Lunar and Planetary Science XXXIII (2002) sess33.pdf Tuesday, March 12, 2002 POSTER SESSION I 7:00–9:30 p.m. Gymnasium The Cratered Earth Ormö J. Rossi A. P. Komatsu G. Marchetti M. De Santis A. The Discovery of a Probable Well-preserved Impact Crater Field in Central Italy [#1075] We propose the first impact craters found in Italy. They form a crater field with about 17 craters in the range 2- 20 m, and a main crater 140x115 m. It represents a rare example of well-preserved explosion craters formed in unconsolidated targets. Rossi A. P. Seven Possible New Impact Structures in Western Africa Detected on ASTER Imagery [#1309] Seven possible impact structures have been found in W Africa on ASTER images. Their diameters vary from few hundreds of meters up to few kilometers. They are located in Mauritania, Mali and Niger, on a sedimentary or metamorphic bedrock. Miura Y. Hirota A. Gorton M. Kedves M. Impact-related Events on Active Tectonic Regions Defined by Its Age, Shocked Minerals and Compositions [#1231] New type of impact-related event is defined at active tectonic region by using semi-circular structure, bulk XRF compositions with mixed data, shocked quartz grains with the PDFs texture, and Fe-Ni content. Example is discussed in Takamatsu MKT crater in Japan. Krochuk R. V. Sharpton V. L. Overview of Terny Astrobleme (Ukrainian Shield) Studies [#1832] A brief summary of Terny astrobleme observations, including history, petrographic and mineralogical evidences of impact, structure of the crater at current erosion level. Pesonen L. J. Reimold W. U. Gibson R. L. Preliminary Paleomagnetic and Rock Magnetic Data of the Vredefort Structure, South Africa [#1187] Paleomagnetic data of the Witwatersrand Basin reveal an Archean remanence direction, Vredefort-Bushveld direction, and a 1.1 Ga direction. The central Vredefort Dome is characterized by extreme Q-values. Powars D. S. Johnson G. H. Edwards L. E. Horton J. W. Jr. Gohn G. S. Catchings R. D. McFarland E. R. Izett G. A. Bruce T. S. Levine J. S. Pierce H. A. An Expanded Chesapeake Bay Impact Structure, Eastern Virginia: New Corehole and Geophysical Data [#1034] Data from several deep coreholes, seismic reflection surveys, and surface mapping indicate that the buried Chesapeake Bay impact structure is wider (160 km, due to ~35-km-wide outer fracture zone) and deeper (2 miles) than previously reported. Hildebrand A. R. Pilkington M. Crater-Floor Exhalative (Crafex) Sulfide Deposits at the Chicxulub Crater, Yucatán, México [#2031] The melt sheet of the Chicxulub crater has been altered along fractures producing narrow zones of intense alteration that have a strong magnetic expression. These zones of hydrothermal alteration are believed to underlie exhalative mounds imaged by an offshore seismic line. McHone J. F. Roddy D. J. Shoemaker C. S. Williams K. K. Klemaszewski J. E. Spider Impact Structure, Western Australia Imaged with Space Shuttle Radar [#1990] Thirteen kilometer diameter Spider astrobleme in Western Australia was recorded in remarkable detail by imaging radar aboard the space shuttle Endeavour. Lunar and Planetary Science XXXIII (2002) sess33.pdf Mazur M. J. Hildebrand A. R. Hladiuk D. Schafer A. Pilkington M. The Steen River Crater Seismic Refraction Project [#1736] Rim uplift, slump blocks, CDC edge, central uplift, and inverted flap are indicated by refraction methods. The inverted flap also has a gravity high and may explain the puzzling partly annular gravity high ringing the CDC at the Chicxulub crater. Glass B. J. Lee P. Osinski G. Airborne Geomagnetic Investigations at the Haughton Impact Structure, Devon Island, Nunavut, Canada: New Results [#2008] The well-preserved ~23-Ma Haughton impact structure has an original rim diameter estimated at about 24 km. This work extends and completes the survey begun in 1999 to characterize the geomagnetic signature of Haughton. Mapping extent was about 75 × 60 km in order to clearly delineate regional features. Plescia J. B. Gravity Survey of the Rock Elm, Wisconsin Structure [#1573] Gravity data over the Rock Elm structure indicate that no anomaly associated with the structure is present. This suggests that it is either deeply eroded or not an impact structure. Öhman T. Kostama V-P. Aittola M. Raitala J. Badjukov D. Martian Analogues for Kara Impact Structure, Russia [#1270] Several craters in Hellas region show evidences of deformation by water. Some bear similarity to Kara impact structure, Russia. Comparative study of the impact craters provide information on Hellas’ geology as well as on the evolution of the Kara. Tsikalas F. Faleide J. I. Near-Field Erosional Features at the Mjølnir Impact Crater: The Role of Marine Sedimentary Target [#1296] The Mjølnir impact into a shallow marine sedimentary basin in the Barents Sea at ~142 Ma gave rise to subtle near-field erosional features in the crater vicinity as a result of the unconsolidated shaley sediments at the shallowest target levels. Wade S. Lichtenegger J. Barbieri M. Rudant J-P. Deffontaines B. Fruneau B. Master S. Application of Satellite Radar Interferometry in Enhancing the Morphology of the Velingara Structure, Casamance, Senegal [#1556] Interferometry of Synthetic Aperture Radar (SAR) imagery from the ERS-1and2 satellites has been used to produce a digital terrain model (DTM) of the 48 km-diameter Velingara structure in Casamance, Senegal, which strongly resembles an impact structure. Tornabene L. T. Ryan J. G. Stewart R. H. The Gatun Structure: A Petrographic and Geochemical Investigation into a Possible Tertiary Impact Structure near Gamboa, Republic De Panama [#1249] The occurrence of breccias that include both glass fragments, spherules, and phases with indicators of flow and plastic deformation, have been found within a circular feature near the Panama Canal — the Gatun structure. .