|Title||Identification of the Bloody Creek structure, a possible impact crater in southwestern Nova Scotia, Canada|
|Author||Spooner, I; Stevens, G; Morrow, J; Pufahl, P; Grieve, R; Raeside, R; Pilon, J; Stanely, C; Barr, S; McMullin, D|
|Source||Meteoritics and Planetary Science vol. 44, no. 8, 2009 p. 1193-1202, https://doi.org/10.1111/j.1945-5100.2009.tb01217.x|
|Alt Series||Earth Sciences Sector, Contribution Series 200080731|
|Media||paper; on-line; digital|
|Lat/Long WENS||-65.5000 -65.0000 45.0000 44.7500|
|Subjects||extraterrestrial geology; igneous and metamorphic petrology; geophysics; craters; meteorite craters; mineralogical analyses; structural analyses; alteration; metamorphism, shock; ground probing radar;
geophysical surveys; Bloody Creek structure; Paleozoic; Devonian|
|Illustrations||location maps; photomicrographs; profiles|
|Released||2010 01 26|
|Abstract||An approximately 0.4 km diameter elliptical structure formed in Devonian granite in southwestern Nova Scotia, herein named the Bloody Creek structure (BCS), is identified as a possible impact crater.
Evidence for an impact origin is based on integrated geomorphic, geophysical, and petrographic data. A near-continuous geomorphic rim and a 10 m deep crater that is infilled with lacustrine sediments and peat define the BCS. Ground penetrating radar
shows that the crater has a depressed inner floor that is sharply ringed by a 1 m high buried scarp. Heterogeneous material under the floor, interpreted as deposits from collapse of the transient cavity walls, is overlain by stratified and faulted
lacustrine and wetland sediments.|
Alteration features found only in rim rocks include common grain comminution, polymict lithic microbreccias, kink-banded feldspar and biotite, single and multiple sets of closely spaced planar microstructures
(PMs) in quartz and feldspar, and quartz mosaicism, rare reduced mineral birefringence, and chlorite showing plastic deformation and flow microtextures. Based on their form and crystallographic orientations, the quartz PMs consist of planar
deformation features that document shock-metamorphic pressures <=25 GPa.
The age of the BCS is not determined. The low depth to diameter ratio of the crater, coupled with anomalously high shock-metamorphic pressures recorded at its exposed rim,
may be a result of significant post-impact erosion. Alternatively, impact onto glacier ice during the waning stages of Wisconsinian deglaciation (about 12 ka BP) may have resulted in dissipation of much impact energy into the ice, resulting in the
present morphology of the BCS.