Abstract
The impact of an extraterrestrial body 65.5. Ma caused the so-called Cretaceous/Paleogene (K/Pg) event that resulted in a mass extinction and rapid changes in the surface environment on Earth. Here we report changes in land vegetation and oceanic redox across the K/Pg boundary at Caravaca, southeastern Spain, using biomarkers. The results reveal that the basal 3-mm-thick layer of the K/Pg boundary clay is marked by a rapid increase in the concentration of terrestrial long-chain n-alkanes and dibenzofuran, indicating the destruction of land vegetation and an increase in the supply of terrestrial organic matter into the marine environment during the deposition of the K/Pg boundary clay. This layer also records a rapid increase in the concentration of dibenzothiophenes, which indicates a change in redox conditions from oxic to anoxic/euxinic conditions in the intermediate water over the seafloor. The low-oxygen conditions could have been caused by an increase in the influx of terrestrial organic matter into the ocean. A rapid increase in the concentration of retene and retene/cadalene occurred during the deposition of the upper part of the boundary clay 10. kyr after the mass extinction, indicating the recovery of conifers, which greatly decreased at the K/Pg boundary.
Original language | English |
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Pages (from-to) | 41-47 |
Number of pages | 7 |
Journal | Palaeogeography, Palaeoclimatology, Palaeoecology |
Volume | 369 |
DOIs | |
Publication status | Published - 2013 Jan 1 |
Keywords
- Anoxia
- Biomarker
- Cretaceous-Paleogene
- Dissolved oxygen
- Mass extinction
- Plant
- Recovery
- Vegetation
ASJC Scopus subject areas
- Oceanography
- Ecology, Evolution, Behavior and Systematics
- Earth-Surface Processes
- Palaeontology