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Oxygen and carbon isotope stratigraphy of the Palaeogene and Cretaceous limestones in the Bottaccione Gorge and the Contessa Highway sections, Umbria, Italy
Author(s) -
Corfield R.M.,
Cartlidge J.E.,
PremoliSilva I.,
Housley R.A.
Publication year - 1991
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 - 10.1111/j.1365-3121.1991.tb00171.x
Subject(s) - geology , diagenesis , paleontology , cretaceous , stratigraphy , paleogene , cenomanian , isotopes of oxygen , overprinting , isotopes of carbon , geochemistry , isotope , tectonics , physics , quantum mechanics
We have made oxygen and carbon isotope measurements on limestone samples of Albian to Eocene age recovered from the Bottaccione Gorge section in the Umbrian Apennines, central Italy. Additional measurements have been made on topmost Maastrichtian and Palaeocene sediments from the adjacent Contessa Highway section. Our data from the Bottaccione Gorge show 13 C maxima at the Cenomanian/Turonian boundary and during the Palaeocene, as well as a pronounced 13 C minimum 7 metres above the clay layer at the K/T boundary. Our data from the Contessa Highway show a 13 C minimum 9 metres above the K/T boundary clay. These minima are probably diagenetic artifacts. In the Bottaccione Gorge there is evidence for a hiatus in the early Middle Eocene. The Palaeocene of the Bottaccione Gorge appears to have been affected by slumping or faulting (in addition to the diagenetic overprinting) giving a spurious δ 13 C recovery after the K/T boundary, the Contessa Highway section appears to be more complete. The Coniacian‐Maastrictian is characterized by relatively stable 13 C values. Our data indicate an increase in δ 18 O (and therefore possible cooling) across the Cretaceous/Tertiary boundary in both the Bottaccione and Contessa Highway sections.