Fachbereich 14 - Geowissenschaften
Institut für Planetologie
Analytische Planetologie

Geochemische Untersuchungen an Impaktlithologien des Chicxulub-Kraters, Mexko

Within the frame of the International Continental Drilling Project (ICDP), the scientific well YAXCOPOIL-1 was successfully drilled into the Chicxulub impact crater, Mexico. Our project is an essential part of the follow-up studies. We

• characterize target materials at the Chicxulub impact site via petrographic, geochemical and Rb-Sr, Sm-Nd isotope geochemical analyses of melt breccias, their clast content, and ejecta (YAX-1, UNAM and PEMEX cores; different K/T boundary sites), and
• study variations in sulfur content, and sulfur isotopic composition in impact-related lithologies. Major objectives of the project are to
  1. better constrain the basement at Yucatan, and hence, the pre-cursor material for ejecta in K/T boundary sequences, and for melt lithologies which stayed inside the final crater.
  2. The results of this systematic study allow reconstruction of the zones of melting and ejection, which are important parameters for quantifying cratering processes. Moreover, we expect an improved understanding of the mixing processes which occurred during impact melting and ejection. Sulfur concentration data may allow to estimate relative contributions of evaporites to the particular impactites.
  3. The sulfur isotope investigation provide the basis for deciphering impact-related chemical reactions that have contributed to the drastic environmental effects in the aftermath of the Chicxulub event.

The sulfur study is fundamental for verifying/falsifying the proposed role of evaporite degassing for the K/T mass extinction.

Drittmittelgeber:

Deutsche Forschungsgemeinschaft

Beteiligte Wissenschaftler:

Deutsch, A. (Leiter), Kettrup, B., Strauss, H.

Veröffentlichungen:

Kettrup, B., Deutsch, A. (2003): Geochemical variability of the Yucatan basement: constraints from crystalline clasts in Chicxulub impactites. Meteoritics & Planet. Sci., accepted for publication.

Strauss H., Deutsch, A. (2002): Sulfur bearing minerals in shock processes - the natural case: Popigai and Chicxulub. GSA Annual Meeting October 27-30, 2002, Denver, Co. Abstracts with Programs 239-15, p 545.