Characteristics and Formation of Central Uplifts in Crystalling Terrestrial Impact Craters: Comprehensive Proposal
It is now widely recognized that impact cratering is a ubiquitous geological process that affects all planetary objects with a solid surface and can produce shock metamorphic features, impact melt rocks and a variety of impact melt-bearing and melt-free breccias. When the size of an impact crater is above a certain size threshold, the transient cavity is unstable and undergoes modification by gravitational forces, producing a complex impact crater. Uplift of the transient crater floor occurs leading to the development of a central uplift (e.g., Melosh and Ivanov 1999).
The formation of central uplifts remains one of the least well-understood aspects of the impact cratering process. One main goal of this project is to further our understanding of the mechanics of central uplift formation in complex impact craters. The specific objectives are to: understand the weakening mechanisms responsible for central uplift formation, explore the role melt-bearing dykes might play in the formation of central uplifts, and to understand the effects of target lithology on central uplift formation. This will be achieved by carrying out a comparative study of two mid-size complex impact craters: the Mistastin Lake impact structure and the Slate Islands impact structure.
A. C. Singleton, G. Osinski, C. Samson, S. Holladay, M-C. Williamson. (2010). Electromagnetic characterization of polar ice wedge polygons: implications for periglacial studies on Mars. Planetary and Space Science 58: 472–481.
A. C. Singleton, G. Osinski, P.J.A. McCausland, and D.E. Moser. Shock induced changes in density and porosity in shock metamorphosed crystalline rocks, Haughton impact structure, Canada. Meteoritics and Planetary Science (in press).
Conference Presentations & Abstracts
A. C. Singleton, G. R. Osinski, R. A. F. Grieve, C. Shaver. Characterization of Glasses in Impact Breccia Dykes at the Mistastin Lake Impact Structure Labrador [Oral presentation #2588]. 42nd Lunar and Planetary Science Conference 2012, Houston, TX.
G.R. Osinski, A.C. Singleton, A. Ozaruk, J.R. Hansen. New Investigations of the Gow Lake Impact Structure, Saskatchewan, Canada: Impact Melt Rocks, Astronaut Training, and More [Oral presentation #2367]. 42nd Lunar and Planetary Science Conference 2012, Houston, TX.
A. C. Singleton, G. R. Osinski, and D. Moser. Effects of Shock Metamorphism on Zircons from the Haughton Impact Structure. [Oral presentation #5142]. Metallurgical Society 2011, Montreal, QC.
G.R. Osinski, L. Preston, L. Ferrière, T. Prave, J. Parnell, A. Singleton, and A.E. Pickersgill. The Stac Fada “Impact Ejecta” Layer: Not What it Seems. [Oral presentation #5451]. Metallurgical Society 2011, Montreal, QC.
A. C. Singleton, G. R. Osinski, R. A. F. Grieve, and C. Shaver. Characterization of Impact Melt-Bearing Impactite Dykes from the Central Uplift of the Mistastin Lake Impact Structure, Labrador [Oral presentation #2250]. 42nd Lunar and Planetary Science Conference 2011, Houston, TX.