English
 
Privacy Policy Disclaimer
  Advanced SearchBrowse

Item

ITEM ACTIONSEXPORT

Released

Conference Paper

A precise and accurate "astronomical" age of the Ries impact crater, Germany: A cautious note on argon dating of impact material

Authors
/persons/resource/rocholl

Rocholl,  A.       
0 Pre-GFZ, Departments, GFZ Publication Database, Deutsches GeoForschungsZentrum;

Ovtcharova,  M.
External Organizations (TEMPORARY!);

Schaltegger,  U.
External Organizations (TEMPORARY!);

Wijbrans,  J.
External Organizations (TEMPORARY!);

Pohl,  J.
External Organizations (TEMPORARY!);

Harzhauser,  M.
External Organizations (TEMPORARY!);

Prieto,  J.
External Organizations (TEMPORARY!);

Ulbig,  A.
External Organizations (TEMPORARY!);

Boehme,  M.
External Organizations (TEMPORARY!);

External Resource
Fulltext (restricted access)
There are currently no full texts shared for your IP range.
Fulltext (public)
There are no public fulltexts stored in PuRe
Supplementary Material (public)
There is no public supplementary material available
Citation

Rocholl, A., Ovtcharova, M., Schaltegger, U., Wijbrans, J., Pohl, J., Harzhauser, M., Prieto, J., Ulbig, A., Boehme, M. (2011): A precise and accurate "astronomical" age of the Ries impact crater, Germany: A cautious note on argon dating of impact material, (Geophysical Research Abstracts ; Vol. 13, EGU2011-13322-7, 2011), European Geosciences Union General Assembly (Vienna, Austria 2011).


Cite as: https://gfzpublic.gfz.de/pubman/item/item_2697899
Abstract
Accurate and precise dating of meteorite impacts is a prime intent of stratigraphic, paleoclimatic, and paleonto-logical research. Robust age estimates, however, exist only for 11 of 174 confirmed impacts structures (ref. 1) including the Ries crater in Germany, one of the best studied impact structures on Earth. This is probably also the impact site with the highest number of radiometric age determinations. So far, published ages are exclusively based on the analysis of impact-generated melts, i.e. suevite glass and/or moldavites (tektites) (e.g., ref. 2-7) and feldspar melt (ref. 8). However, despite more than 60 individual isotopic age data obtained during 50 years of research there is no consensus as to the accurate age of the impact. For example, 40Ar-39Ar ages range from 15.2 Ma (ref. 2) to 14.3 Ma (ref. 6,7), with the young ages representing most of the recent age determinations. Accordingly, the long-standing estimate of about 15 +- 0.2 Ma (ref. 2,3) has been criticized recently as being too old by more than 0.5 Ma (e.g., ref. 1, 5-8) and only confirmed once (ref. 9). Ages < 14.6 Ma, however, pose severe problems on geophysical and biostratigraphic interpretations. Most significantly and central to the discussion, they are in conflict with a reversed magnetic field during impact (ref. 10,11), because a normal magnetic field persisted from about 14.6 to 14.15 Ma (ref. 12), i.e. impact ages < 14.6 Ma are impossible from a paleomagnetic point of view.