Biostratigraphy, mineralogy and geochemistry of the Trabakua Pass and Ermua sections in Spain: Paleocene-Eocene transition

Marie Pierre Bolle, Thierry Adatte, Gerta Keller, Katharina Von Salis, Johannes Hunziker

Research output: Contribution to journalArticlepeer-review

20 Scopus citations

Abstract

Isotopic, geochemical and bulk mineralogical analyses in the Trabakua and Ermua sections, Basque Basin, reveal major changes across the Paleocene-Eocene transition. Expanded sedimentary records exhibit a gradual decrease of 1.0‰ in δ 13C values in the lower part of Zone P5 followed by a more rapid 3‰ negative excursion. The 3‰ δ 13C excursion is associated with an abrupt decrease in carbonate sedimentation, increased detrital flux and decreased grain size which suggest changes in marine/atmospheric currents and/or size and structure of the ocean carbon reservoir. The clays recognized at Trabakua record a deep burial diagenesis as indicated by two generations of chlorite, the presence of mixed-layers chlorite-smectite and illite-smectite, the absence of smectite and the near absence of kaolinite. The very low δ 18O values (<-3.5‰) throughout the Trabakua and Ermua sections reflect diagenetic alteration rather than paleotemperatures. Because of deep burial diagenesis and very poorly preserved microfossils, the Trabakua Pass and Ermua sections are not optimal potential stratotypes for the Paleocene-Eocene boundary.

Original languageEnglish (US)
Pages (from-to)1-25
Number of pages25
JournalEclogae Geologicae Helvetiae
Volume91
Issue number1
StatePublished - Sep 17 1998

All Science Journal Classification (ASJC) codes

  • Geology

Fingerprint Dive into the research topics of 'Biostratigraphy, mineralogy and geochemistry of the Trabakua Pass and Ermua sections in Spain: Paleocene-Eocene transition'. Together they form a unique fingerprint.

Cite this