The GSSP for the base of the Lutetian Stage (early/
middle Eocene boundary) is defined at 167.85 metres in
the Gorrondatxe sea-cliff section (NW of Bilbao city,
Basque Country, northern Spain; 43º22'46.47" N, 3º 00'
51.61" W). This dark marly level coincides with the lowest
occurrence of the calcareous nannofossil Blackites
inflatus (CP12a/b boundary), is in the middle of polarity
Chron C21r, and has been interpreted as the maximumflooding
surface of a depositional sequence that may be
global in extent. The GSSP age is approximately 800 kyr
(39 precession cycles) younger than the beginning of
polarity Chron C21r, or ~47.8 Ma in the GTS04 time
scale. The proposal was approved by the International
Subcommission on Paleogene Stratigraphy in February
2010, approved by the International Commission of
Stratigraphy in January 2011, and ratified by the International
Union of Geological Sciences in April 2011.Published86-1082.2. Laboratorio di paleomagnetismoJCR Journalrestricte
