Original paper
An orbitally paced, near-complete record of Campanian climate and sedimentation in the Mississippi Embayment, USA
O’Connor, Lauren K.; Batenburg, Sietske J.; Robinson, Stuart A.; Jenkyns, Hugh C.
Newsletters on Stratigraphy Volume 53 Number 4 (2020), p. 443 - 459
published: Sep 17, 2020
published online: Mar 16, 2020
manuscript accepted: Nov 28, 2019
manuscript revision received: Nov 28, 2019
manuscript revision requested: Feb 6, 2019
manuscript received: Dec 21, 2018
ArtNo. ESP026005304003, Price: 29.00 €
Abstract
The Campanian Stage (84.2–72.1 Ma) marked the transition from the ‘hot greenhouse’ of the mid-Cretaceous to the ‘cool greenhouse’ of the Maastrichtian. Despite being the longest stage of the Late Cretaceous, the Campanian is poorly understood climatically and represents a “gap” in the astronomically tuned time scale. Few marine records are described outside of Europe, and only a limited portion of the sediments preserved show an imprint of orbitally driven changes in insolation. Independent age constraints are limited, and the seeming absence of major, transient climatic events in the Campanian hampers correlation. Here we present a lithological and elemental record from the Shuqualak–Evans Borehole (Mississippi, USA), which intersects a sequence of hemipelagic marlstones and chalks deposited at ~35° N. This core exhibits prominent lithological rhythmicity (alternations of marly chalk and marlstone, recognised in CaCO3 content) reflecting variations in land–sea interaction in the Gulf Coast region. The ~10 Myr-long record of Campanian climate reveals a hierarchy of cycles, corresponding to the periodicities of eccentricity-modulated precession, and with a pervasive imprint of obliquity forcing. The new cyclostratigraphic framework is in good agreement with GTS ages for available δ13C data and biostratigraphic divisions. Re-interpreted carbon-isotope excursions in the Shuqualak record correspond well with events identified and dated in the European chalk sections, including the Campanian–Maastrichtian Boundary Event, the Late Campanian Event, and the Mid-Campanian Event. The new age model developed in this study confirms that the Shuqualak core encompasses almost the entire Campanian and may represent the most complete record of this time interval outside Europe, thereby offering a unique window into the climate dynamics of the period.
Keywords
Campanian • orbital forcing • astrochronology • palaeoclimate • land–ocean interaction • integrated stratigraphy