A New Look at the Paleocene/Eocene Thermal Maximum in New Jersey: Dicing and Slicing the Stratigraphic Record
Abstract
We correlated eight onshore sites (Clayton, Wilson Lake, Sea Girt, Ancora, Millville, Double Trouble, Island Beach, and Bass River) in the New Jersey coastal plain spanning the Paleocene/Eocene Thermal Maximum (PETM), using carbon isotopic stratigraphy constrained by nannofossil biostratigraphy. Coastal plain records are correlated to astronomical and He-3 chronologies in deep sea sites, which suggests high coastal plain sedimentation rates (5 to >10 cm/kyr). We recognize 6 PETM intervals from older to younger: 1) a precursor δ13C increase at Wilson Lake and Ancora that occurs within the silts of the Vincentown Formation; 2) the Carbon Isotopic Excursion (CIE) decrease of 5-7 per mil which occurs in at least 1 sharp step (<<10 kyr) and is associated with a change to the kaolinite-smectite-rich Marlboro Clay Member; 3) a longer interval (~20-30 kyr) of decreasing values; 3) a "boxcar" interval of universally low and constant δ13C values that lasted 30-40 kyr; 4) an exponential interval of recovery to δ13C values that were 1-2% lower than pre-CIE values over 40 kyr (He-3) to 65 kyr (astronomical) that marks the top of the Marlboro Clay; and 5) a distinct sequence E0 of the Vincentown Formation whose base appears to be a regional if not global sea level lowering. There is also likely a sequence boundary at or immediately below the precursor δ13C, though the significance of this is unclear. The basal E0 sequence boundary completely truncates the Marlboro Clay (CIE through recovery interval) at Island Beach and Double Trouble, truncates the recovery interval at Sea Girt, Ancora, and Bass River, and partially truncates the recovery at Wilson Lake, which dates the sea-level fall as ~100 kyr younger than the CIE. The CIE to recovery interval thus occurs within one sequence named Eα, and is likely bracketed by regional if not global sea-level falls. The dicing and slicing of the PETM interval is due to erosion associated with the E0 sequence boundary and emphasizes that integrated isotope stratigraphy is necessary to parse out complex stratigraphic relationships.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2011
- Bibcode:
- 2011AGUFMPP22A..04W
- Keywords:
-
- 4930 PALEOCEANOGRAPHY / Greenhouse gases;
- 4948 PALEOCEANOGRAPHY / Paleocene/Eocene thermal maximum