Marine biotic signals across a late Eocene impact layer at Massignano,Italy: evidence for long‐term environmental perturbations? |
| |
| Authors: | R. Coccioni,D. Basso,H. Brinkhuis,S. Galeotti,S. Gardin,S. Monechi,& S. Spezzaferri |
| |
| Affiliation: | Istituto di Geologia e Centro di Palinologia dell'Università, Campus Scientifico, LocalitàCrocicchia, 61209 Urbino, Italy;Dipartimento di Scienze della Terra, Via Mangiagalli 34, 20133 Milano, Italy;Laboratory of Palaeobotany and Palynology, Institute of Palaeoclimate and Palaeoenvironment Utrecht, Utrecht University, Budapestlaan 4, 3584 CD Utrecht, The Netherlands;Istituto di Geologia e Centro di Palinologia dell'Università, Campus Scientifico, LocalitàCrocicchia, 61209 Urbino, Italy;Dipartimento di Scienze della Terra, Via La Pira 4, 50121 Firenze, Italy;Dipartimento di Scienze della Terra, Via La Pira 4, 50121 Firenze, Italy;Geology and Palaeontology Institut, University of Wien, Geo-Zentrum, Althanstrasse 14, Wien, Austria |
| |
| Abstract: | The Eocene–Oligocene transition marks the passage from 'greenhouse' conditions to an 'icehouse' state, with progressive global cooling starting in the early middle Eocene. The late Eocene presents substantial evidence for extraterrestrial impacts whose effects on living organisms and climatic changes are still not completely clear. A high-resolution, microfloral and faunal investigation has been carried out in a 4-m-thick segment of the Massignano Global Stratotype Section and Point for the Eocene–Oligocene boundary. The studied interval includes a late Eocene (35.7 ± 0.4 Myr old) impactoclastic layer containing several cosmic signatures. The impact event recorded at Massignano had no abrupt, dramatic effects on marine biota in terms of extinction. However, significant quantitative changes in the calcareous plankton and dinoflagellate cyst assemblages occurred 60 kyr after the impact event. The observed pattern is intepreted as reflecting a long-term re-organization of water structure. |
| |
| Keywords: | |
|
|
