Towards an astronomical-tuned Cenozoic time scale

Author(s): Hilgen, Frits; Lourens, Lucas; Kuiper, Klaudia; Palike, Heiko; Rohl, Ursula; Westerhold, Thomas
Author Affiliation(s): Primary:
Utrecht University, Utrecht, Netherlands
Other:
Vrije Universiteit, Netherlands
University of Southampton, United Kingdom
Bremen University, Federal Republic of Germany
Volume Title: 33rd international geological congress; abstracts
Source: International Geological Congress [International Geological Congress, Abstracts = Congrès Géologique International, Résumés, Vol.33; 33rd international geological congress, Oslo, Norway, Aug. 6-14, 2008. Publisher:], [location varies], International CODEN: IGABBY
Note: In English
Summary: Recent progress demonstrates that an astronomical-tuned Geological Time Scale (AGTS) for the Cenozoic is now within reach. Critical are the development of a new numerical solution for the Solar System accurate over the last 50-60 million years, the recovery of deep-sea successions suitable for tuning and the intercalibration with the 40Ar/39Ar and U/Pb radio-isotopic dating methods, the latter providing tight constraints for the astronomical calibration of pre-Neogene successions. The entire Neogene was tuned in GTS2004 and only underwent minor refinements and modifications during the last years. Significant progress has been made in the tuning of the Paleogene. Pacific ODP Site 1218 with an excellent magnetostratigraphy and calcareous plankton biostratigraphy was used to tune the entire Oligocene, while attempts have also been made to tune the Eocene-Oligocene boundary stratotype section at Massignano. Tuning of the (younger part of the) Eocene remains problematical but will be the subject of, e.g., scheduled IODP Expeditions 317/319 in the Equatorial Pacific. A preliminary tuning of the older part of the Eocene was presented in three papers and included both the Paleocene-Eocene boundary, and the PETM and ELMO hypothermal events. The entire Paleocene was recently tuned and three options with a ∼400-kyr age difference were presented, resulting in ages of 65.28, 65.68, 66.08 Ma for the K/Pg boundary. Although option three is consistent with a revised 40Ar/39Ar age of 65.95 Ma for the boundary using the astronomical age of 28.201 ± 0.023 Ma for the FCT sanidine standard, the key question is whether the full error propagation will allow to constrain the astronomical tuning of the K/Pg boundary on the 400-kyr eccentricity scale. This problem may delay the construction of a full astronomical-tuned time scale for the Paleocene.
Year of Publication: 2008
Research Program: IODP Integrated Ocean Drilling Program
ODP Ocean Drilling Program
Key Words: 12 Stratigraphy, Historical Geology and Paleoecology; Ar-40/Ar-39; Argon; Biostratigraphy; Calibration; Canterbury Basin; Cenozoic; East Pacific; Eocene; Equatorial Pacific; Expedition 317; Expedition 319; Integrated Ocean Drilling Program; Isotope ratios; Isotopes; Leg 199; Magnetostratigraphy; NanTroSEIZE; Noble gases; North Pacific; Northeast Pacific; Northwest Pacific; Numerical models; ODP Site 1218; Ocean Drilling Program; Pacific Ocean; Paleocene; Paleogene; Plankton; Radioactive isotopes; Solar system; South Pacific; Southwest Pacific; Stable isotopes; Stratigraphic boundary; Tertiary; Time scales; U/Pb; West Pacific
Coordinates: N085300 N085300 W1352200 W1352200
Record ID: 2010056358
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