Tempo and duration of short-term environmental perturbations across the Cretaceous-Paleogene boundary

Author(s): Husson, Dorothée; Galbrun, Bruno; Gardin, Silvia; Thibault, Nicolas R.
Author Affiliation(s): Primary:
Technological Institute, Department of Earth and Planetary Sciences, Evanston, IL, United States
Universités Pierre et Marie Curie-Paris VI-Sorbonne, France
University of Copenhagen, Denmark
Volume Title: Stratigraphy
Source: Stratigraphy, 11(2), p.159-171. Publisher: Micropaleontology Press, New York, NY, United States. ISSN: 1547-139X
Note: In English. 131 refs.; illus., incl. strat. cols., 3 tables, sketch map
Summary: The complex interplay between extraterrestrial events and earth-bound processes that triggered one of the greatest biological crises of the Phanerozoic requires a high resolution timescale. Detailed magnetic susceptibility measurements at the Contessa Highway and Bottaccione sections (Italy) span the Cretaceous-Paleogene boundary and reveal clear orbital signatures in the sedimentary record. Identification of precession and 405 kyr eccentricity cycles allows an estimate of 324±40 kyr for the duration of the Maastrichtian part of Chron C29r. We present in the same high resolution time frame sites in Spain and the North and South Atlantic and bio-horizons, biotic changes, stable isotopic excursions and the decrease in Osmium isotopes recorded in these sections. The onset of 187Os/188Os decrease coincides with the ?C negative excursion K-PgE1, thus suggesting a first pulse in Deccan volcanism at 66.64 Ma. The K-PgE3 δ13C negative excursion is possibly the expression of a second pulse at 66.26 Ma. Late Maastrichtian δ13C negative excursions are of low intensity and span durations of one to two eccentricity cycles, whereas early Danian excursions are brief (about 30 kyr) and acute. Biotic response to late Maastrichtian perturbations occurred with a delay of ca. 200 kyr after the beginning of K-PgE1 shortly before K-PgE3. The biotic perturbation could be thus either a delayed response to K-PgE1, or a direct response to K-PgE3, and possibly, a threshold response to the stepwise buildup of CO2 atmospheric injections. No delay is evident in response to early Danian hyperthermal events. These differences suggest that short-lived, volcanically-derived environmental perturbations were buffered within the stable late Maastrichtian oceanic realm whereas they were amplified by the more sensitive and highly disturbed early Danian oceanic ecosystem.
Year of Publication: 2014
Research Program: ODP Ocean Drilling Program
Key Words: 12 Stratigraphy, Historical Geology and Paleoecology; Apennines; Atlantic Ocean; Bottaccione Gorge; C-13/C-12; Carbon; Cenozoic; Climate forcing; Contessa Valley; Correlation; Cretaceous; Cyclostratigraphy; Europe; Isotope ratios; Isotopes; Italy; K-T boundary; Leg 208; Lower Paleocene; Maestrichtian; Magnetic properties; Magnetic susceptibility; Mesozoic; Metals; ODP Site 1267; Ocean Drilling Program; Orbital forcing; Os-188/Os-187; Osmium; Paleocene; Paleoclimatology; Paleoenvironment; Paleogene; Paleomagnetism; Platinum group; Scaglia Rossa; South Atlantic; Southern Europe; Stable isotopes; Stratigraphic boundary; Tertiary; Umbria Italy; Upper Cretaceous; Walvis Ridge
Coordinates: N422000 N434000 E0131500 E0115000
S280600 S280600 E0014300 E0014200
Record ID: 2015028609
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute.