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Terrestrial carbon‐isotope records from coastal deposits (Algarve, Portugal): a tool for chemostratigraphic correlation on an intrabasinal and global scale
Author(s) -
Heimhofer Ulrich,
Hochuli Peter A.,
Burla Stefan,
Andersen Nils,
Weissert Helmut
Publication year - 2003
Publication title -
terra nova
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.353
H-Index - 89
eISSN - 1365-3121
pISSN - 0954-4879
DOI - 10.1046/j.1365-3121.2003.00447.x
Subject(s) - geology , cretaceous , aptian , isotopes of carbon , chemostratigraphy , paleontology , terrestrial plant , dominance (genetics) , cenomanian , structural basin , δ13c , stable isotope ratio , total organic carbon , ecology , chemistry , biochemistry , physics , quantum mechanics , gene , biology
The carbon‐isotope signature of terrestrial organic matter (OM) offers a valuable tool to develop stratigraphic correlations for near‐shore deposits. A mid‐Cretaceous coastal succession of the western Algarve Basin, Portugal, displays a marked negative δ 13 C excursion ranging from − 21.2‰ to − 27.8‰ in the Early Aptian followed by two shifts towards higher values (up to − 19.3‰) during the Early and Late Aptian, respectively. The dominance of cuticle and leaf debris in the bulk OM fraction is confirmed by optical studies, Rock‐Eval pyrolysis and by comparison with the δ 13 C signature of four different types of fossilized land‐plant particles. Correlation of two terrestrial δ 13 C bulk OM records from different study sites leads to a significant enhancement of the intrabasinal stratigraphic correlation within the Algarve Basin. Three prominent excursions in the Portuguese records can be correlated with existing δ 13 C curves from pelagic and terrestrial environments. The general carbon‐isotope pattern is superimposed by small‐scale fluctuations which can be explained by compositional variations within the OM.