@article{93,
  author = {D. St{\"u}ben and U. Kramar and M. Harting and W. Stinnesbeck and G. Keller},
  title = {High-resolution geochemical record of Cretaceous-Tertiary boundary sections in Mexico: New constraints on the K/T and Chicxulub events},
  abstract = {<p>The investigation of eight Cretaceous{\textendash}Tertiary (K/T) sections in Mexico, based on major and trace element, platinum group element (PGE), stable isotope, and multivariate statistical analysis, reveals a complex depositional history across the Chicxulub and K/T boundary events. At the biostratigraphically determined K/T boundary, a minor but significant Ir-dominated PGE anomaly (0.2{\textendash} 0.8 ng/g) is present in most sections. This Ir anomaly originated from an impact event and is always stratigraphically and geochemically decoupled from the underlying spherule-rich ejecta deposit related to the Chicxulub event. In all sections examined, one to three glass spherule ejecta layers and one or two chondrite-dominated PGE anomalies are separated by a bioturbated siliciclastic deposit and/or hemipelagic marl, which indicates the occurrence of at least two impact events separated by a considerable amount of time. In addition, bentonite layers and Pt and Pd-dominated PGE anomalies below and above the K/T boundary indicate volcanic activity. Above the K/T boundary, reduced bioproductivity is documented by a decrease in the biogenically bound fraction of nutrients and fluctuating ratios of immobile elements (e.g., Ti/Zr). Variations in detrital elements reflect changes in the depositional environment. Carbon and oxygen isotope and trace element distribution patterns indicate a gradually changing climate during the latest Maastrichtian, an abrupt change at the K/T boundary, and a slight recovery during the lowermost Paleocene.\&nbsp; <a href="https://geoweb.princeton.edu/research/keller/pubs/Stuben_2004_Geochimica.pdf" target="_blank">PDF</a></p>
},
  year = {2005},
  journal = {Geochimica et Cosmochimica Acta},
  volume = {69},
  pages = {2559 - 2579},
  month = {Jan-05-2005},
  issn = {00167037},
  url = {http://linkinghub.elsevier.com/retrieve/pii/S0016703704008622},
  doi = {10.1016/j.gca.2004.11.003},
  language = {eng},
}