West Hawk - Hypervelocity Impact Crater

Alternate Names West Hawk Lake (Dence et al., 1968).
Local Language
Coordinates 49° 46' 1" N; 95° 10' 60" W
Notes
  1. SE Manitoba, just W of the Ontario border. The lake lies within Whiteshell Provincial Park and is about 100 km E of Winnipeg.
Country Canada
Region Manitoba
Date Confirmed 1966
Notes
  1. Evidence from drill cores showing brecciation, quartz with PDFs (Halliday and Griffin, 1966). A meteoric origin suggested due to the lake geometry and a gravity anomaly (Halliday and Griffin, 1963).
Buried? Yes
Notes
  1. Because of extensive erosion of the rim, the lake has covered the original impact site (Ogilvie et al., 1984).
Drilled? Yes
Notes
  1. 4 bore holes were drilled into West Hawk Lake, 65-1 is closest to the crater centre; holes 66-3, 66-2 and 66-1 are 260, 305 and 1159 m the SW, respectively (Halliday and Griffin, 1967).
Target Type Crystalline
Notes
  1. The southern boundary of the lake is underlain by volcanic greenstones of Archean age while the northern area consists of Keewatin metaclastic sediments and tuffs underlain by granite and gneiss (Halliday and Griffin, 1963).
Sub-Type Gneiss, Greenstone, Volcanics, Granite
Apparent Crater Diameter (km) 3.6 km
Age (Ma) 351 ± 20
Notes :
  1. 351 ± 20 Ma determined by fission track (Grieve, 2006). A rough Mesozoic age is calculated from the study of the lake sediments (Oglivie et al., 1984).

Method :
  1. Fission track
Impactor Type Unknown

Advanced Data Fields

Notes

Erosion
4
  1. The present shoreline, with an average diameter of 3.6 km, has been derived from the original crater by severe erosion of the fractured rim. The present erosion plane is approximately 66 m below the original surface (Halliday and Griffin, 1967).
Final Rim Diameter
Unknown
Apparent Rim Diameter
3.6 km
  1. Lies entirely within a lake. Some debate over original dimensions; see (Halliday and Griffin, 1967) (Short, 1970) and (Grieve et al., 1989).
Rim Reliability Index
3
  1. The nearly circular structure filled with consolidated sediments underlain by a breccia lens and fractured bedrock. The initial crater is now completely submerged by the present lake (Short, 1970).
Crater Morphology
Simple
Central Uplift Diameter
km
Central Uplift Height
Unknown
Uplift Reliability Index
Structural Uplift
Unknown
Thickness of Seds
Target Age
Precambrian
Marine
No
Impactor Type
Other Shock Metamorphism
No
Shatter Cones
No
  1. Lake - buried impact structure.
Planar Fractures
Yes
  1. Fig. 4 (Robertson et al., 1968) shows two sets of cleavage fractures {1011} plus a weaker set {5161}. Fig. 6 (Halliday and Griffin, 1966) shows cleavage fractures of quartz from 1488 ft depth.
Planar Deformation Features
Yes
  1. PDF in quartz grains (Halliday and Griffin, 1966) (Short, 1967). PDF in quartz (Short, 1970). **see (Short, 1970 uses term planar "feature", not PDF, see also for details on orientation). 235 sets of planar features from 81 quartz grains confirmed Types A, B, C, D deformation (Robertson et al., 1968).
Diaplectic Glass
No
Coesite
No
Stisovite
No
Crater Fill
LB, MB
  1. (Short, 1970) describes three types of LB from a drill core at the center of the structure: (1) a LB with a dark-brown particulate matrix derived largely by grinding up the outer parts of the fragments, which did not move relative to each other and were not mixed with particles of either immediately adjacent layers or from other units (parauthocthonous basement rocks?); (2) a monomict LB (crater-fill) with larger proportions of matrix (up to 50%) overlying the the first LB described; and (3) a polymict LB. Melt-bearing breccias (referred to as suevites) are also reported within the polymict LB, but the glass clasts are not described. Autobrecciation, cataclastic fragmentation, and injection of shocked breccia into open fractures account for observed effects in the rupture zone (Short, 1970). Quartz-feldspar-biotite schists undergo varying degrees of alteration to thetomorphs or to melt-quenched glass (Short, 1970). Suevite in polymict breccia (Short, 1970).
Proximal Ejecta
Distal Ejecta
Dykes
Volume of Melt
Depth of Melting

References

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I Halliday, A A Griffin (1963) Evidence in support of a meteoritic origin for West Hawk Lake, Manitoba, Canada, Journal of Geophysical Research 68(18), p. 5297-5305, American Geophysical Union, Washington, DC, url

I Halliday, A A Griffin (1963) R.A.S.C. papers - West Hawk Lake-Manitoba's ancient crater and modern resort, Journal of the Royal Astronomical Society of Canada 57, p. 24, url

I Halliday, A A Griffin (1964) Application of the scientific method to problems of crater recognition, Meteoritics 2(2), p. 79-84, Arizona State University, Center for Meteorite Studies, Tempe, AZ, url

I Halliday, A A Griffin (1966) Preliminary results from drilling at the West Hawk Lake crater, Journal of the Royal Astronomical Society of Canada 60(2), p. 59-68, Royal Astronomical Society of Canada, Toronto, url

N M Short (1967) Petrographic evidence for an impact origin for the West Hawk Lake structure, Manitoba, Canada, Transactions - American Geophysical Union 48(1), p. 147, American Geophysical Union, Washington, DC, url

I Halliday, A A Griffin (1967) Summary of drilling at the West Hawk Lake crater, Journal of the Royal Astronomical Society of Canada 61(1), p. 108, Royal Astronomical Society of Canada, Toronto, url

C S Beals (1967) Terrestrial meteorite craters and their lunar counterparts, Ottawa Dominion Observatory Contributions 7, p. 1-10

M R Dence, M J S Innes, P B Robertson (1968) Recent geological and geophysical studies of Canadian craters, Contributions from the Dominion Astrophysical Observatory in Victoria 8, url

P B Robertson, M R Dence, M A Vos (1968) Deformation in rock-forming minerals from Canadian craters., Contributions from the Dominion Astrophysical Observatory in Victoria 8(23), p. 20, url

J F Clark (1969) Magnetic surveys at West Hawk lake, Manitoba, Canada, Meteoritics 4(4), p. 268, Arizona State University, Center for Meteorite Studies, Tempe, AZ, url

N M Short (1970) Anatomy of a meteorite impact crater; West Hawk Lake, Manitoba, Canada, Geological Society of America Bulletin 81(3), p. 609-648, Geological Society of America (GSA), Boulder, CO, url, doi:http://dx.doi.org/10.1130/0016-7606(1970)81[609:AOAMIC]2.0.CO;2

N M Short (1970) Anatomy of a meteorite impact crater: West Hawk Lake, Manitoba, Canada, Geological Society of America Bulletin 81(March), p. 609-648

M R Dence (1972) The nature and significance of terrestrial impact structures, International Geological Congress, 24th, p. 77-89, url

R B Robertson, R A F Grieve (1975) Impact structures in Canada: Their recognition and characteristics, Journal of the Royal Astronomical Society of Canada 69, p. 1-21, url

A I Dabizha, M S Krass (1975) The evolution of explosive meteorite craters on Earth (in Russian), Zemlya i Vselennaya 5, p. 80-88

A I Dabizha, M S Krass, V V Fedynsky (1975) Evolution of meteorite craters as structures of planetary crust (in Russian), Astronomicheskii Vestnik 10, p. 5-18

A I Dabizha, V V Fedynsky (1977) Features of the gravitational field of astroblemes (in Russian), Meteoritika 36, p. 113-120

C A Holman () Geochemistry and petrology of Archean greenstones of the West Hawk Lake-Falcon Lake Area, eastern Manitoba, Geochemistry and petrology of Archean greenstones of the West Hawk Lake-Falcon Lake Area, eastern Manitoba, p. 47

J F Clark (1980) Geomagnetic surveys at West Hawk Lake, Manitoba, Canada, Geomagnetic Series (Ottawa) = Serie Geomagnetique (Ottawa)(20), p. 11, Energy, Mines and Resources Canada, Earth Physics Branch, Ottawa, ON, url

R G Scott, M Pilkington, E I Tanczyk, R A F Grieve (1995) Magnetic properties of three impact structures in Canada, Meteoritics 30, p. 576-577, url

R G Scott, M Pilkington, E I Tanczyk (1997) Magnetic investigations of the West Hawk, Deep Bay and Clearwater impact structures, Canada, Meteoritics & Planetary Science 32(2), p. 293-308, Meteoritical Society, Fayetteville, AR, url, doi:http://dx.doi.org/10.1111/j.1945-5100.1997.tb01267.x

L D Stasiuk, G D Lockhart, W W Nassichuk, J A Carlson (1999) Thermal maturity evaluation of dispersed organic matter inclusions from kimberlite pipes, Lac de Gras, Northwest Territories, Canada, International Journal of Coal Geology 40(1), p. 1-25, Elsevier, Amsterdam, url

K G Osadetz, B P Kohn, S Feinstein, P B O'Sullivan (2002) Thermal history of Canadian Williston basin from apatite fission-track thermochronology—implications for petroleum systems and geodynamic history, Tectonophysics 349(1-4), p. 221-249, url, doi:10.1016/S0040-1951(02)00055-0

M Boyd, H J Kling, D Schnurrenberger, J T Teller (2002) Coring of West Hawk Lake meteorite impact crater; deep-water technique and initial results, Program and Abstracts of the ... Conference of the International Association for Great Lakes Research 45, p. 14, International Association for Great Lakes Research (IAGLR), [location varies]

J T Teller, Z Yang, M Boyd, W M Buhay, K McMillan, H J Kling, A M Telka (2008) Postglacial sedimentary record and history of West Hawk Lake crater, Manitoba, Journal of Paleolimnology 40(2), p. 661-688, Springer, Dordrecht, url, doi:http://dx.doi.org/10.1007/s10933-008-9192-8