Publication Date:
2021-05-17
Description:
At least two transient events of extreme global warming occurred superimposed on the long-term latest
Paleocene and early Eocene warming trend in the Paleocene-Eocene thermal maximum (PETM) (or ETM1
~55.5 Ma) and the Elmo (or ETM2 ~53.6 Ma). Other than warmth, the best known PETM is characterized by
(1) significant injection of 13C-depleted carbon into the ocean-atmosphere system, (2) deep-sea carbonate
dissolution, (3) strong biotic responses, and (4) perturbations of the hydrological cycle. Documentation of the
other documented and suspected "hyperthermals" is, as yet, insufficient to assess whether they are similar in
nature to the PETM. Here we present and discuss biomagnetostratigraphic data and geochemical records across
two lower Eocene successions deposited on a continental margin of the western Tethys: the Farra and Possagno
sections in the Venetian pre-Alps. We recognize four negative carbon isotope excursions within chron C24.
Three of these shifts correlate to known or suspected hyperthermals: the PETM, the Eocene thermal maximum 2
(~53.6 Ma), and the informally named "X event" (~52.5 Ma). The fourth excursion lies within a reverse
subchron and occurred between the latter two. In the Farra section, the X event is marked by a ~0.6% negative
carbon isotope excursion and carbonate dissolution. Furthermore, the event exhibits responses among calcareous
nannofossils, planktic foraminifera, and dinoflagellates that are similar to, though less intense than, those
observed across the PETM. Sedimentological and quantitative micropaleontological data from the Farra section
also suggest increased weathering and runoff as well as sea surface eutrophication during this event.
Description:
Published
Description:
PA2209
Description:
2.2. Laboratorio di paleomagnetismo
Description:
JCR Journal
Description:
reserved
Keywords:
Paleoclimate
;
Hyperthermal events
;
Early Eocene
;
Bio-magnetostratigraphy
;
Geochemistry
;
04. Solid Earth::04.04. Geology::04.04.10. Stratigraphy
;
04. Solid Earth::04.05. Geomagnetism::04.05.06. Paleomagnetism
;
04. Solid Earth::04.05. Geomagnetism::04.05.09. Environmental magnetism
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
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