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Christian KOEBERL, Univ. Professor Dr. (Chair in Impact Research and Planetary Geology) |
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Address: Deputy Head, Department of Lithospheric Research University of Vienna Althanstrasse 14, 1090 Vienna, AUSTRIA
and: Director General, Natural History Museum Vienna |
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Impact Research, Geochemistry and
Cosmochemistry, Planetary Geology; Meteorites
Laboratories in research group: Gamma spectroscopy, multiparameter coincidence spectrometry, stable isotope mass spectrometry, sample preparation, optical microscopy |
| Members of the research group: |
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MADER Dieter, Mag. Dr. PITTARELLO, Lidia, M.Sc. Dr. BOAMAH Daniel, Dr. AMGAA Tsolmon, M.Sc. JALUFKA Dona HAGOS Miruts, M.Sc. IVANOV Boris, Gastprof. Dr. GOLDIN Tamara, Dr. BELLAVITA Mara, M.Sc. HUBER Matthew, M.Sc. LOSIAK Anna, M.Sc. GYOLLAI Ildiko, M.Sc. KASCHEL Barbara, Bakk. SCHENK Bettina, Dipl. Geol. Dr. |
2C184 |
dieter.mader@univie.ac.at |
+43 (1) 4277 53305
+43 (1) 4277 53104 +43 (1) 4277 53141 +43 (1) 4277 53316 +43 (1) 4277 53141 +43 (1) 4277 53308 +43 (1) 4277 53141 +43 (1) 4277 53104 +43 (1) 4277 53308 +43 (1) 4277 53308 +43 (1) 4277 53308 +43 (1) 4277-53316 +43 (1) 4277 53100 +43 (1) 4277 53305 |
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| Impact Research (click for more information) |
 Lonar crater (India) – 1.8 km in diameter (photo: C. Koeberl)
Impact is a unique, short-time,
high-energy geological process. The importance of impact cratering
on terrestrial planets is obvious from the abundance of craters on
their surfaces. On Earth, active geological processes rapidly
obliterate the cratering record. To date only about 170 impact
structures have been recognized on the Earth’s surface. The come in
various forms, shapes and sizes, from 300 km to less than 100 m in
diameter, from Recent to 2 billion years in age. Mineralogical,
petrographic, and geochemical criteria are used to identify the
impact origin of such structures or related ejecta layers. An aspect
of impact cratering that may be underestimated is the influence of
impacts on the geological and biological evolution of our own
planet. Even the impact of relatively small asteroids or comets can
have disastrous consequences for our civilization. There is a 1 in
10,000 chance that a large asteroid or comet 2 km in diameter (corresponding
to a crater of about 25-50 km in diameter) may collide with the
Earth during the next century, severely disrupting the ecosphere and
annihilating a large percentage of the Earth's population.
Understanding of impact structures, their formation processes, and
their consequences should be of interest not only to earth and
planetary scientists, but also to society in general. The biological
evolution of our planets is punctuated by mass extinction events, of
which the one 65 million years ago, which marks the
Cretaceous-Tertiary boundary, is probably the best known one.
Abundant impact debris marks this boundary, providing a clear link
with a major impact event. The Chicxulub impact structure in Mexico,
about 200 km in diameter, which resulted from the impact of an about
10-km-diameter asteroidal body, has been identified as the culprit.
Several other mass extinctions, most notably the Late Devonian,
Permian-Triassic, Triassic-Jurassic, and Jurassic-Cretaceous ones,
have been linked to possible impact events as well, although in
these cases the evidence is not (yet) strong enough to allow
unambiguous conclusions.
...more For a current list of terrestrial impact craters, see: http://www.unb.ca/passc/ImpactDatabase/ |
| current research projects: Drilling at the Bosumtwi meteorite impact crater, Ghana |
 The
10.5-km-diameter 1.07 Ma Bosumtwi impact crater was the subject of
an multidisciplinary and international drilling effort of the
International Continental Scientific Drilling Program (ICDP) from
July to October 2004. Sixteen different cores were drilled at six
locations within the lake, to a maximum depth of 540 m. A total of
about 2.2 km of core material was obtained. Desite of some technical
and logistical challenges, the project has been very successful and
the first scientific results became available in early 2006. As part
of this international project, the Austrian contribution in studying
the drill cores consists of geochemical, petrographic, mineralogic,
and petrophysical investigations....more |
| current research projects: Chesapeake Bay impact structure: ICDP/USGS deep drilling project |
 The
Chesapeake Bay Impact Structure Deep Drilling Project (CBIS Project)
completed its coring operations during September-December 2005 and
April-May 2006. Cores were collected continuously to a total depth
of 1,766 m. The recovered section consists of 1,322 m of impactites
beneath 444 m of post-impact continental-shelf sediments.The CBIS Project is a joint venture of the International Continental Scientific Drilling Program (ICDP) and the U.S. Geological Survey (USGS). Project activities began with a planning workshop in September 2003 that was funded by the ICDP, hosted by the USGS, and attended by 63 scientists from 10 countries. A resulting funding proposal to ICDP was accepted in late 2004, and additional drilling funds were authorized by the USGS. Field operations began with site preparation in July 2005, and coring began in September 2005. DOSECC, Inc., was the general contractor for the drilling operations throughout 2005. The NASA Science Mission Directorate, ICDP, and USGS provided important supplementary drilling funds in November-December 2005 that permitted coring of the deeper part of the impact structure. Studies of post-impact sediments were supported by the U.S. National Science Foundation (NSF), Earth Science Division, Continental Dynamics Program. Buried at shallow to moderate depths beneath continental-margin sediments in southeastern Virginia, USA (Fig. 1), the late Eocene Chesapeake Bay impact structure is among the largest and best preserved of the known impact structures on Earth (Poag et al., 2004). It is the second largest among only a handful of known impact structures that formed in a marine setting (surpassed in size only by the Chicxulub structure in Mexico, the subject of an ICDP drilling project in 2001-2002). It is the source of one of only four tektite strewn fields that are currently known on Earth, the North American tektite strewn field (Koeberl et al., 1996). The Chesapeake Bay impact structure consists of a 38-km-wide, strongly and deeply deformed central zone surrounded by a shallower outer zone of sediment collapse known as the annular trough. Collectively, these two zones have a diameter of about 85 km and a distinctive shape that is generally referred to as an “inverted sombrero.” ...more |
| Christian KOEBERL Althanstrasse 14 1090 Wien AUSTRIA phone: +43-1-4277-53110 fax: +43-1-4277-9534 |
