 |
| Titel |
Orbitally tuned timescale and astronomical forcing in the middle Eocene to early Oligocene |
| VerfasserIn |
T. Westerhold, U. Röhl, H. Pälike, R. Wilkens, P. A. Wilson, G. Acton |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1814-9324
|
| Digitales Dokument |
URL |
| Erschienen |
In: Climate of the Past ; 10, no. 3 ; Nr. 10, no. 3 (2014-05-16), S.955-973 |
| Datensatznummer |
250116972
|
| Publikation (Nr.) |
 copernicus.org/cp-10-955-2014.pdf |
|
|
|
|
|
| Zusammenfassung |
| Deciphering the driving mechanisms of Earth system processes, including the
climate dynamics expressed as paleoceanographic events, requires a complete,
continuous, and high-resolution stratigraphy that is very accurately dated.
In this study, a robust astronomically calibrated age model was constructed
for the middle Eocene to early Oligocene interval (31–43 Ma) in
order to permit more detailed study of the exceptional climatic events that
occurred during this time, including the middle Eocene climate optimum and
the Eocene–Oligocene transition. A goal of this effort is to accurately date
the middle Eocene to early Oligocene composite section cored during the
Pacific Equatorial Age Transect (PEAT, IODP Exp. 320/321). The stratigraphic
framework for the new timescale is based on the identification of the stable
long eccentricity cycle in published and new high-resolution records
encompassing bulk and benthic stable isotope, calibrated XRF core scanning,
and magnetostratigraphic data from ODP Sites 171B-1052, 189-1172, 199-1218,
and 207-1260 as well as IODP Sites 320-U1333, and 320-U1334 spanning magnetic
polarity Chrons C12n to C20n. Subsequently orbital tuning of the records to
the La2011 orbital solution was conducted. The resulting new timescale
revises and refines the existing orbitally tuned age model and the
geomagnetic polarity timescale from 31 to 43 Ma. The newly defined
absolute age for the Eocene–Oligocene boundary validates the astronomical
tuned age of 33.89 Ma identified at the Massignano, Italy, global
stratotype section and point. The compilation of geochemical records of
climate-controlled variability in sedimentation through the middle-to-late
Eocene and early Oligocene demonstrates strong power in the eccentricity band
that is readily tuned to the latest astronomical solution. Obliquity driven
cyclicity is only apparent during 2.4 myr eccentricity cycle minima
around 35.5, 38.3, and 40.1 Ma. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|