Magnetochronology of the Entire Chinle Formation (Norian Age) in a Scientific Drill Core From Petrified Forest National Park (Arizona, USA) and Implications for Regional and Global Correlations in the Late Triassic
AuthorKent, Dennis V.
Olsen, Paul E.
Gehrels, George E.
Irmis, Randall B.
Geissman, John W.
Parker, William G.
AffiliationUniv Arizona, Dept Geosci
MetadataShow full item record
PublisherAMER GEOPHYSICAL UNION
CitationKent, D. V., Olsen, P. E., Lepre, C., Rasmussen, C., Mundil, R., Gehrels, G. E., et al (2019). Magnetochronology of the entire Chinle Formation (Norian age) in a scientific drill core from Petrified Forest National Park (Arizona, USA) and implications for regional and global correlations in the Late Triassic. Geochemistry, Geophysics, Geosystems, 20. https://doi.org/10.1029/ 2019GC008474
Rights© 2019. American Geophysical Union. All Rights Reserved.
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AbstractBuilding on an earlier study that confirmed the stability of the 405-kyr eccentricity climate cycle and the timing of the Newark-Hartford astrochronostratigraphic polarity time scale back to 215 Ma, we extend the magnetochronology of the Late Triassic Chinle Formation to its basal unconformity in scientific drill core PFNP-1A from Petrified Forest National Park (Arizona, USA). The 335-m-thick Chinle section is imprinted with paleomagnetic polarity zones PF1r to PF10n, which we correlate to chrons E17r to E9n (209 to 224 Ma) of the Newark-Hartford astrochronostratigraphic polarity time scale. A sediment accumulation rate of 34 m/Myr can be extended down to 270 m, close to the base of the Sonsela Member and the base of magnetozone PF5n, which we correlate to chron E14n that onsets at 216.16 Ma. Magnetozones PF5r to PF10n in the underlying 65-m-thick section of the mudstone-dominated Blue Mesa and Mesa Redondo members plausibly correlate to chrons E13r to E9n, indicating a sediment accumulation rate of only 10 m/Myr. Published high-precision U-Pb detrital zircon dates from the lower Chinle tend to be several million years older than the magnetochronological age model. The source of this discrepancy is unclear but may be due to sporadic introduction of juvenile zircons that get recycled. The new magnetochronological constraint on the base of the Sonsela Member brings the apparent timing of the included Adamanian-Revueltian land vertebrate faunal zone boundary and the Zone II to Zone III palynofloral transition closer to the temporal range of the 215 Ma Manicouagan impact structure in Canada.
Note6 month embargo; first published: 16 October 2019
VersionFinal published version
SponsorsNSF National Science Foundation (NSF) [EAR 0958976, 0958723, 0958915, 0959107, 0958859, EAR-1338583]; Deutsche ForschungsgemeinschaftGerman Research Foundation (DFG); Lamont-Climate Center; Ann and Gordon Getty Foundation