Sea & Coastal Research

Zee & Kust Onderzoek    

ZKO - Data & Information Portal

Publication details


General information

Author(s) : T. Bauersachs, B. Kremer, S. Schouten and J. S. S. Damste
Title : A biomarker and delta N-15 study of thermally altered Silurian cyanobacterial mats
Publication : Journal Article: Organic Geochemistry
Year : 2009


Keyword(s) :branched alkanes, carbon isotopes, earths oldest fossils, fatty-acids, life, marine, matter, natural abundance, organic nitrogen, sedimentary sequences
Abstracts : Early Silurian cherts from the Holy Cross and Bardzkie Mountains (Poland) contain abundant microfossils morphologically resembling contemporary cyanobacteria. Most of the organic matter preserved in the cherts is highly mature and extensively degraded because of biological decomposition and progressive thermal alteration. These processes may have changed the original morphology of the deposited microbial remains, so the microfossil origin could be easily misinterpreted. The cherts were therefore examined using organic geochemical and stable isotope techniques to provide support for the presence of cyanobacterial remains. The nitrogen isotopic composition of bulk sediments and extractable organic matter ranged from +0.1 parts per thousand, to -2.2 parts per thousand and from +1.8 parts per thousand to 1.7 parts per thousand, respectively. The delta N-15 values are thus in good agreement with a contribution of diazotrophic cyanobacteria for both locations. Biomarkers in the Holy Cross Mts. cherts included mid-chain branched monomethyl alkanes, indicative of a cyanobacterial contribution. However, Molecular fossils of a cyanobacterial origin were not detected in the Bardzkie Mts. cherts, most likely because of the greater maturity than those from the Holy Cross Mts. (C) 2008 Elsevier Ltd. All rights reserved.


For related items, please use the sub-menu's.
Project(s) :
  Cyanobacteria biogeochemical cycling  Role of cyanobacteria in past biogeochemical cycling
Dataset(s) :
Document(s) :