford and Des Plaines (abstract). Meteoritics, v. 21, p. 446. 1986.
Snyder, F. G., Gerdemann, P. E., Explosive igneous activity along an Illinois-Missouri-Kansas axis. American Journal of Science, v. 263, pp. 465-493. 1965.
* 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)