Iron X-ray fluorescence (XRF) scannings of ODP Holes 165-1001A and 171-1050C ...
Abstract: Ocean Drilling Program Sites 1001A (Caribbean Sea) and 1050C (western North Atlantic) display obliquity and precession cycles throughout polarity zone C27 of the late Danian stage (earliest Cenozoic time). Sliding-window spectra analysis and direct cycle counting on downhole logs and high-...
Main Authors: | , , , |
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Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
PANGAEA
2001
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Subjects: | |
Online Access: | https://dx.doi.org/10.1594/pangaea.774793 https://doi.pangaea.de/10.1594/PANGAEA.774793 |
Summary: | Abstract: Ocean Drilling Program Sites 1001A (Caribbean Sea) and 1050C (western North Atlantic) display obliquity and precession cycles throughout polarity zone C27 of the late Danian stage (earliest Cenozoic time). Sliding-window spectra analysis and direct cycle counting on downhole logs and high-resolution Fe variations at both sites yield the equivalent of 35-36 obliquity cycles. This cycle-tuned duration for polarity chron C27 of 1.45 Ma (applying a modern mean obliquity period of 40.4 ka) is consistent with trends from astronomical tuning of early Danian polarity chron C29 and 40Ar/39Ar age calibration of the Campanian-Maastrichtian magnetic polarity time scale. The cycle-tuned Danian stage (sensu Berggren et al. 1995, in SEPM Special Publications, 54, 129-212) spans 3.65 Ma (65.5-61.85 Ma). Spreading rates on a reference South Atlantic synthetic profile display progressive slowing during the Maastrichtian to Danian stages, then remained relatively constant through late Palaeocene and early Eocene time. ... : Supplement to: Röhl, Ursula; Ogg, James G; Geib, Tricia L; Wefer, Gerold (2001): Astronomical calibration of the Danian time scale. In: Norris, R D, Kroon, D, & Klaus, A (eds.), Western North Atlantic Palaeogene and Cretaceous Palaeoceanography. Geological Society, London, Special Publication, 183, 163-183 ... |
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