44th Lunar and Planetary Science Conference (2013) sess506.pdf Friday, March 22, 2013 [F506] TERRESTRIAL IMPACT CRATERS: WHERE, WHEN, WHAT, HOW 8:30 a.m. Montgomery Ballroom Chairs: Michail Petaev Cassandra Marion 8:30 a.m. Mader M. M. * Osinski G. R. Tornabene L. L. Structural Geology of the Mistastin Lake Impact Structure, Labrador, Canada [#2517] The study summarizes the use of a high-quality digital terrain model to assess the structure and diameter of the ~28-km Mistastin Impact Structure in Labrador. 8:45 a.m. Young K. E. * Hodges K. V. van Soest M. C. Osinski G. R. Dating the Mistastin Lake Impact Structure, Labrador, Canada, Using Zircon (U-Th)/He Thermochronology [#2426] We report a new and slightly younger age for the Mistastin Lake impact structure using the (U-Th)/He system. 9:00 a.m. Pickersgill A. E. * Osinski G. R. Flemming R. L. Shock Metamorphism in Plagioclase from the Mistastin Lake Impact Structure, Canada [#2471] Anorthosites exhibiting PDFs in quartz, ubiquitous undulatory extinction, and a mosaic-patchy extinction pattern in plagioclase suggest low peak pressures. 9:15 a.m. Osinski G. R. * Abou-Aly S. Francis R. Hansen J. Marion C. L. et al. The Prince Albert Impact Structure, Northwest Territories, Canada: A New 28-km Diameter Complex Impact Structure [#2099] We confirm a new 28-km-diameter impact structure in Arctic Canada. It offers important insights into crater collapse and shatter cone formation. 9:30 a.m. Marion C. L. * Osinski G. R. Linnen R. L. Characterization of Hydrothermal Mineralization at the Prince Albert Impact Structure, Victoria Island, Canada [#1635] Mineralogical and fluid inclusion results from the Prince Albert impact structure are presented as evidence for a post-impact hydrothermal system. 9:45 a.m. Schmieder M. * Tohver E. Denyszyn S. Jourdan F. Haines P. W. Shock-Metamorphosed Zircons from the Acraman Impact Structure (South Australia) — Tracers of Multi-Stage Impact Crater Evolution [#1991] Complex crater evolution is recorded in melt rock-hosted zircons from the Acraman impact structure, South Australia. New SEM and U/Pb data are presented. 10:00 a.m. Anders D. * Osinski G. R. Grieve R. A. F. The Onaping Intrusion, Sudbury, Canada — An Impact Melt Origin and Relationship to the Sudbury Igneous Complex [#1637] The results of this study provide evidence that the Onaping Intrusion from the Sudbury impact structure is an impact melt and might be the roof rock of the SIC. 10:15 a.m. Raschke U. * Reimold W. U. Schmitt R. T. Petrography of the Impact Breccias from the ICDP-El´gygytgyn Drill Core, NE-Russia — A Focus on Melt Particles [#1340] Volcanic and impact-generated melt particles in impact breccias from the D1c ICDP drill core from the El’gygytgyn impact structure are discriminated. 44th Lunar and Planetary Science Conference (2013) sess506.pdf 10:30 a.m. Sturm S. * Wulf G. Jung D. Kenkmann T. The Ries Impact Crater: An Analogue to Double-Layer Rampart Craters on Mars [#1876] We concerned the question if the Ries Crater is comparable to martian double-layer ejecta craters by comparing the ejecta distribution outside the crater. 10:45 a.m. Goderis S. * Tagle R. Belza J. Smit J. Montanari A. et al. Can Siderophile Element Abundances and Ratios Across the K-Pg Boundary be Used to Discriminate Between Possible Types of Chondrites? [#2167] A revisit to platinum-group-element abundances across the Cretaceous-Paleogene boundary and implications for the nature of the projectile. 11:00 a.m. Moore J. R. * Hallock H. R. Chipman J. W. Sharma M. Iridium and Osmium Fluences Across the K-Pg Boundary Indicate a Small Impactor [#2405] Reconciling global iridium and osmium fluences associated with the K-Pg impact indicates that the Chicxulub impactor was relatively small (~320 Gt or less). 11:15 a.m. Hamann C. * Hecht L. Ebert M. Wirth R. Chemical Projectile-Target Interaction and Liquid Immiscibility in Impact Glass from the Wabar Craters, Saudi Arabia [#1522] This work investigates partitioning of iron meteorite matter in Wabar impact glass and shows that Wabar black melt/glass was formed by liquid immiscibility. 11:30 a.m. Petaev M. I. * Huang S. Jacobsen S. B. Zindler A. Large Platinum Anomaly in the GISP2 Ice Core: Evidence for a Cataclysm at the Bølling- Allerød/Younger Dryas Boundary? [#1046] A large Pt anomaly in the Greenland GISP2 ice core rules out a chondritic impact at ~12,900 years but does not rule out the Younger Dryas impact hypothesis. .