Status of the impact crater age database 1 2 3 F. Jourdan a* , P.R. Renne b,c , W.U. Reimold d 4 5 6 a Western Australian Argon Isotope Facility, Department of Applied Geology, Curtin 7 university of Technology, GPO Box U1987, Perth, WA 6845; Australia. 8 b Berkeley Geochronology Center; 2455 Ridge Rd., Berkeley, CA94709, USA 9 c Department of Earth and Planetary Science, University of California, Berkeley, CA94720, 10 USA 11 d Museum f. Natural History (Mineralogy), Humbold University Berlin, Invalidenstrasse 43, 12 10115 Berlin, Germany 13 14 *f.jourdan@curtin.edu.au 15 16 Abstract 17 18 The Earth impact crater database (http://www.unb.ca/passc/ImpactDatabase/ ) lists a total of 19 174 impact structures (early 2008). Most ages compiled in the database are based on dates 20 recommended in the most recent published papers about a given structure. Precise and 21 accurate age constraints are crucial for (1) correlating causes and effects on the bio- and 22 geosphere of catastrophic processes, (2) better constraining the impactor flux through 23 geological time and evaluation of potential impact periodicity, (3) calibrating the absolute 24 chronostratigraphic time scale, (4) calibrating the age of within-crater continental sedimentary 25 * Manuscript