Characterization and astronomically calibrated age of the first occurrence of Turborotalia frontosa in the Gorrondatxe section, a prospective Lutetian GSSP: implications for the Eocene time scale
Author(s)
Language
English
Obiettivo Specifico
1A. Geomagnetismo e Paleomagnetismo
Status
Published
JCR Journal
JCR Journal
Peer review journal
Yes
Journal
Issue/vol(year)
3/42 (2009)
Publisher
The Lethaia Foundation
Pages (printed)
255-264
Date Issued
2009
Abstract
The Gorrondatxe section, a prospective Lutetian Global Stratotype Section and Point
(GSSP), has recently been used as the master reference section to reassess the correlation
between Eocene magnetostratigraphic and calcareous planktonic biostratigraphic
scales. However, the exact calibration of some events remained ill defined, as they were thought to be missing in Gorrondatxe due to a fault. The most important missing
events were the first occurrence of the planktonic foraminifera Turborotalia frontosa
and the C22n/C21r chron boundary. Either might be a reliable correlation criterion for
the Ypresian/Lutetian boundary, as both approach the age of the original Lutetian
Stratotype. New studies allowed the identification of the former event 9 m above the Gorrondatxe fault, within magnetic polarity Chron C21r and calcareous nannofossil Zone CP12a. Distinctive test features that characterize the most primitive morphotype of T. frontosa are described. Despite the high turbidite content, recurrent pelagic limestone–marl couplets and bundles occur, whose formation was driven by precession and eccentricity astronomical cycles. The first occurrence of T. frontosa
was found 27 couplets and 5.5 bundles (60 m) below the first occurrence of the calcareous nannofossil Blackites inflatus, which is dated at 48 Ma. Hence, the age of the first occurrence of T. frontosa is estimated at 48.55 Ma, confirming that it is the most suitable planktonic foraminiferal correlation criterion for the Ypresian/Lutetian boundary. These results show that the stratigraphic interval missing due to the Gorrondatxe fault cannot be greater than a few metres and reinforce the value of this section as a prospective Lutetian GSSP.
(GSSP), has recently been used as the master reference section to reassess the correlation
between Eocene magnetostratigraphic and calcareous planktonic biostratigraphic
scales. However, the exact calibration of some events remained ill defined, as they were thought to be missing in Gorrondatxe due to a fault. The most important missing
events were the first occurrence of the planktonic foraminifera Turborotalia frontosa
and the C22n/C21r chron boundary. Either might be a reliable correlation criterion for
the Ypresian/Lutetian boundary, as both approach the age of the original Lutetian
Stratotype. New studies allowed the identification of the former event 9 m above the Gorrondatxe fault, within magnetic polarity Chron C21r and calcareous nannofossil Zone CP12a. Distinctive test features that characterize the most primitive morphotype of T. frontosa are described. Despite the high turbidite content, recurrent pelagic limestone–marl couplets and bundles occur, whose formation was driven by precession and eccentricity astronomical cycles. The first occurrence of T. frontosa
was found 27 couplets and 5.5 bundles (60 m) below the first occurrence of the calcareous nannofossil Blackites inflatus, which is dated at 48 Ma. Hence, the age of the first occurrence of T. frontosa is estimated at 48.55 Ma, confirming that it is the most suitable planktonic foraminiferal correlation criterion for the Ypresian/Lutetian boundary. These results show that the stratigraphic interval missing due to the Gorrondatxe fault cannot be greater than a few metres and reinforce the value of this section as a prospective Lutetian GSSP.
References
Aubry, M.P. 1986: Paleogene calcareous nannoplankton biostratigraphy
of Northwestern Europe. Palaeogeography, Palaeoclimatology,
Palaeoecology 55, 267–334.
Aubry, M.P. 1995: From chronology to stratigraphy: interpreting
the Lower and Middle Eocene stratigraphic record in the
Atlantic Ocean. In Berggren, W.A., Kent, D.V., Aubry, M.P. &
Hardenbol, J. (eds): Geochronology, Time Scales and Global
Stratigraphic Correlation. Society of Economic Paleontologists
and Mineralogists (SEPM) (Society for Sedimentary Geology)
Special Publication 54, 213–274. SEPM, Tulsa, Oklahoma.
Aubry, M.P., Berggren, W.A., Kent, D.V., Flynn, J.J., Klitgord, K.,
Obradovich, J.D. & Prothero, D.R. 1988: Paleogene geochronology:
an integrated approach. Paleoceanography 3, 707–742.
Berggren, W.A. 1969: Cenozoic chronostratigraphy, planktonic
foraminiferal zonation and the radiometric time scale. Nature
224, 1072–1075.
Berggren, W.A. 1972: A Cenozoic time-scale: some implications
for regional geology and paleobiogeography. Lethaia 5, 195–
215.
Berggren, W.A. & Pearson, P.N. 2005: A revised tropical to subtropical
Paleogene planktonic foraminiferal zonation. Journal
of Foraminiferal Research 35, 279–298.
Berggren, W.A., Kent, D.V., Flynn, J.J. & Van Couvering, J.A.
1985: Cenozoic geochronology. Geological Society of America
Bulletin 96, 1407–1418.
Berggren, W.A., Kent, D.V., Swisher, C.C.III & Aubry, M.P. 1995:
A revised Cenozoic geochronology and chronostratigraphy.
In Berggren, W.A., Kent, D.V., Aubry, M.P. & Hardenbol, J.
(eds): Geochronology, Time Scales and Global Stratigraphic
Correlation. Society of Economic Paleontologists and Mineralogists
(SEPM) (Society for Sedimentary Geology) Special
Publication 54, 129–212. SEPM, Tulsa, Oklahoma.
Bernaola, G., Orue-Etxebarria, X., Payros, A., Dinarès-Turell, J.,
Tosquella, J., Apellaniz, E. & Caballero, F. 2006: Biomagnetostratigraphic
analysis of the Gorrondatxe section (Basque
Country, western Pyrenees): its significance for the definition
of the Ypresian/Lutetian boundary stratotype. Neues Jahrbuch
fur Geologie und Palaontologie Abhandlungen 241, 67–109.
Bernaola, G., Baceta, J.I., Orue-Etxebarria, X., Alegret, L.,
Martin-Rubio, M., Arostegui, J. & Dinares-Turell, J. 2007:
Evidence of an abrupt environmental disruption during the
mid-Paleocene biotic event (Zumaia section, western Pyrenees).
Geological Society of America Bulletin 119, 785–795.
Blow, W.H. 1979: The Cenozoic Globigerinida: A Study of the
Morphology, Taxonomy, Evolutionary Relationships and the
Stratigraphical Distribution of Some Globigerinida (Mainly
Globigerinacea), 3 vols, 1413 pp. E.J. Brill, Leiden, The
Netherlands.
Bolli, H.M. 1957: Planktonic foraminifera from the Eocene Navet
and San Fernando formations of Trinidad, B.W.I. In Loeblich,
A.R. et al. (eds): Studies in Foraminifera. Bulletin of the United
States National Museum 215, 155–172. Smithsonian Institution,
Washington.
Cavelier, C. & Pomerol, C. 1986: Stratigraphy of the Paleogene.
Bulletin de la Société Géologique de France 8, 255–265.
Dinarès-Turell, J. & Dekkers, M. 1999: Inferred multistage diagenetic
pathway for the Early Pliocene Trubi marls at Punta di
Maiata (southern Sicily): paleomagnetic and rock-magnetic
observations. In Tarling, D.H. & Turner, P. (eds): Palaeomagnetism
and Diagenesis in Sediments. Geological Society of London,
Special Publication 15, 53–69. Geological Society of London,
London, UK.
Dinarès-Turell, J., Baceta, J.I., Pujalte, V., Orue-Etxebarria, X. &
Bernaola, G. 2002: Magnetostratigraphic and cyclostratigraphic
calibration of a prospective Paleocene/Eocene stratotype
at Zumaia (Basque Basin, northern Spain). Terra Nova 14,
371–378.
Dinarès-Turell, J., Baceta, J.I., Pujalte, V., Orue-Etxebarria, X.,
Bernaola, G. & Lorito, S. 2003: Untangling the Paleocene climate:
an astronomically calibrated Lower Paleocene magnetostratigraphy
and biostratigraphy at Zumaia (Basque basin, Northern
Spain). Earth and Planetary Science Letters 216, 483–500.
Dinarès-Turell, J., Baceta, J.I., Bernaola, G., Orue-Etxebarria, X.
& Pujalte, V. 2007: Closing the Mid-Paleocene gap: toward a
complete astronomically tuned Paleocene Epoch and Selandian
and Thanetian GSSPs at Zumaia (Basque Basin, W Pyrenees).
Earth and Planetary Science Letters 262, 450–467.
Gradstein, F.M., Ogg, J.G. & Smith, A.G. 2004: A Geologic Time Scale
2004, 589 pp. Cambridge University Press, Cambridge, UK.
Hardenbol, J. & Berggren, W.A. 1978: A new Paleogene numerical
time scale. In Cohee, G.V., Giaessner, M.F. & Hedberg, H.D.
(eds): Contributions to the Geologic Time Scale. American
Association of Petroleum Geologists (AAPG), Studies in Geology
6, 213–234. AAPG, Tulsa, Oklahoma.
Larrasoaña, J.C., Gonzalvo, C., Molina, E., Monechi, S., Ortiz, S.,
Tori, F. & Tosquella, J. 2008: Integrated magnetobiochronology
of the Early/Middle Eocene transition at Agost (Spain): implications
for defining the Ypresian/Lutetian boundary stratotype.
Lethaia 41, 395–415.
Martini, E. 1970: Standard Palaeogene calcareous nannoplankton
zonation. Nature 226, 560–561.
Odin, G.S. & Luterbacher, H. 1992: The age of Paleogene Stage
boundaries. Neues Jahrbuch fur Geologie und Palaontologie
Abhandlungen 186, 21–48.
Okada, H. & Bukry, D. 1980: Supplementary modification and
introduction of code numbers to the low-latitude coccolith
biostratigraphic zonation (Bukry, 1973; 1975). Marine Micropaleontology
5, 321–325.
Orue-Etxebarria, X. 1985: Descripción de dos nuevas especies de
foraminíferos planctónicos en el Eoceno costero de la provincia
de Bizkaia. Revista Española de Micropaleontología 17, 467–
477.
Orue-Etxebarria, X. & Apellaniz, E. 1985: Estudio del límite Cusiense-
Luteciense en la costa vizcaína por medio de los foraminíferos
planctónicos. Newsletters on Stratigraphy 15, 1–12.
Orue-Etxebarria, X., Payros, A., Bernaola, G., Dinarès-Turell, J.,
Tosquella, J., Apellaniz, E. & Caballero, F. 2006: The Ypresian/
Lutetian boundary at the Gorrondatxe beach section (Basque
Country, W Pyrenees): Mid-conference excursion guidebook of the
International Meeting on Climate and Biota of the Early Paleogene,
34 pp. University of the Basque Country, Bilbao, Spain.
Payros, A., Orue-Etxebarria, X. & Pujalte, V. 2006: Covarying
sedimentary and biotic fluctuations in Lower-Middle Eocene
Pyrenean deep-sea deposits: palaeoenvironmental implications.
Palaeogeography, Palaeoclimatology, Palaeoecology 234,
258–276.
Payros, A., Bernaola, G., Orue-Etxebarria, G., Dinarès-Turell, J.,
Tosquella, J. & Apellaniz, E. 2007: Reassessment of the Early-
Middle Eocene biomagnetochronology based on evidence from
the Gorrondatxe section (Basque Country, western Pyrenees).
Lethaia 40, 183–195.
Pearson, P.N., Premec-Fucek, V. & Premoli-Silva, I. 2006:
Taxonomy, biostratigraphy, and phylogeny of Eocene
Turborotalia. In Pearson, P.N., Olsson, R.K., Huber, B.T.,
Hemleben, C. & Berggren, W.A. (eds): Atlas of Eocene Planktonic
Foraminifera. Cushman Foundation Special Publication
41, 433–460. Cushman Foundation, Harvard, Cambridge,
Massachusetts.
Pujalte, V., Baceta, J.I., Orue-Etxebarria, X. & Payros, A. 1998:
Paleocene strata of the Basque Country, western Pyrenees,
Northern Spain: facies and sequence development in a
deep-water starved basin. In de Graciansky, P.C., Hardenbol, J.,
Jacquin, T. & Vail, P. (eds): Mesozoic and Cenozoic Sequence
Stratigraphy of European Basins. Society of Economic Paleontologists
and Mineralogists (SEPM) (Society for Sedimentary
Geology) Special Publication 60, 311–325. SEPM, Tulsa,
Oklahoma.
Rodríguez-Lázaro, J. & García-Zarraga, E. 1996: Paleogene deepmarine
ostracodes from the Basque Basin. In Keen, M.C. (ed.):
Proceedings of the 2nd European Ostracodologists Meeting at
Glasgow, 1993, 79–85. British Micropalaeontological Society,
London.
Serra-Kiel, J., Hottinger, L., Caus, E., Drobne, K., Ferrandez, C.,
Jauhri, A.K., Less, G., Pavlovec, R., Pignatti, J., Samso, J.M.,
Schaub, H., Sirel, E., Strougo, A., Tambareau, Y., Tosquella, J.
& Zakrevskaya, E. 1998: Larger foraminiferal biostratigraphy
of the Tethyan Paleocene and Eocene. Bulletin de la Societe
Geologique de France 169, 281–299.
Stainforth, R.M., Lamb, J.L., Luterbacher, H., Beard, J.H. &
Jeffords, R.M. 1975: Cenozoic planktonic foraminifera zonation
and characteristics of index forms. University of Kansas Paleontological
Contributions, Lawrence 62, 1–425.
Subbotina, N.N. 1953: Iskopaemye foraminifery SSRS (Globigerinidy,
Khantkenininidy i Globorotaliidy). Trudy Vsesoyznogo
Nauchno-Issledovatel’skogo Geologorazvedochnogo Instituta
(VNIGRI) 76, 1–296.
Zachos, J., Pagani, M., Sloan, L., Thomas, E. & Billups, K. 2001:
Trends, rhythms, and aberrations in the global climate 65 Ma
to Present. Science 292, 686–693.
of Northwestern Europe. Palaeogeography, Palaeoclimatology,
Palaeoecology 55, 267–334.
Aubry, M.P. 1995: From chronology to stratigraphy: interpreting
the Lower and Middle Eocene stratigraphic record in the
Atlantic Ocean. In Berggren, W.A., Kent, D.V., Aubry, M.P. &
Hardenbol, J. (eds): Geochronology, Time Scales and Global
Stratigraphic Correlation. Society of Economic Paleontologists
and Mineralogists (SEPM) (Society for Sedimentary Geology)
Special Publication 54, 213–274. SEPM, Tulsa, Oklahoma.
Aubry, M.P., Berggren, W.A., Kent, D.V., Flynn, J.J., Klitgord, K.,
Obradovich, J.D. & Prothero, D.R. 1988: Paleogene geochronology:
an integrated approach. Paleoceanography 3, 707–742.
Berggren, W.A. 1969: Cenozoic chronostratigraphy, planktonic
foraminiferal zonation and the radiometric time scale. Nature
224, 1072–1075.
Berggren, W.A. 1972: A Cenozoic time-scale: some implications
for regional geology and paleobiogeography. Lethaia 5, 195–
215.
Berggren, W.A. & Pearson, P.N. 2005: A revised tropical to subtropical
Paleogene planktonic foraminiferal zonation. Journal
of Foraminiferal Research 35, 279–298.
Berggren, W.A., Kent, D.V., Flynn, J.J. & Van Couvering, J.A.
1985: Cenozoic geochronology. Geological Society of America
Bulletin 96, 1407–1418.
Berggren, W.A., Kent, D.V., Swisher, C.C.III & Aubry, M.P. 1995:
A revised Cenozoic geochronology and chronostratigraphy.
In Berggren, W.A., Kent, D.V., Aubry, M.P. & Hardenbol, J.
(eds): Geochronology, Time Scales and Global Stratigraphic
Correlation. Society of Economic Paleontologists and Mineralogists
(SEPM) (Society for Sedimentary Geology) Special
Publication 54, 129–212. SEPM, Tulsa, Oklahoma.
Bernaola, G., Orue-Etxebarria, X., Payros, A., Dinarès-Turell, J.,
Tosquella, J., Apellaniz, E. & Caballero, F. 2006: Biomagnetostratigraphic
analysis of the Gorrondatxe section (Basque
Country, western Pyrenees): its significance for the definition
of the Ypresian/Lutetian boundary stratotype. Neues Jahrbuch
fur Geologie und Palaontologie Abhandlungen 241, 67–109.
Bernaola, G., Baceta, J.I., Orue-Etxebarria, X., Alegret, L.,
Martin-Rubio, M., Arostegui, J. & Dinares-Turell, J. 2007:
Evidence of an abrupt environmental disruption during the
mid-Paleocene biotic event (Zumaia section, western Pyrenees).
Geological Society of America Bulletin 119, 785–795.
Blow, W.H. 1979: The Cenozoic Globigerinida: A Study of the
Morphology, Taxonomy, Evolutionary Relationships and the
Stratigraphical Distribution of Some Globigerinida (Mainly
Globigerinacea), 3 vols, 1413 pp. E.J. Brill, Leiden, The
Netherlands.
Bolli, H.M. 1957: Planktonic foraminifera from the Eocene Navet
and San Fernando formations of Trinidad, B.W.I. In Loeblich,
A.R. et al. (eds): Studies in Foraminifera. Bulletin of the United
States National Museum 215, 155–172. Smithsonian Institution,
Washington.
Cavelier, C. & Pomerol, C. 1986: Stratigraphy of the Paleogene.
Bulletin de la Société Géologique de France 8, 255–265.
Dinarès-Turell, J. & Dekkers, M. 1999: Inferred multistage diagenetic
pathway for the Early Pliocene Trubi marls at Punta di
Maiata (southern Sicily): paleomagnetic and rock-magnetic
observations. In Tarling, D.H. & Turner, P. (eds): Palaeomagnetism
and Diagenesis in Sediments. Geological Society of London,
Special Publication 15, 53–69. Geological Society of London,
London, UK.
Dinarès-Turell, J., Baceta, J.I., Pujalte, V., Orue-Etxebarria, X. &
Bernaola, G. 2002: Magnetostratigraphic and cyclostratigraphic
calibration of a prospective Paleocene/Eocene stratotype
at Zumaia (Basque Basin, northern Spain). Terra Nova 14,
371–378.
Dinarès-Turell, J., Baceta, J.I., Pujalte, V., Orue-Etxebarria, X.,
Bernaola, G. & Lorito, S. 2003: Untangling the Paleocene climate:
an astronomically calibrated Lower Paleocene magnetostratigraphy
and biostratigraphy at Zumaia (Basque basin, Northern
Spain). Earth and Planetary Science Letters 216, 483–500.
Dinarès-Turell, J., Baceta, J.I., Bernaola, G., Orue-Etxebarria, X.
& Pujalte, V. 2007: Closing the Mid-Paleocene gap: toward a
complete astronomically tuned Paleocene Epoch and Selandian
and Thanetian GSSPs at Zumaia (Basque Basin, W Pyrenees).
Earth and Planetary Science Letters 262, 450–467.
Gradstein, F.M., Ogg, J.G. & Smith, A.G. 2004: A Geologic Time Scale
2004, 589 pp. Cambridge University Press, Cambridge, UK.
Hardenbol, J. & Berggren, W.A. 1978: A new Paleogene numerical
time scale. In Cohee, G.V., Giaessner, M.F. & Hedberg, H.D.
(eds): Contributions to the Geologic Time Scale. American
Association of Petroleum Geologists (AAPG), Studies in Geology
6, 213–234. AAPG, Tulsa, Oklahoma.
Larrasoaña, J.C., Gonzalvo, C., Molina, E., Monechi, S., Ortiz, S.,
Tori, F. & Tosquella, J. 2008: Integrated magnetobiochronology
of the Early/Middle Eocene transition at Agost (Spain): implications
for defining the Ypresian/Lutetian boundary stratotype.
Lethaia 41, 395–415.
Martini, E. 1970: Standard Palaeogene calcareous nannoplankton
zonation. Nature 226, 560–561.
Odin, G.S. & Luterbacher, H. 1992: The age of Paleogene Stage
boundaries. Neues Jahrbuch fur Geologie und Palaontologie
Abhandlungen 186, 21–48.
Okada, H. & Bukry, D. 1980: Supplementary modification and
introduction of code numbers to the low-latitude coccolith
biostratigraphic zonation (Bukry, 1973; 1975). Marine Micropaleontology
5, 321–325.
Orue-Etxebarria, X. 1985: Descripción de dos nuevas especies de
foraminíferos planctónicos en el Eoceno costero de la provincia
de Bizkaia. Revista Española de Micropaleontología 17, 467–
477.
Orue-Etxebarria, X. & Apellaniz, E. 1985: Estudio del límite Cusiense-
Luteciense en la costa vizcaína por medio de los foraminíferos
planctónicos. Newsletters on Stratigraphy 15, 1–12.
Orue-Etxebarria, X., Payros, A., Bernaola, G., Dinarès-Turell, J.,
Tosquella, J., Apellaniz, E. & Caballero, F. 2006: The Ypresian/
Lutetian boundary at the Gorrondatxe beach section (Basque
Country, W Pyrenees): Mid-conference excursion guidebook of the
International Meeting on Climate and Biota of the Early Paleogene,
34 pp. University of the Basque Country, Bilbao, Spain.
Payros, A., Orue-Etxebarria, X. & Pujalte, V. 2006: Covarying
sedimentary and biotic fluctuations in Lower-Middle Eocene
Pyrenean deep-sea deposits: palaeoenvironmental implications.
Palaeogeography, Palaeoclimatology, Palaeoecology 234,
258–276.
Payros, A., Bernaola, G., Orue-Etxebarria, G., Dinarès-Turell, J.,
Tosquella, J. & Apellaniz, E. 2007: Reassessment of the Early-
Middle Eocene biomagnetochronology based on evidence from
the Gorrondatxe section (Basque Country, western Pyrenees).
Lethaia 40, 183–195.
Pearson, P.N., Premec-Fucek, V. & Premoli-Silva, I. 2006:
Taxonomy, biostratigraphy, and phylogeny of Eocene
Turborotalia. In Pearson, P.N., Olsson, R.K., Huber, B.T.,
Hemleben, C. & Berggren, W.A. (eds): Atlas of Eocene Planktonic
Foraminifera. Cushman Foundation Special Publication
41, 433–460. Cushman Foundation, Harvard, Cambridge,
Massachusetts.
Pujalte, V., Baceta, J.I., Orue-Etxebarria, X. & Payros, A. 1998:
Paleocene strata of the Basque Country, western Pyrenees,
Northern Spain: facies and sequence development in a
deep-water starved basin. In de Graciansky, P.C., Hardenbol, J.,
Jacquin, T. & Vail, P. (eds): Mesozoic and Cenozoic Sequence
Stratigraphy of European Basins. Society of Economic Paleontologists
and Mineralogists (SEPM) (Society for Sedimentary
Geology) Special Publication 60, 311–325. SEPM, Tulsa,
Oklahoma.
Rodríguez-Lázaro, J. & García-Zarraga, E. 1996: Paleogene deepmarine
ostracodes from the Basque Basin. In Keen, M.C. (ed.):
Proceedings of the 2nd European Ostracodologists Meeting at
Glasgow, 1993, 79–85. British Micropalaeontological Society,
London.
Serra-Kiel, J., Hottinger, L., Caus, E., Drobne, K., Ferrandez, C.,
Jauhri, A.K., Less, G., Pavlovec, R., Pignatti, J., Samso, J.M.,
Schaub, H., Sirel, E., Strougo, A., Tambareau, Y., Tosquella, J.
& Zakrevskaya, E. 1998: Larger foraminiferal biostratigraphy
of the Tethyan Paleocene and Eocene. Bulletin de la Societe
Geologique de France 169, 281–299.
Stainforth, R.M., Lamb, J.L., Luterbacher, H., Beard, J.H. &
Jeffords, R.M. 1975: Cenozoic planktonic foraminifera zonation
and characteristics of index forms. University of Kansas Paleontological
Contributions, Lawrence 62, 1–425.
Subbotina, N.N. 1953: Iskopaemye foraminifery SSRS (Globigerinidy,
Khantkenininidy i Globorotaliidy). Trudy Vsesoyznogo
Nauchno-Issledovatel’skogo Geologorazvedochnogo Instituta
(VNIGRI) 76, 1–296.
Zachos, J., Pagani, M., Sloan, L., Thomas, E. & Billups, K. 2001:
Trends, rhythms, and aberrations in the global climate 65 Ma
to Present. Science 292, 686–693.
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