GSSP for Thanetian Stage
Definition:
The base of the Thanetian Stage is defined in the sea-cliff along the
main beach of the coastal town Zumaia, Basque Country, northern Spain.
The GSSP is about 78m above the Cretaceous/Paleogene boundary. The
GSSP is defined at a level 2.8m or eight precession cycles above the
base of the core of the distinct clay-rich interval associated with
the Mid-Paleocene Biotic Event, and it corresponds to the base of
magnetochron C26n.
Location:
The GSSP of the Thanetian Stage is located along the main beach, of the coastal
town Zumaia, Basque Country, northern Spain at a latitude of 43° 17' 58.4"N, and
a longitude of 02° 15' 39.1"W. The GSSP for the Thanetian is about 78 m above
the Cretaceous/ Paleogene boundary.
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Sedimentology:
The lower part of the Itzurun Formation can be subdivided into a
lower, ca. 24m thick Member A and an upper, 52m thick Member B. The
boundary between the two members is 6.5m below the GSSP. The turbidite
intercalations of the marly Member A are mostly siliciclastic, whereas
in Member B, they are siliciclastic or mixed carbonatic-siliciclastic.
About 3 m above the limit between Member A and B of the Itzurun
Formation is a prominent dark, ca. 1m thick interval recording a
drastic decrease in CaCO3. This clay is interpreted as the
Mid-Paleocene Biotic Event
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Primary Markers:
The Thanetian GSSP corresponds to the base of magnetochron C26n.
Correlation Events:
Magnetic -- Base of Chron C26n
Notes on Derivation of Age:
Astronomical cycles in sediments scaled from base Paleocene, using base of
magnetic polarity chronozone C26n. Arbitrary 0.1 (2 precession cycles, plus the
base-Paleogene radiometric) uncertainty assigned to all estimates.
References:
Schmitz, B., Pujalte, V., Molina, E., Monechi, S., Orue-Etxebarria, X., Speijer,
R.P., Alegret, L., Apellaniz, E., Arenillas, I., Aubry, M-P., Baceta, J.I.,
Berggren, W.A., Bernaola, G., Caballero, F., Clemmensen, A., Dinarès-Turell, J.,
Dupuis, C., Heilmann-Clausen, C., Hilario Orús, A., Knox, R., MartÃn-Rubio, M.,
Ortiz, S., Payros, A., Petrizzo M.R., von Salis, K., Sprong, J., Steurbaut, E.,
& Thomsen, E., 2011. The Global Stratotype Sections and Points for the bases of
the Selandian (Middle Paleocene) and Thanetian (Upper Paleocene) stages at
Zumaia Spain. Episodes 34/4, p. 220-243.
