Description: 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, 3º00’51.61″ 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 maximum flooding 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.

Location: 167.85 metres in the Gorrondatxe sea-cliff section (NW of Bilbao city, Basque Country, northern Spain. The latitude and longitude of the section are 43º22’46.47″ N, 3º00’51.61″ W respectively.

Sedimentology: Dark Marl.

Primary Markers: Lowest Occurrence (LO) of calcareous nannofossil Blackites inflatus (CP12a/b boundary); middle of polarity Chron C21r.

Reference:

Molina E., Alegret L., Apellaniz E., et al. (2011). The Global Stratotype Section and Point (GSSP) for the base of the Lutetian Stage at the Gorrondatxe section, Spain. Episodes 34, 86-108.