Publikationsdatum:
2017-04-04
Beschreibung:
The astronomical time scale for the Paleocene is hampered
by some uncertainties including discrepant number of 405-kyr
eccentricity related cycles and correlation schemes among key
records being proposed by different authors (Westerhold et al.,
2008; Kuiper et al., 2008; Hilgen et al., 2010). Here we present
a new Danian correlation framework resolved at the ~100-kyr
short-eccentricity level between the land-based Zumaia and
Sopelana hemipelagic sections from the Basque Basin and
deep-sea records drilled during ODP Legs 198 (Shatsky Rise,
North Pacific) and 208 (Walvis Ridge, South Atlantic) that
reconciles both the magnetostratigraphy and the short and longeccentricity
cycle patterns among the records and, hence,
improves synchroneity of events. The correlation has been
aided by composite images from ODP cores and a new wholerock
13C isotope record at Zumaia while its original
magnetostratigraphy (Dinarès-Turell et al., 2003; 2010) is
reinforced by new data from Sopelana. Notably, we challenge
the correlation of the Pacific Sites 1209–1210 that were offset
by as much as one 405-kyr cycle in previous interpretations
(i.e., the Fasciculithus spp. LO, which approximates the
Danian–Selandian (D–S) boundary, and the “Top chron C27n”
climatic event were at odds between oceans in the
interpretation of Hilgen et al. (2010). It is found that the
Danian consists of 11 (and not 10) consecutive 405-kyr
eccentricity cycles.
The new consistent stratigraphic framework enables
accurate estimates to be made of ages for magnetostratigraphic
boundaries, bioevents, and sedimentation rates. Low
sedimentation rates appear common in all records in the mid-
Danian interval along the upper part of chron C28n, including
conspicuous condensed intervals in some of the oceanic
records that in the past have hampered the proper identification
of cycles. The new chronological framework, spanning a
duration of about 4.5 My, allows assessing the role of orbital
forcing on the paleoclimatic variability as registered by the
related isotope records. It appears clear that there exists a
periodic beat at the 100-ky and 405-ky eccentricity cycles
impressed in the record. The phase relationship between the
benthic isotope record and eccentricity is similar to patterns
documented for the Oligocene and Miocene, as indicated by
others, confirming the role of orbital forcing as the pace maker
for paleoclimatic variability on Milankovitch time scales. The
preferred tuning to the La2011 orbital solution provides
astronomically calibrated ages of 66.022±0.040 Ma and
61.607±0.040 Ma for the (D–S) and Cretaceous–Paleogene
(K–Pg) boundaries respectively. Finally, we envisage that the
Zumaia section, which already hosts the Selandian GSSP,
could serve as the global Danian stratotype.
Beschreibung:
Published
Beschreibung:
64-65
Beschreibung:
1A. Geomagnetismo e Paleomagnetismo
Beschreibung:
N/A or not JCR
Beschreibung:
restricted
Schlagwort(e):
cyclostratigraphy
;
magnetostratigraphy
;
ODP
;
orbital tuning
;
03. Hydrosphere::03.01. General::03.01.06. Paleoceanography and paleoclimatology
;
04. Solid Earth::04.04. Geology::04.04.08. Sediments: dating, processes, transport
;
04. Solid Earth::04.04. Geology::04.04.10. Stratigraphy
Repository-Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Materialart:
article
Permalink
