The ~227 Ma Lake St. Martin impact structure is located ~2.5 hours by road north of Winnipeg, Manitoba. The ~20 km diameter impact structure is characterized by accessible outcrops of relatively unshocked, uplifted Precambrian granites, melt rock, impact-generated gneissic rocks in the central uplift, reworked impact-produced sediments (red beds), and thick post-impact evaporate deposits of gypsum (and halite). The site serves as an analogue for understanding the formation of similar craters on Mars, such as Columbus and Endeavour, which also host post-impact evaporates. Recent investigations include characterizing the endolithic communities at this site as well as their survivability and detectability.
McCabe, H.R., and B.B. Bannatyne (1970) Lake St. Martin crypto-explosion crater and geology of the surrounding area. Geological Survey of Manitoba Geology Paper 3 (70), 1-69.
Rhind, T., J. Ronholm, B. Berg, P. Mann, D. Applin, J. Stromberg, R. Sharma, L.G. Whyte, and E.A. Cloutis (2013) Gypsum-hosted endolithic communities of the Lake St. Martin impact structure, Manitoba, Canada: spectroscopic detectability and implications for Mars. International Journal of Astrobiology, 13 (4), 366-377.
Simonds, C.H., and P.E. McGee (1979) Petrology of impactites from Lake St. Martin structure, Manitoba. Proceedings of the Lunar and Planetary Science Conference, 10,, 2493-2518.
Stromberg, J.M., D.M. Applin, E.A. Cloutis, M. Rice, G. Berard, and P. Mann (2014) The persistence of a chlorophyll spectral biosignature from Martian evaporite and spring analogues under Mars-like conditions. International Journal of Astrobiology, 13 (3), 203-223.