Maple Creek - Hypervelocity Impact Crater

Alternate Names White Valley Structure
Local Language
Coordinates 49° 47' 50" N; 109° 6' 1" W
Notes
  1. 23 km ESE of town of Maple Creek.
Country Canada
Region Saskatchewan
Date Confirmed 1998
Notes
  1. Confirmed by a few sandy lenses with PDF in quartz within the central uplift (Grieve et al., 1998).
Buried? Yes
Notes
  1. (Gent et al., 1992)
Drilled? Yes
Notes
  1. 4 shallow drill holes
Target Type Sedimentary
Notes
  1. .
Sub-Type
Apparent Crater Diameter (km) 5.75 km
Age (Ma) <72
Notes :
  1. A rough range of <72 Ma is recommended based on stratigraphic age constraints (Grieve, 2006). Previous work suggests the crater likely formed in the Late Cretaceous; the youngest units are the lowermost Eastend Formation which places the timing after 75 Ma (Grieve et al., 1998).

Method :
  1. Stratigraphy
Impactor Type Unknown

Advanced Data Fields

Notes

Erosion
6
Final Rim Diameter
Unknown
Apparent Rim Diameter
5.75 km
  1. Seismic data shows a slightly elliptical feature with a maximum diameter of 5.75 km (Gent et al., 1992). Projecting the most distal rim faults to the surface suggests a rim diameter of 7.5 km, which is also the diameter estimated from aerial photographs (Westbroek, 1997).
Rim Reliability Index
3
  1. Interpreted seismic data suggests a structural uplift of ~500 m (Grieve et al., 1998). Central area shows a discrete zone of discontinuous seismic reflections ~1.2 km in diameter (Gent et al., 1992). Central uplift diameter is ~2 km in diameter with a structural uplift of ~620 m (Westbroek, 1997).
Crater Morphology
Complex
Central Uplift Diameter
1.2km
Central Uplift Height
Unknown
Uplift Reliability Index
3
Structural Uplift
500 m
Thickness of Seds
Target Age
Mesozoic
Marine
No
Impactor Type
Other Shock Metamorphism
No
Shatter Cones
No
  1. Buried impact structure.
Planar Fractures
No
Planar Deformation Features
Yes
  1. Samples from the silty (quartz-bearing) units in industry cores of the Belly River and Lea Park formations show PDFs in rare grains of quartz (Grieve et al., 1998).
Diaplectic Glass
No
Coesite
No
Stisovite
No
Crater Fill
  1. Brecciation is reported, but no descriptions (Gent et al., 1992) (Grieve et al., 1998).
Proximal Ejecta
Distal Ejecta
Dykes
Volume of Melt
Depth of Melting

References

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M R Gent, L K Kreis, D Gendzwell (1992) The Maple creek structure, southwestern Saskatchewan, Saskatchewan Geological Survey, Sask. Energy Mines, Misc. Rep, p. 92-96

R R Stewart, D C Lawton, J H Isaac, J Tooth, W Geis (1994) The seismic expression of subsurface impact craters, Program with Abstracts - Geological Association of Canada; Mineralogical Association of Canada: Joint Annual Meeting 19, p. 107, Geological Association of Canada, Waterloo, ON, url

H Westbroek (1997) Seismic interpretation of two possible meteorite impact craters: White Valley, Saskatchewan and Purple Springs, Alberta

R A F Grieve, A M Therriault, L K Kreis (1998) Impact structures of the Western Sedimentary Basin of North America; new discoveries and hydrocarbon resources, Special Publication - Saskatchewan Geological Society 13, James E Christopher, Christopher F Gilboy, Douglas F Paterson, Stephen L Bend (ed.), p. 189-201, Saskatchewan Geological Society, Regina, SK, url

Enrico Flamini, A Coletta, M L Battagliere, M Virelli (2019) Maple Creek, Canada, Encyclopedic Atlas of Terrestrial Impact Craters, p. 551-552, Springer, Cham, url