Meteoritics & Planetary Science 39, Nr 3, 425–451 (2004) Abstract available online at http://meteoritics.org Geology, petrography, shock petrography, and geochemistry of impactites and target rocks from the Kärdla crater, Estonia V. PUURA,1* H. HUBER, 2† J. KIRS,1 A. KÄRKI,3 K. SUUROJA, 4 K. KIRSIMÄE, 1 J. KIVISILLA, 4 A. KLEESMENT, 5 M. KONSA,5 U. PREEDEN, 1 S. SUUROJA, 5 and C. KOEBERL 2 1Institute of Geology, University of Tartu, Vanemuise strasse 46, 51014 Tartu, Estonia 2Department of Geological Sciences, University of Vienna, Althanstrasse 14, A-1090 Vienna, Austria 3Institute of Geosciences, University of Oulu, Box 3000, FIN-90401 Oulu, Finland 4Geological Survey of Estonia, Kadaka tee 80/82, 12618 Tallinn, Estonia 5Institute of Geology, Tallinn Technical University, Estonia pst. 7, 10143 Tallinn, Estonia †Present address: Institute of Geophysics and Planetary Physics, University of California Los Angeles, 595 Charles Young Drive, Los Angeles, California 90095, USA *Corresponding author. E-mail:
[email protected] (Received 20 December 2002; revision accepted 7 January 2004) Abstract–The Kärdla crater is a 4 km-wide impact structure of Late Ordovician age located on Hiiumaa Island, Estonia. The 455 Ma-old buried crater was formed in shallow seawater in Precambrian crystalline target rocks that were covered with sedimentary rocks. Basement and breccia samples from 13 drill cores were studied mineralogically, petrographically, and geochemically. Geochemical analyses of major and trace elements were performed on 90 samples from allochthonous breccias, sub-crater and surrounding basement rocks. The breccia units do not include any melt rocks or suevites. The remarkably poorly mixed sedimentary and crystalline rocks were deposited separately within the allochthonous breccia suites of the crater.