SUB Gflttlngen 204 582 27X The Manson Impact Structure, Iowa: Anatomy of an Impact Crater Edited by Christian Koeberl Institute of Geochemistry University of Vienna Althanstrasse 14 A-1090 Vienna, Austria and Raymond R. Anderson Iowa Department of Natural Resources Geological Survey Bureau 109TrowbridgeHall Iowa City, Iowa 52242-1319 PAPER 302 1996 Contents Preface v 1. Manson and Company: Impact Structures in the United States 1 Christian Koeberl and Raymond R. Anderson 2. A Brief History on Investigations of the Manson Impact Structure 31 Jack B. Hartung and Raymond R. Anderson 3. The Drilling of the 1991-1992 Geological Survey Bureau and U.S. Geological Survey Manson Impact Structure Research Cores 45 Raymond R. Anderson, Brian J. Witzke, and David J. Roddy 4. Gravity Investigation of the Manson Impact Structure, Iowa 89 J. B. Plescia 5. Structure of the Terrace Terrane, Manson Impact Structure, Iowa, Interpreted from High-Resolution Seismic Reflection Data 105 Dean Keiswetter, Ross Black, and Don Steeples 6. Sedimentary-Clast Breccias of the Manson Impact Structure 115 Brian J. Witzke and Raymond R. Anderson 7. Mineralogical, Petrological, and Geochemical Studies of Drill Core Samples from the Manson Impact Structure, Iowa 145 Christian Koeberl, Wolf Uwe Reimold, Alfred Kracher, Barbara Traxler, Andreas Vormaier, and Wilfried Korner 8. Petrography of Crystalline Clast Breccias from the Manson M-l Core 221 M. S. Bell, M. K. Reagan, R. R. Anderson, and C. T. Foster, Jr. 9. Preferential Feldspar Comminution in Impact Melt Breccias from the M-l Core of the Manson Impact Structure 235 M. K. Reagan, C. T. Foster, Jr., M. S. Bell, and R. R. Anderson in iv Contents 10. Petrography of Shocked Rocks from the Central Peak at the Manson Impact Structure 245 Nicholas M. Short and David P. Gold 11. A Transmission Electron Microscope Study of Shocked Quartz from the Manson Impact Structure 267 Hugues Leroux and Jean-Claude Doukhan 12. Geochemical Comparison of Four Cores from the Manson Impact Structure 275 Randy L. Korotev, Kaylynn M. Rockow, Bradley L. Jolliff, Larry A. Haskin, Peter McCarville, and Laura J. Crossey 13. Neodymium, Strontium, and Oxygen Isotope Investigation of the Target Stratigraphy and Impact Melt Rock from the Manson Impact Structure 317 Joel D. Blum, C. Page Chamberlain, Michael P. Hingston, and Christian Koeberl 14. Siderophile Element Concentrations in Drill Core Samples from the Manson Crater 325 Ernst Pernicka, Dietrich Kaether, and Christian Koeberl 75. Re-Os Isotope Study of Rocks from the Manson Impact Structure 331 Christian Koeberl and Steven B. Shirey 16. Preliminary Clay-Mineral Investigation of Some Impactites Recovered by Core Drilling in the Manson Impact Structure 341 Mary Clare Jones, George R. McCormick, and Raymond R. Anderson 17. Post-Impact Hydrothermal Alteration of the Manson Impact Structure 347 Peter McCarville and Laura J. Crossey 18. Fluid Inclusion Studies on Drill Core Samples from the Manson Impact Crater: Evidence for Post-Impact Hydrothermal Activity 377 R. H. Boer, W. U. Reimold, C. Koeberl, and S. E. Kesler 19. 40Ar/39Ar Thermochronology of Shocked Feldspars from the Manson Impact Structure 383 Peter Zeitler 20. Asymmetry of the Manson Impact Structure: Evidence for Impact Angle and Direction 397 Peter H. Schultz and Raymond R. Anderson 21. A Hypothesized Manson Impact Tsunami: Paleomagnetic and Stratigraphic Evidence in the Crow Creek Member, Pierre Shale 419 Maureen B. Steiner and Eugene M. Shoemaker 22. Deposition of the Crow Creek Member, Campanian, South Dakota and Nebraska 433 Brian J. Witzke, Richard H. Hammond, and Raymond R. Anderson Index 457.