La Moinerie - Hypervelocity Impact Crater

Alternate Names Lac La Moinerie (Bottomley et al., 1990).
Coordinates 57° 25' 47" N; 66° 35' 33" W
Notes
  1. NE Quebec, 125 km SE of Kuujjuak (Ft. Chimo) on Ungava Bay.
Country Canada
Region Quebec
Date Confirmed 1978
Notes
  1. No outcrops. Impact evidence in the form of PDFs in quartz found within glacial impactite boulders on the NNE shore of the lake (Gold et al., 1978).
Buried? No
Notes
  1. Silurian fossiliferous limestone in the crater (Gold et al., 1978).
Drilled? No
Target Type Crystalline
Notes
  1. Archean quartz-feldspathic and granitic gneisses of the Nain Province (Ogilvie et al., 1984).
Sub-Type Gneiss
Apparent Crater Diameter (km) 8 km
Age (Ma) 453 ± 5
Notes :
  1. U-Pb (LA-ICP-MS) dating of apatite grains from suevites, clast-rich impact melt rocks, and polymict breccias provide a Late Ordovician age of 453 ± 5 Ma (McGregor et al., 2019). Additional age constraints: Isotopic studies of three melt samples provide an age of 400 ± 50 Ma (Bottomley et al., 1990).

Method :
  1. U-Pb
Impactor Type Unknown
Notes
  1. Melt rock samples have not been analyzed in detail for meteoritic signature elements, although preliminary analysis indicates no appreciable enrichment in Ni, Co or Cr (Ogilvie et al., 1984).

Advanced Data Fields

Notes

Local Language
N/A
Erosion
7
  1. Extensive glaciation has removed much of the original structure, including the crater-fill products and most of the central uplift (Ogilvie et al., 1978).
Final Rim Diameter
Unknown
Apparent Rim Diameter
8 km
  1. Structure is not well known. Only published data is in abstract by (Gold et al., 1978).
Rim Reliability Index
3
  1. The lake is roughly circular with a number of small central islands that are thought to be the remains of a central peak (Ogilvie et al., 1984). "~1-2 km-diameter, minor gravity high...may define the remains of a central uplift (McGregor et al., 2019).
Crater Morphology
Complex
Central Uplift Diameter
1.2? km
Central Uplift Height
Unknown
Uplift Reliability Index
Unknown
Structural Uplift
Unknown
Thickness of Seds
Unknown
Target Age
Precambrian
Marine
No
Impactor Type
Unknown
  1. Melt rock samples have not been analyzed in detail for meteoritic signature elements, although preliminary analysis indicates no appreciable enrichment in Ni, Co or Cr (Ogilvie et al., 1984).
Other Shock Metamorphism
Shock microstructures and polymorphs in apatite, titanite and zircon
  1. Zircon contains planar microstructures and shows thermal dissociation and granularization, and the first naturally occurring tetragonal zircon polymorphs. Apatite shows planar microstrucutres, vesiculation, intragrain neoblastic apatite, and neocrystalline apatite. Titanite shows planar microstructures and vesiculation (McGregor et al., 2019).
Shatter Cones
No
Planar Fractures
No
Planar Deformation Features
Yes
  1. PDFs in quartz and feldspar clasts in impact melt rock (Grieve, 2006). PDF in quartz clasts (Gold et al., 1978). "Deformation lamellae in quartz (ω, π, basal, and 25-30° c^pole) are common in some clasts and rock fragments (Gold et al., 1978).
Diaplectic Glass
No
Coesite
No
Stisovite
No
Crater Fill
LB, MB, M
  1. Breccias and melt rock collected on the down glacial part of the lake via (Robertson and Grieve, 1975) (Bottomley et al., 1990). Shock effects within suevite (McGregor et al., 2019).
Proximal Ejecta
Unknown
Distal Ejecta
Unknown
Dykes
Unknown
Volume of Melt
Unknown
Depth of Melting
Unknown

References

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R J Bottomley, D York, R A F Grieve (1978) 40Ar-39Ar dating of Canadian impact craters: Lac Couture and Lac La Moinerie, Meteoritics 13(4), p. 395, Arizona State University, Center for Meteorite Studies, Tempe, AZ, url

D P Gold, J G Tanner, D W Halliday (1978) The Lac La Moinerie Crater: A probable impact site in New Quebec, Abstracts with Programs - Geological Society of America 10(2), p. 44, Geological Society of America (GSA), Boulder, CO

R J Bottomley, D York, R A F Grieve (1990) 40Argon-39Argon dating of impact craters, Proceedings of the Lunar and Planetary Science Conference 20, Virgil L Sharpton, Graham Ryder (ed.), p. 421-431, Pergamon, New York, NY, url

M McGregor, C R M McFarlane, J G Spray (2019) Multiphase U-Pb geochronology and shock analysis of apatite, titanite and zircon from the La Moinerie impact structure, Canada, 50th Lunar and Planetary Science Conference, p. Abstract 2428, Lunar and Planetary Science Conference, Houston, TX, url

M McGregor, C R M McFarlane, J G Spray (2019) In situ multiphase U–Pb geochronology and shock analysis of apatite, titanite and zircon from the Lac La Moinerie impact structure, Canada, Contributions to Mineralogy and Petrology 174(62), p. 1-20, Springer, url, doi:10.1007/S00410-019-1598-Y