Publikationsdatum:
2017-04-04
Beschreibung:
An integrated bio-, magneto- and cyclostratigraphic study of the Ypresian/Lutetian
(Early/Middle Eocene) transition along the Otsakar section resulted in the identification of the
C22n/C21r chron boundary and of the calcareous nannofossil CP12a/b zonal boundary; the latter
is the main correlation criterion of the Lutetian Global Stratotype Section and Point (GSSP) recently
defined at Gorrondatxe (Basque Country). By counting precession-related mudstone–marl couplets of
21 ka, the time lapse between both events was calculated to be 819 ka. This suggests that the age of the
CP12a/b boundary, and hence that of the Early/Middle Eocene boundary, is 47.76 Ma, 250 ka younger
than previously thought. This age agrees with, and is supported by, estimates from Gorrondatxe based
on the time lapse between the Lutetian GSSP and the C21r/C21n boundary. The duration of Chron
C21r is estimated at 1.326 Ma. Given that the base of the Eocene is dated at 55.8 Ma, the duration of
the Early Eocene is 8 Ma, 0.8 Ma longer than in current time scales. The Otsakar results further show
that the bases of planktonic foraminiferal zones E8 and P10 are younger than the CP12a/b boundary.
The first occurrence of Turborotalia frontosa, being approximately 550 ka older that the CP12a/b
boundary, is the planktonic foraminiferal event that lies closest to the Early/Middle Eocene boundary.
The larger foraminiferal SBZ12/13 boundary is located close to the CP12a/b boundary and correlates
with Chron C21r, not with the C22n/C21r boundary.
Beschreibung:
In press
Beschreibung:
1-19
Beschreibung:
2.2. Laboratorio di paleomagnetismo
Beschreibung:
JCR Journal
Beschreibung:
restricted
Schlagwort(e):
Eocene
;
Ypresian–Lutetian boundary
;
biostratigraphy
;
magnetostratigraphy
;
cyclostratigraphy
;
04. Solid Earth::04.04. Geology::04.04.08. Sediments: dating, processes, transport
;
04. Solid Earth::04.04. Geology::04.04.10. Stratigraphy
;
04. Solid Earth::04.05. Geomagnetism::04.05.06. Paleomagnetism
Repository-Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Materialart:
article
Permalink