Environmental perturbations at the early Eocene ETM2, H2, and I1 events as inferred by Tethyan calcareous plankton (Terche section, northeastern Italy)

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doi: 10.1002/2016PA002940
Author(s): D'Onofrio, Roberta; Luciani, Valeria; Fornaciari, Eliana; Giusberti, Luca; Boscolo Galazzo, Flavia; Dallanave, Edoardo; Westerhold, Thomas; Sprovieri, Mario; Telch, Sonia
Author Affiliation(s): Primary:
Universita di Ferrara, Dipartimento di Fisica e Scienze della Terra, Ferrara, Italy
Other:
Universita di Padova, Italy
Ludwig Maximilians University of Munich, Germany
University of Bremen, Germany
CNR, Istituto per l'Ambiente Marino Costiero, Italy
Volume Title: Paleoceanography
Source: Paleoceanography, 31(9), p.1225-1247. Publisher: American Geophysical Union, Washington, DC, United States. ISSN: 0883-8305 CODEN: POCGEP
Note: In English. 148 refs.; illus., incl. strat. col., 2 tables, sketch map
Summary: Several early Eocene hyperthermals have been recently investigated and characterized in terms of temperature anomalies and oceanographic changes. The effects of these climatic perturbations on biotic communities are much less constrained. Here we present new records from the Terche section (northeastern Italy) that, for the first time, integrates data on planktic foraminifera and calcareous nannofossils across three post-Paleocene-Eocene Thermal Maximum negative carbon isotope excursions (CIEs). The biomagnetostratigraphic framework generated at Terche allows us to confidently relate such CIEs to the Eocene Thermal Maximum 2 (ETM2), H2, and I1 events. Each of these events coincides with lithological anomalies characterized by significantly lower calcium carbonate content (marly units, MUs). We interpret these MUs as mainly linked to an effect of increased terrigenous dilution, as dissolution proxies do not display significant variations. Calcareous plankton assemblages change significantly across these events and radiolarians increase. Observed changes suggest that transient warming and environmental perturbations, though more intense during ETM2, occurred during each of the three investigated perturbations. Variations among calcareous plankton suggest increase in surface-water eutrophication with respect to the pre-event conditions, coupled with a weakening of the upper water-column thermal stratification. Higher nutrient discharge was related to intensification of the hydrological cycle as a consequence of the warmer climate. These conditions persisted during the early CIE recovery, implying slower recovery rates for the environment and biota than for the carbon cycle. Abstract Copyright (2016), . American Geophysical Union. All Rights Reserved.
Year of Publication: 2016
Research Program: ODP Ocean Drilling Program
Key Words: 02 Geochemistry; 12 Stratigraphy, Historical Geology and Paleoecology; Algae; Assemblages; Atlantic Ocean; Belluno Italy; Biostratigraphy; Biozones; C-13/C-12; Calcium carbonate; Carbon; Cenozoic; Chemostratigraphy; Correlation; Demerara Rise; Eocene; Equatorial Atlantic; Europe; Foraminifera; Invertebrata; Isotope ratios; Isotopes; Italy; Leg 207; Leg 208; Lithostratigraphy; Lower Eocene; Magnetostratigraphy; Marine environment; Mel Italy; Microfossils; Nannofossils; North Atlantic; Northwest Atlantic; O-18/O-16; ODP Site 1258; ODP Site 1262; Ocean Drilling Program; Oxygen; Paleo-oceanography; Paleobathymetry; Paleoenvironment; Paleogene; Plantae; Preservation; Protista; Radiolaria; South Atlantic; Southern Europe; Stable isotopes; Terche Creek; Tertiary; Tethys; Veneto Italy; Walvis Ridge; West Atlantic
Coordinates: S271100 S271100 E0013500 E0013400
N092600 N092600 W0544400 W0544400
N460300 N460300 E0120500 E0120500
Record ID: 2016094463
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from John Wiley & Sons, Chichester, United Kingdom