GSSP for Thanetian Stage (Paleocene)

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 2.8 m 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 43º 17′ 58.4″N, and a longitude of 02º 15′ 39.1″W. The GSSP for the Thanetian is about 78 m above the Cretaceous/ Paleogene boundary.

Sedimentology:

The lower part of the Itzurun Formation can be subdivided into a lower, ca. 24 m thick Member A and an upper, 52 m thick Member B. The boundary between the two members is 6.5 m 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. 1 m thick interval recording a drastic decrease in CaCO3. This clay is interpreted as the Mid-Paleocene Biotic Event.

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., Martín-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, 220-243.