Bibliographic Citation
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Title | Cenomanian-Turonian oceanic anoxic event: Local perturbations on a global theme |
Creator/Author | Bralower, T.J. |
Publication Date | 1988 Jan 01 |
OSTI Identifier | OSTI ID: 6639169 |
Report Number(s) | CONF-880301- |
Resource Type | Conference |
Specific Type | Book |
Resource Relation | Annual meeting of the American Association of Petroleum Geologists; 20 Mar 1988; Houston, TX, USA |
Subject | 020200 -- Petroleum-- Reserves, Geology, & Exploration ;030200 -- Natural Gas-- Reserves, Geology, & Exploration; NATURAL GAS DEPOSITS-- GEOLOGY;PETROLEUM DEPOSITS-- GEOLOGY;WESTERN EUROPE-- NATURAL GAS DEPOSITS;WESTERN EUROPE-- PETROLEUM DEPOSITS; AGE ESTIMATION;BIOGEOCHEMISTRY;CARBON 13;CATAGENESIS;CRETACEOUS PERIOD;EXPLORATION;FOSSILS;OCEANIC CRUST;OCEANOGRAPHY;SEDIMENTARY BASINS;STRATIGRAPHY;TECTONICS |
Related Subject | CARBON ISOTOPES;CHEMISTRY;EARTH CRUST;EUROPE;EVEN-ODD NUCLEI;GEOCHEMISTRY;GEOLOGIC AGES;GEOLOGIC DEPOSITS;GEOLOGIC STRUCTURES;GEOLOGY;ISOTOPES;LIGHT NUCLEI;MESOZOIC ERA;MINERAL RESOURCES;NUCLEI;RESOURCES;STABLE ISOTOPES |
Description/Abstract | A high-resolution nannofossil zonation has been derived for the Cenomanian-Turonian (middle Cretaceous) boundary interval based on the investigation of numerous sections from Europe, North America, and Africa.^ This biostratigraphy allows accurate correlation of sections from shelf and pelagic environments, and the increased resolution helps solve paleo-oceanographic and sedimentologic problems in this interval.^ Boundary facies patterns are variable for numerous reasons.^ A simultaneous, widespread hiatus occurred in the latest Cenomanina and earliest Turonian in northwest Europe, an indirect result of peak marine transgression.^ In deep Tethys, produced carbonate was dissolved in undersaturated bottom waters of during early diagenesis.^ Few boundary sections are characterized by continuous carbonate deposition.^ An excursion in delta/sup 13/C, measured in many sections, has been associated with the burial of large amounts of marine organic carbon and is a potentially useful stratigraphic marker.^ This excursion commonly coincides with a facies change, lower ratios of coccolith carbonate to micrite, and poorer nannofossil preservation, and therefore is strongly diagenetically overprinted.^ Numerous nannofollil events indicate that the carbon excursion is slightly diachronous between sequences of the Western Interior and that the shift occurred distinctly later in this basin than in northwest Germany.^ The data obtained do not invalidate the concept of a Cenomanian-Turonian oceanic anoxic event, but show how local oceanographic perturbations have masked the global scenario.^ In particular, they indicate that carbon shifts may be basinal and not always oceanic phenomena, a conclusion that can be rationalized with overall sluggish middle Cretaceous circulation. |
Publisher | American Association of Petroleum Geologists,Tulsa, OK |
Country of Publication | United States |
Language | English |
Format | Pages: 1 |
Availability | American Association of Petroleum Geologists, P.O. Box 979, Tulsa, OK 74101. |
System Entry Date | 2001 May 13 |
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