Spike of pyrosynthetic polycyclic aromatic hydrocarbons associated with an abrupt decrease in δ13C of a terrestrial biomarker at the Cretaceous-Tertiary boundary at Caravaca, Spain

Tetsuya Arinobu, Ryoshi Ishiwatari, Kunio Kaiho, Marcos A. Lamolda

Research output: Contribution to journalArticle

71 Citations (Scopus)

Abstract

The first vertical high-resolution record of polycyclic aromatic hydrocarbons (PAHs) of pyrosynthetic origin and the corresponding δ13C profile of a terrestrial biomarker across the Cretaceous-Tertiary (K-T) boundary at Caravaca, Spain, reveals the following. In comparison with adjacent Cretaceous marlstones, the first thin horizon (0 to +0.5 cm; 0 = the K-T boundary) of the boundary-clay layer is (1) enriched as much as 112 to 154 fold in typical pyrosynthetic PAHs such as coronene, benzo(g,h,i)perylene, and benzo(e)pyrene and (2) shows an abrupt δ13C decrease of 1.4‰-1.8‰ in terrestrial higher plant-derived n-C29 alkane. The spike of pyrosynthetic PAHs associated with an abrupt decrease in δ13C value of a terrestrial biomarker is interpreted to reflect the prevalence of extensive fires with subsequent δ13C decrease in atmospheric CO2. It is estimated that the geologically instantaneous combustion of ~18%-24% of the terrestrial above-ground biomass would be necessary to account for the measured negative isotopic shift at the K-T boundary, on the basis of carbon mass balance between terrestrial above-ground biomass and atmosphere.

Original languageEnglish
Pages (from-to)723-726
Number of pages4
JournalGeology
Volume27
Issue number8
DOIs
Publication statusPublished - 1999 Jan 1

ASJC Scopus subject areas

  • Geology

Fingerprint Dive into the research topics of 'Spike of pyrosynthetic polycyclic aromatic hydrocarbons associated with an abrupt decrease in δ<sup>13</sup>C of a terrestrial biomarker at the Cretaceous-Tertiary boundary at Caravaca, Spain'. Together they form a unique fingerprint.

  • Cite this