Corossol Impact Crater, Gulf of St Lawrence, Canada
Meteoritics
and Planetary Science, December 2013
The Corossol structure: A possible impact crater on the seafloor of the
northwestern Gulf of St. Lawrence, Eastern Canada
Patrick LAJEUNESSE, Guillaume ST-ONGE, Jacques LOCAT, Mathieu J. DUCHESNE,
Michael D. HIGGINS, Richard SANFACON and Joseph ORTIZ
We report on a 4.1 (0.2) km diameter and 185 m deep circular submarine
structure exposed on the seabed in >40 m water depths in the northwestern
Gulf of St. Lawrence (Eastern Canada) from the analysis of high-resolution
multibeam bathymetric and seismic data. The presence of a circular form
characterized by a central uplift and concentric rings resembles the
morphology and geometry of complex meteorite impact structures. Also, other
origins, such as kimberlites, intrusions, karsts, or diapirs, can be
eliminated on geological criteria. A single 4 cm long breccia fragment
recovered from the central uplift has numerous glassy droplets of
fluorapatite composition, assumed to be impact melts, and a single quartz
grain with planar intersection features thought to be shock-induced planar
deformation features (PDFs). The absolute age of this possible impact
structure is unknown, but its geological setting indicates that it was
formed long after the Mid-Ordovician and before regional pre-Quaternary
sea-level lowstands. Present results outline the need for further
examination to confirm an impact origin and to precisely date the formation
of the structure
BATHYMETRIC AND PETROLOGICAL EVIDENCE FOR A YOUNG (PLEISTOCENE?) 4-KM
DIAMETER IMPACT CRATER IN THE GULF OF SAINT LAWRENCE, CANADA.
M.
D. Higgins, P. Lajeunesse, G. St-Onge, J. Locat, M. Duchesne, J.Ortiz, R.
Sanfaçon
42nd LPSC
Houston Texas, 2011
