Trace element concentrations in the Mexico-Belize ejecta layer: A link between the Chicxulub impact and the global Cretaceous-Paleogene boundary

Research output: Chapter in Book/Report/Conference proceedingPaper in conference proceeding

Abstract

Four exposures of Chicxulub impact ejecta along the Mexico-Belize border have been sampled and analyzed for major and trace element abundances. The ejecta deposits consist of a lower spheroid bed, containing clay and dolomite spheroids, and an upper diamictite bed with boulders and clasts of limestone and dolomite. The matrix of both beds is composed of clay and micritic dolomite. The rare earth element (REE) compositions in the matrix of both units show strong similarities in concentrations and pattern. Furthermore, the Zr/TiO2 scatter plot shows a linear correlation indicating one source. These results indicate that the basal spheroid bed has the same source and was generated during the same event as the overlying diamictite bed, which lends support to a single-impact scenario for the Albion Formation ejecta deposits. The elevated concentrations of non-meteoritic elements such as Sb, As, U, and Zn in the matrix of the lower spheroid bed are regarded to have been derived from the sedimentary target rocks at the Chicxulub impact site. The positive Eu and Ce anomalies in clay concretion and in the matrix of the lower part of the spheroid bed in Albion Island quarry is probably related to processes involved in the impact, such as high temperature and oxidizing conditions. Analogous trace element anomalies have been reported from the distal Cretaceous-Paleogene (K/T) boundary clay layer at different sites. Thus, the trace element signals, reported herein, are regarded to support a genetic link between the Chicxulub impact, the ejecta deposits along the Mexico-Belize border, and the global K/T boundary layer.

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Subject classification (UKÄ) – MANDATORY

  • Geology
Original languageEnglish
Title of host publicationMeteoritics & Planetary Science
PublisherMeteoritical Society
Pages1871-1882
Volume42
Publication statusPublished - 2007
Publication categoryResearch
Peer-reviewedYes
EventWorkshop on Impact Craters as Indicators for Planetary Environmental Evolution and Astrobiology - Östersund, Sweden
Duration: 0001 Jan 2 → …

Publication series

Name
Number11
Volume42
ISSN (Print)1086-9379

Conference

ConferenceWorkshop on Impact Craters as Indicators for Planetary Environmental Evolution and Astrobiology
CountrySweden
CityÖstersund
Period0001/01/02 → …