Advertisement

Geo-Marine Letters

, Volume 33, Issue 4, pp 245–252 | Cite as

Geological structure of Charity Shoal crater, Lake Ontario, revealed by multibeam bathymetry

  • Troy L. Holcombe
  • Scott Youngblut
  • Niall Slowey
Original

Abstract

Acoustic images of Charity Shoal in Lake Ontario, derived from a 1 × 1 m grid model of bathymetry assembled by the Canadian Hydrographic Service in 2010–2011, confirm the existence of a crater, as revealed by its surface morphology. With these higher quality data, it is possible to describe the crater in much greater detail, and arrive at a better interpretation of the geology than was possible using the earlier bathymetry of Lake Ontario. This new bathymetry of Charity Shoal reveals a continuous rim encircling an ovoid-shaped crater floor 1,200–1,500 m in diameter, with the crater floor being largely devoid of relief. Extending 3–4 km southwest of the crater is a ridge capped by a linear zone of unstratified debris that resembles a medial moraine. NE–SW erosional valleys cut across the crater rim in its southwestern sector. Apparently, glacial erosion has stripped the soil zone off stratified bedrock beneath the crater rim, exposing an intricate pattern of micro-ridges and grooves that bear the record of differential resistance to erosion of successive beds within the sequence of rock strata. Mapping of the shallow structure of the bedrock reveals a continuous ring anticline coinciding with the crater rim, with rock strata dipping gently in both directions away from the rim axis. In combination with existing evidence on the regional stratigraphy, these observations and interpretations are consistent with the Charity Shoal crater having formed in a shallow marine environment by an extraterrestrial impact event in the Middle Ordovician, followed by post-impact sedimentation, and much later, erosion during Pleistocene glaciations. Apparently, post-impact sediments infilled the crater and eventually covered the crater rim, leaving only a diminished structural expression of a crater having no more than 20 m of surface relief. Further details of crater history and origin, and a test of the hypothesis of impact, will likely come from acoustic reflection profiling and direct sampling.

Keywords

Ordovician Impact Crater Crater Floor Lake Floor Medial Moraine 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Notes

Acknowledgements

We thank the Canadian Hydrographic Service for supporting the collection of multibeam bathymetric data, C. Sadler and W. Abbott for their interest and encouragement, and L. Holcombe for assistance with illustrations. Constructive comments by A. Therriault and two anonymous reviewers proved useful in improving the manuscript.

References

  1. Brennand TA, Russell HAJ, Sharpe DR (2006) Tunnel channel character and evolution in central southern Ontario. In: Knight PG (ed) Glacier science and environmental change. Blackwell, Oxford, pp 37–39CrossRefGoogle Scholar
  2. Earth Impact Database (2012) Earth Impact Database. Planetary and Space Science Centre, University of New Brunswick, Fredericton, NB. http://www.passc.net/EarthImpactDatabase/
  3. Edsall TA, Brown CL, Kennedy GW, French JRP (1992) Surficial substrates and bathymetry of five historical lake trout spawning reefs in nearshore waters of the Great Lakes. Great Lakes Fishery Commission, Ann Arbor, MI, Tech Rep 58Google Scholar
  4. French BM, Koeberl C (2010) The convincing identification of terrestrial meteorite impact structures: what works, what doesn’t, and why. Earth Sci Rev 98:123–170CrossRefGoogle Scholar
  5. Gersonde R, Deutsch A, Ivanov BA, Kyte FT (2002) Oceanic impacts – a growing field of fundamental geoscience. Deep Sea Res II 49:951–957CrossRefGoogle Scholar
  6. Holcombe TL, Warren JS, Reid DF, Virden WT, Divins DL (2001) Small rimmed depression in Lake Ontario: an impact crater? J Great Lakes Res 27:510–517CrossRefGoogle Scholar
  7. Isachsen YW, Landing E, Lauber JM, Rickard LV, Rogers WB (eds) (2000) Geology of New York, 2nd edn. New York State Museum, NY, Educ leaflet 28Google Scholar
  8. Johnsen JH (1971) The limestones of Jefferson County. NY. New York State Museum and Science Service, Albany, Map and Chart Series 13Google Scholar
  9. Korochantseva EV, Trieloff M, Lorenz CA, Buykin AI, Ivanova MA, Schwarz WH, Hopp J, Jessberger EK (2007) L-chondrite asteroid breakup tied to Ordovician meteorite shower by multiple isochron 40Ar-39Ar dating. Meteorit Planet Sci 42:113–130CrossRefGoogle Scholar
  10. Mark K (1987) Meteorite craters. University of Arizona Press, TucsonGoogle Scholar
  11. McCall GJH (2008) Meteorite cratering: Hooke, Gilbert, Barringer, and beyond. In: McCall GJH, Bowden AJ, Howarth RJ (eds) The history of meteoritics and key meteorite collections. Geol Soc Lond Spec Publ 256:443–469Google Scholar
  12. McFall GH (1993) Structural elements and neotectonics of Prince Edward County, Southern Ontario. Geogr Quat 47:303–312Google Scholar
  13. Osinski GR (2006) The geological record of meteorite impacts. In: Proc 1st Int Conf Impact Cratering in the Solar System, 8–12 May 2006, Noordwijk, The Netherlands. Eur Space Agency Spec Publ SP-612 (CD-ROM)Google Scholar
  14. Pilkington M, Grieve RAF (1992) The geophysical signature of terrestrial impact craters. Rev Geophys 30:161–181CrossRefGoogle Scholar
  15. Puura V, Suuroja K (1992) Ordovician impact crater at Kärdla, Hiiumaa Island, Estonia. Tectonophysics 216:143–156CrossRefGoogle Scholar
  16. Roddy DJ, Boyce EM, Colton GW, Dial AL Jr (1975) Meteor crater, Arizona, rim drilling with thickness, structural uplift, diameter, depth, volume, and mass-balance calculations. In: Proc 6th Lunar Science Conf, 17–21 March 1975, Houston, TX. Pergamon Press, New York, vol 3, pp 2621–2644Google Scholar
  17. Rogers WB, Isachsen YW, Mock TD, Nyahay RE (1990) NY State geological highway map. New York State Museum, Albany, Educ leaflet 33Google Scholar
  18. Sanford BV, Baer AJ (1981) Geological map of Southern Ontario. Geological Survey of Canada, Ottawa, Map 1335AGoogle Scholar
  19. Schmitz B, Peucker-Ehrenbrink B, Lindstrom M, Tassinari M (1997) Accretion rates of meteorites and cosmic dust in the Early Ordovician. Science 278:88–90CrossRefGoogle Scholar
  20. Schmitz B, Tassinari M, Peucker-Enrenbrink B (2001) A rain of ordinary chondritic meteorites in the early Ordovician. Earth Planet Sci Lett 194:1–15CrossRefGoogle Scholar
  21. Schmitz B, Häggström T, Tassinari M (2003) Sediment-dispersed extraterrestrial chromite traces a major asteroid disruption event. Science 300:961–964CrossRefGoogle Scholar
  22. Schmitz B, Harper DAT, Peucker-Ehrenbrink B, Stouge S, Alwmark A, Cronholm A, Bergstrom SM, Tassinari M, Xiaofeng W (2008) Asteroid breakup linked to the Great Ordovician Biodiversification Event. Nat Geosci 1:49–53CrossRefGoogle Scholar
  23. Shaw J, Gilbert R (1990) Evidence for large-scale subglacial meltwater flood events in southern Ontario and northern New York State. Geology 18:1169–1172CrossRefGoogle Scholar
  24. Shoemaker EM (1960) Penetration mechanics of high-velocity meteorites illustrated by Meteor Crater, Arizona. In: Proc 21st Int Geological Congress, Copenhagen, part 8, pp 418–434Google Scholar
  25. Shoemaker EM (1987) Meteor Crater, AZ. In: Geol Soc Am Centennial Field Guide – Rocky Mountain Sect. Geological Society of America, Boulder, CO, pp 399–404Google Scholar
  26. Shoemaker EM, MacDonald FA, Shoemaker CS (2005) Geology of five small Australian impact craters. Aust J Earth Sci 52:529–544CrossRefGoogle Scholar
  27. Suuroja K, Suuroja S, All T, Floden T (2002) Kärdla (Hiiumaa Island, Estonia) – the buried and well-preserved Ordovician marine impact structure. Deep Sea Res II 49:1121–1135CrossRefGoogle Scholar
  28. Virden WT, Warren JS, Holcombe TL, Reid DF, Berggren TL (1999) Bathymetry of Lake Ontario. National Geophysical Data Center, Boulder, CO, World Data Center Mar Geol Geophys Rep MGG-14Google Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2013

Authors and Affiliations

  • Troy L. Holcombe
    • 1
  • Scott Youngblut
    • 2
  • Niall Slowey
    • 1
  1. 1.Department of OceanographyTexas A&M UniversityCollege StationUSA
  2. 2.Canadian Hydrographic ServiceFisheries and Oceans CanadaBurlingtonCanada

Personalised recommendations