A new Miocene biostratigraphy for the northeastern North Atlantic; an integrated foraminferal, bolboformid, dinoflagellate and diatom zonation

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doi: 10.1127/0078-0421/2012/0025
Author(s): Anthonissen, Erik D.
Author Affiliation(s): Primary:
University of Oslo, Natural History Museum, Oslo, Norway
Volume Title: Newsletters on Stratigraphy
Source: Newsletters on Stratigraphy, 45(3), p.281-307. Publisher: Gebrüder Bornträger, Berlin-Stuttgart, Germany. ISSN: 0078-0421 CODEN: NLSGAO
Note: In English. 115 refs.; illus., incl. 2 tables
Summary: This study presents a new Miocene biostratigraphic synthesis for the high-latitude northeastern North Atlantic region. Via correlations to the bio-magnetostratigraphy and oxygen isotope records of Ocean Drilling Program and Deep Sea Drilling Project Sites, the ages of shallower North Sea deposits have been better constrained. The result has been an improved precision and documentation of the age designations of the existing North Sea foraminiferal zonal boundaries of King (1989) and Gradstein and Bäckström (1996). All calibrations have been updated to the Astronomically Tuned Neogene Time Scale (ATNTS) of Lourens et al. (2004). This improved Miocene biozonation has been achieved through: the updating of age calibrations for key micro fossil bioevents, identification of new events, and integration of new biostratigraphic data from a fora mini feral analysis of commercial wells in the North Sea and Norwegian Sea. The new zonation has been successfully applied to two commercial wells and an onshore research borehole. At these high latitudes, where standard zonal markers are often absent, integration of microfossil groups significantly improves temporal resolution. The new zonation comprises 11 Nordic Miocene (NM) Zones with an average duration of 1 to 2 million years. This multi-group combination of a total of 92 bioevents (70 foraminifers and bolboformids; 16 dinoflagellate cysts and acritarchs; 6 marine diatoms) facilitates zonal identification throughout the Nordic Atlantic region. With the highest proportion of events being of calcareous walled microfossils, this zonation is primarily suited to micropaleontologists. A correlation of this Miocene biostratigraphy with a re-calibrated oxygen isotope record for DSDP Site 608 suggests a strong correlation between Miocene planktonic microfossil turnover rates and the inferred paleoclimatic trends. Benthic foraminifera zonal boundaries appear to often coincide with Miocene global sequence boundaries. The biostratigraphic record is punctuated by four main stratigraphic hiati which show variation in their geographic and temporal extent. These are related to the following regional unconformities: basal Neogene, Lower/Middle Miocene ("mid-Miocene unconformity"), basal Upper Miocene and basal Messinian unconformities. Further coring of Neogene sections in the North Sea and Norwegian Sea may better constrain their extent and their effect on the biostratigraphic record.
Year of Publication: 2012
Research Program: DSDP Deep Sea Drilling Project
IPOD International Phase of Ocean Drilling
ODP Ocean Drilling Program
Key Words: 12 Stratigraphy, Historical Geology and Paleoecology; Acritarchs; Algae; Atlantic Ocean; Biostratigraphy; Bolboforma; Cenozoic; Clastic rocks; DSDP Site 608; Deep Sea Drilling Project; Diatoms; Dinoflagellata; Foraminifera; IPOD; Invertebrata; Leg 94; Microfossils; Miocene; Mudstone; Neogene; North Atlantic; Northeast Atlantic; Ocean Drilling Program; Paleo-oceanography; Paleoclimatology; Palynomorphs; Plantae; Problematic fossils; Problematic microfossils; Protista; Sandstone; Sedimentary rocks; Tertiary
Coordinates: N425012 N425013 W0230515 W0230515
Record ID: 2015053377
Copyright Information: GeoRef, Copyright 2017 American Geosciences Institute. Reference includes data from Geoline, Bundesanstalt fur Geowissenschaften und Rohstoffe, Hanover, Germany