Mikael Calner
Professor
A new upper Middle Ordovician-Lower Silurian drillcore standard succession from Borenshult in Ostergotland, southern Sweden: 2. Significance of delta C-13 chemostratigraphy
Author
Summary, in English
A total of 239 isotope samples are used for establishing the delta C-13 chemostratigraphy in the upper Middle Ordovician to Lower Silurian succession in the approximately 70 m long Borenshult drillcore. The study interval starts in the upper Darriwilian Furudal Limestone and ends in the Rhuddanian Motala Formation. Four named delta C-13 excursions are recognized in 3-4 formations, namely the Guttenberg isotope carbon excursion (GICE) in the lower-middle Freberga Formation, the Kope (Rakvere) excursion in the uppermost Freberga Formation and possibly the Slandrom Formation, the Whitewater (Moe) excursion in the Lower Member of the Jonstorp Formation and the Hirnantian isotope carbon excursion (HICE) in the Loka Formation. The Middle Darriwilian isotope carbon excursion (MDICE) is missing in the drillcore and it is suggested that the study succession starts just above the interval of this excursion, which is in agreement with the range of MDICE in other Baltoscandic successions. The widespread Waynesville (Saunja) excursion may be cut out by the prominent unconformity below the Fjacka Shale. The two most conspicuous excursions are the GICE (peak value similar to+1.9 parts per thousand) and the HICE (peak value similar to+3.7 parts per thousand), whereas the other excursions are represented by relatively minor perturbations in the delta C-13 curve. The Borenshult drillcore chemostratigraphy, which has been closely tied to conodont biostratigraphy, is quite similar to that of Estonian drillcores and is useful for not only trans-Baltic but also trans-Atlantic correlations. It is the first drillcore-based delta C-13 chemostratigraphy from the Swedish Ordovician.
Department/s
- Lithosphere and Biosphere Science
Publishing year
2012
Language
English
Pages
39-63
Publication/Series
GFF
Volume
134
Issue
1
Document type
Journal article
Publisher
Taylor & Francis
Topic
- Geology
Keywords
- Middle and Upper Ordovician
- delta C-13 chemostratigraphy
- regional
- correlation
- Hirnantian excursion
- Guttenberg excursion
- Borenshult
- fauna
Status
Published
ISBN/ISSN/Other
- ISSN: 2000-0863