, Volume 34, Issue 2, pp 99–112

Stable carbon and oxygen isotopic compositions of recent charophyte oosporangia and water from Malham Tarn, U.K.: palaeontological implications

  • Timothy P. Jones
  • Steven M. Fortier
  • Allan Pentecost
  • Margaret E. Collinson

DOI: 10.1007/BF02180975

Cite this article as:
Jones, T.P., Fortier, S.M., Pentecost, A. et al. Biogeochemistry (1996) 34: 99. doi:10.1007/BF02180975


Charophyte oosporangia and water samples from a highly calcareous lake were measured for stable carbon and oxygen isotopic composition. The time period over which the oosporangia calcify is short, thus any biochemical relationship between the water and oosporangia"s calcite represents only one ‘time window’ (late Summer in Malham Tam). This important temporal restraint must also apply to interpretations of all fossil material measured. The δ18Oc of the charophyte oosporangia is deduced to be in equilibrium with the δ18Oω of the water for a given temperature. The δ13 Cc of the charophyte oosporangia was approximately 2.5 per mil lower than the δ13CDIC in the water we measured. With the release Of CO2 with phosphoric acid from the charophyte oosporangia, there was no significant difference in the δ18Oc values obtained, regardless of whether or not the carbonate was separated from the organic center, however δ13Cc values were marginally lower for carbonate plus organic center measurements. Our results indicate that fossil charophyte gyrogonites can be used to elucidate the geochemistry of the ancient water body in which they lived.

Key words

Characharophytesgyrogonitescarbonoxygenstable isotopespalaeolimnology

Copyright information

© Kluwer Academic Publishers 1996

Authors and Affiliations

  • Timothy P. Jones
    • 1
  • Steven M. Fortier
    • 3
  • Allan Pentecost
    • 5
  • Margaret E. Collinson
    • 6
  1. 1.Institut und Museum für Geologie und PaläontologieUniversität TübingenTübingenGermany
  2. 2.Department of Earth SciencesUniversity of Wales CardiffCardiffUK
  3. 3.Institut für Mineralogie, Petrologie und GeochemieUniversität TübingenTübingenGermany
  4. 4.Chemical & Analytical Sciences DivisionOak Ridge National LaboratoryOak RidgeUSA
  5. 5.Division of Life SciencesKing"s College London, University of LondonLondonUK
  6. 6.Geology Department, Royal HollowayUniversity of LondonEgham Hill, EghamUK