Integrated stratigraphy and 40Ar/39Ar chronology of early middle Miocene sediments from DSDP Leg 42A, Site 372 (western Mediterranean)

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doi: 10.1016/j.palaeo.2007.09.013
Author(s): Abdul Aziz, H.; Di Stefano, A.; Foresi, L. M.; Hilgen, F. J.; Iaccarino, S. M.; Kuiper, K. F.; Lirer, F.; Salvatorini, G.; Turco, E.
Author Affiliation(s): Primary:
Ludwig Maximilian University of Munich, Department of Earth and Environmental Sciences, Munich, Federal Republic of Germany
Other:
University of Catania, Italy
University of Siena, Italy
Utrecht University, Netherlands
University of Parma, Italy
CNR, Istituto Ambiente Marino Costeiro, Italy
Volume Title: Palaeogeography, Palaeoclimatology, Palaeoecology
Source: Palaeogeography, Palaeoclimatology, Palaeoecology, 257(1-2), p.123-138. Publisher: Elsevier, Amsterdam, Netherlands. ISSN: 0031-0182 CODEN: PPPYAB
Note: In English. 55 refs.; illus., incl. 3 tables, sketch map
Summary: An integrated magneto-biostratigraphic framework is presented for Middle Miocene sediments of DSDP Site 372 located in the Western Mediterranean. Detailed biostratigraphic analysis shows a nearly complete sequence of early Middle Miocene calcareous plankton bioevents in the Mediterranean, including the LCO (Last Common Occurrence) of the nannofossil Sphenolithus heteromorphus which has been astronomically dated in the Ras il Pellegrin (RIP) section on Malta Island [Abels, H. A., Hilgen, F. J., Krijgsman, W., Kruk, R. W., Raffi, I., Turco, E., Zachariasse, W. J., 2005. Long-period orbital control on middle Miocene global cooling: integrated stratigraphy and astronomical tuning of the Blue Clay Formation on Malta, Paleoceanography, 20, PA4012. doi: 10.1029/2004PA001129. 11 pp]. Thermal demagnetization of discrete samples revealed a characteristic low-temperature component with dual polarities despite a weak paleomagnetic signal. The resultant magnetostratigraphic record, combined with the calcareous plankton biostratigraphy, is straightforwardly correlated to the geomagnetic polarity time scale (CK95) of Cande and Kent [Cande, S. C., Kent, D. V., 1995. Revised calibration of the Geomagnetic Polarity Time Scale for the Late Cretaceous and Cenozoic, J. Geophys. Res., 100, 6093-6095] and the Astronomical Tuned Neogene Time Scale (ATNTS04) of Lourens et al. [Lourens, L. J., Hilgen, F. J., Laskar, J., Shackleton, N. J., Wilson, D., 2004. The Neogene Period. In: Gradstein F. M., Ogg J. G., Smith A. G. (Eds.), A Geologic Time Scale, Cambridge Univ. Press, pp. 409-440]. The subchrons recorded in Site 372 succession range from C5Br up to C5AAr. To confirm the magnetostratigraphic calibration, 40Ar/39Ar dating was performed on feldspar of two volcanic ash layers. The radio-isotopic dating indicates a younger age for these two ash layers compared to the magnetostratigraphic calibrated ages according to the CK95 and ATNTS04 age models. However, if the astronomically calibrated age of 28.21±0.04 Ma is used for the Fish Canyon standard (FCs), the age for the older ash layer exactly matches its ATNTS04 age. Ages for bioevents were calculated assuming constant sedimentation rates between magnetostratigraphic age-tie points. The S. heteromorphus LCO has an age of 13.54 Ma and 13.63 Ma according to CK95 and ATNTS04, respectively, which is consistent with the astronomical tuned age of 13.65 Ma determined at RIP section [Abels, H. A., Hilgen, F. J., Krijgsman, W., Kruk, R. W., Raffi, I., Turco, E., Zachariasse, W. J., 2005. Long-period orbital control on middle Miocene global cooling: integrated stratigraphy and astronomical tuning of the Blue Clay Formation on Malta, Paleoceanography, 20, PA4012. doi:10.1029/2004PA001129. 11 pp]. We therefore conclude that the magnetostratigraphic calibration of DSDP Site 372 is correct and that, for the time being, this site can be considered as a reference section for the early Middle Miocene of the Mediterranean region. Abstract Copyright (2008) Elsevier, B.V.
Year of Publication: 2008
Research Program: DSDP Deep Sea Drilling Project
Key Words: 03 Geochronology; 12 Stratigraphy, Historical Geology and Paleoecology; Absolute age; Algae; Ar/Ar; Balearic Basin; Biostratigraphy; Boreholes; Cenozoic; Chronostratigraphy; Cores; Correlation; Cyclostratigraphy; DSDP Site 372; Dates; Deep Sea Drilling Project; Event stratigraphy; Foraminifera; Invertebrata; Leg 42A; Lithofacies; Lithostratigraphy; Magnetostratigraphy; Marine environment; Mediterranean Sea; Microfossils; Middle Miocene; Miocene; Nannofossils; Neogene; Paleomagnetism; Plantae; Protista; Reversals; Tertiary; West Mediterranean
Coordinates: N400152 N400154 E0044747 E0044747
Record ID: 2008064030
Copyright Information: GeoRef, Copyright 2017 American Geosciences Institute. Reference includes data from CAPCAS, Elsevier Scientific Publishers, Amsterdam, Netherlands