Hetzel, Almut et al. (2011): Geochemical environment of Cenomanian-Turonian black shale deposition at Wunstorf (northern Germany)

Leg/Site/Hole:
ODP 207
ODP 207 1258
Identifier:
2013-000403
georefid

10.1016/j.cretres.2011.03.004
doi

Creator:
Hetzel, Almut
Carl von Ossietzky University, Institute for Chemistry and Biology of the Marine Environment, Oldenburg, Germany
author

Maerz, Christian
University of Bremen, Germany
author

Vogt, Christoph
author

Brumsack, Hans-Juergen
author

Identification:
Geochemical environment of Cenomanian-Turonian black shale deposition at Wunstorf (northern Germany)
2011
Cretaceous Research
Elsevier, United Kingdom
32
4
480-494
Major- and minor- element determinations were carried out on a high-resolution sample set obtained from a sediment drill core at Wunstorf (N. Germany). This study interval includes the black shale-bearing Hesseltal Formation associated with the Oceanic Anoxic Event 2 (OAE 2), also referred to as Cenomanian-Turonian Boundary Event (CTBE). Seven black shale packages, each containing several black shale layers, were defined by elevated TOC values, with black shale packages 1-4 deposited during OAE 2. Packages 5-7 extend above the level of the positive carbon-isotope excursion defining OAE 2, indicating that conditions favouring organic carbon burial must have prevailed longer in the Wunstorf Basin than elsewhere. Geochemical analyses revealed no significant differences between black shale packages deposited during and after OAE 2. Enrichment patterns of sulphur, iron and redox-sensitive and sulphide-forming trace metals point to suboxic to anoxic conditions existing at the sediment-water interface during black shale deposition, whereas sulphidic conditions prevailed deeper in the sediment. Variations in element/Al ratios follow cyclic patterns which are interpreted to represent climatically-induced changes in sediment supply. Reduced vertical mixing led to water-column stratification and caused black shale deposition.
English
Serial
Coverage:Geographic coordinates:
North:52.2400
West:-54.4400East: 9.2900
South:9.2600

Isotope geochemistry; Stratigraphy; anaerobic environment; Atlantic Ocean; basin analysis; black shale; Borchterbeck Formation; burial; C-13/C-12; carbon; Cenomanian; Central Europe; chemical composition; chemical ratios; clastic rocks; Cretaceous; cyclostratigraphy; Demerara Rise; Eh; enrichment; Equatorial Atlantic; Europe; geochemistry; Germany; Hanover Germany; Hasseltal Formation; iron; isotope ratios; isotopes; Italy; Leg 207; lithostratigraphy; Lower Saxony Germany; major elements; Marches Italy; marine environment; Mesozoic; metals; North Atlantic; northern Germany; Northwest Atlantic; Ocean Drilling Program; ODP Site 1258; organic compounds; paleoenvironment; sedimentary rocks; Sohlde Formation; Southern Europe; spectra; stable isotopes; stratigraphic boundary; sulfur; total organic carbon; trace elements; Turonian; Upper Cretaceous; West Atlantic; Wunstorf Germany; X-ray fluorescence spectra;

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