Lunar and Planetary Science XXXVI (2005) sess15.pdf Tuesday, March 15, 2005 IMPACTS: EJECTA EFFECTS 1:30 p.m. Salon A Chairs: O. S. Barnouin-Jha F. T. Kyte 1:30 p.m. Barnouin-Jha O. S. * Cintala M. J. Crawford D. A. Impact into Coarse Grained Spheres [#1585] In this study, we use experimental techniques to report on how coarse grained targets might influence ejecta excavation and crater shape. 1:45 p.m. Yamamoto S. * Okabe N. Kadono T. Sugita S. Matsui T. Measurements of Ejecta Velocity Distribution by a High-Speed Video Camera [#1600] We performed impact experiments into glass sphere targets in order to measure the velocity distribution of ejecta with velocities ranging from a few to tens of m/s. 2:00 p.m. Schönian F. * Tagle R. Stöffler D. Kenkmann T. Geology of Southern Quintana Roo (Mexico) and the Chicxulub Ejecta Blanket [#2389] In southern Quintana Roo (Mexico) the Chicxulub ejecta blanket is discontinuously filling a karstified pre-KT land surface. This suggests a completely new scenario for the geological evolution of the southern Yucatán Peninsula. 2:15 p.m. Kring D. A. * Showman A. P. Durda D. D. Global Winds and Aerosol Updrafts Created by the Chicxulub Impact Event [#1544] Impact-generated thermal contrasts in the atmosphere may have generated high-velocity winds aloft and at the Earth’s surface. 2:30 p.m. Kyte F. T. * Gersonde R. Kuhn G. Detailed Results on Analyses of Deposits of the Eltanin Impact, Recovered in Sediment Cores from Polarstern Expedition ANT-XVIII/5a [#2129] An expedition by the RV Polarstern in 2001 explored 80,000 km2 of ocean floor and recovered 16 sediment cores containing ejecta deposits from the Eltanin impact. Details of this deep-ocean impact and the most meteorite-rich locality on Earth are discussed. 2:45 p.m. Ohno S. * Sugita S. Kadono T. Ishibashi K. Igarashi G. Matsui T. An Experimental Method to Estimate the Chemical Reaction Rate in Vapor Clouds: An Application to the K/T Impact [#1794] We propose a new experimental method to estimate the chemical reaction rate in vapor clouds. We also apply the method to the redox reactions of sulfur oxides and discuss the implication of the results to the K/T event. 3:00 p.m. Sheffer A. * Melosh H. J. Why Moldavites are Reduced [#1468] We use an isentropic cooling path to model the formation and oxygen reduction of moldavite tektites. The cooling path is inherently reducing, so no reducing agents are necessary. .