CALCAREOUS NANNOFOSSIL BIOSTRATIGRAPHY AND PALEOCEANOGRAPHY OF THE TOARCIAN OCEANIC ANOXIC EVENT AT COLLE DI SOGNO (SOUTHERN ALPS, NORTHERN ITALY)
We present calcareous nannofossil biostratigraphy and abundances for the Upper Pliensbachian-Lower Toarcian interval, including the Toarcian Oceanic Anoxic Event (T-OAE), represented by the Fish Level at Colle di Sogno (N Italy). In addition to biohorizons identifying NJT 5 and NJT 6 nannofossil zon...
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Milano University Press
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ftunivmilriv:oai:ojs.riviste.unimi.it:article/6520 2023-12-31T10:21:38+01:00 CALCAREOUS NANNOFOSSIL BIOSTRATIGRAPHY AND PALEOCEANOGRAPHY OF THE TOARCIAN OCEANIC ANOXIC EVENT AT COLLE DI SOGNO (SOUTHERN ALPS, NORTHERN ITALY) CASELLATO, CRISTINA EMANUELA ERBA, ELISABETTA 2015-11-19 application/pdf https://riviste.unimi.it/index.php/RIPS/article/view/6520 https://doi.org/10.13130/2039-4942/6520 eng eng Milano University Press https://riviste.unimi.it/index.php/RIPS/article/view/6520/6550 https://riviste.unimi.it/index.php/RIPS/article/view/6520 doi:10.13130/2039-4942/6520 Copyright (c) 2015 Rivista italiana di Paleontologia e Stratigrafia RIVISTA ITALIANA DI PALEONTOLOGIA E STRATIGRAFIA Vol. 121 No. 3 (2015) Rivista italiana di Paleontologia e Stratigrafia; V. 121 N. 3 (2015) 2039-4942 0035-6883 calcareous nannofossils biostratigraphy paleoecology paleoceanography Pliensbachian/Toarcian boundary interval Toarcian Oceanic Anoxic Event info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion 2015 ftunivmilriv https://doi.org/10.13130/2039-4942/6520 2023-12-05T23:14:07Z We present calcareous nannofossil biostratigraphy and abundances for the Upper Pliensbachian-Lower Toarcian interval, including the Toarcian Oceanic Anoxic Event (T-OAE), represented by the Fish Level at Colle di Sogno (N Italy). In addition to biohorizons identifying NJT 5 and NJT 6 nannofossil zones, the first occurrences of C. superbus and D. striatus constrain the onset and the end of the T-OAE, respectively. We propose the last occurrence of M. jansae as additional event to approximate the end of the T-OAE at lower latitudes. Quantitative data highlight the “Schizosphaerella decline” marking the Pliensbachian/Toarcian boundary and the “Schizosphaerella crisis” at the onset of the T-OAE as supplementary biohorizons. S. punctulata and M. jansae constitute most of the micrite in the interval below the Fish Level, which is marked by an increase in abundance of small coccoliths remaining abundant in the overlying interval, with limited contributions of S. punctulata, while M. jansae disappears. Principal Component Analysis implemented nannofossil paleoecological and paleoenvironmental reconstructions. The latest Pliensbachian was characterized by stable oligotrophic conditions favourable to calcification at low pCO2 levels promoting the proliferation of deep-dwelling and highly-calcified S. punctulata. During the earliest Toarcian an initial pulse of continental run-off introduced terrigenous material favouring the intermediate-dweller M. jansae and the low-salinity adapted Calyculus. Higher nutrient concentrations and ocean acidification magnified during the T-OAE, stimulatying mesotrophic low-calcified coccolith-producers and suppressing k-strategist deep- to intermediate-dwellers. After the T-OAE, partial recovery of calcareous nannoplankton indicates still perturbed conditions. Ecosystem modifications anticipated the T-OAE of ~1 million years with species origination and major changes in assemblages. Article in Journal/Newspaper Ocean acidification University of Milan: Riviste UNIMI |
institution |
Open Polar |
collection |
University of Milan: Riviste UNIMI |
op_collection_id |
ftunivmilriv |
language |
English |
topic |
calcareous nannofossils biostratigraphy paleoecology paleoceanography Pliensbachian/Toarcian boundary interval Toarcian Oceanic Anoxic Event |
spellingShingle |
calcareous nannofossils biostratigraphy paleoecology paleoceanography Pliensbachian/Toarcian boundary interval Toarcian Oceanic Anoxic Event CASELLATO, CRISTINA EMANUELA ERBA, ELISABETTA CALCAREOUS NANNOFOSSIL BIOSTRATIGRAPHY AND PALEOCEANOGRAPHY OF THE TOARCIAN OCEANIC ANOXIC EVENT AT COLLE DI SOGNO (SOUTHERN ALPS, NORTHERN ITALY) |
topic_facet |
calcareous nannofossils biostratigraphy paleoecology paleoceanography Pliensbachian/Toarcian boundary interval Toarcian Oceanic Anoxic Event |
description |
We present calcareous nannofossil biostratigraphy and abundances for the Upper Pliensbachian-Lower Toarcian interval, including the Toarcian Oceanic Anoxic Event (T-OAE), represented by the Fish Level at Colle di Sogno (N Italy). In addition to biohorizons identifying NJT 5 and NJT 6 nannofossil zones, the first occurrences of C. superbus and D. striatus constrain the onset and the end of the T-OAE, respectively. We propose the last occurrence of M. jansae as additional event to approximate the end of the T-OAE at lower latitudes. Quantitative data highlight the “Schizosphaerella decline” marking the Pliensbachian/Toarcian boundary and the “Schizosphaerella crisis” at the onset of the T-OAE as supplementary biohorizons. S. punctulata and M. jansae constitute most of the micrite in the interval below the Fish Level, which is marked by an increase in abundance of small coccoliths remaining abundant in the overlying interval, with limited contributions of S. punctulata, while M. jansae disappears. Principal Component Analysis implemented nannofossil paleoecological and paleoenvironmental reconstructions. The latest Pliensbachian was characterized by stable oligotrophic conditions favourable to calcification at low pCO2 levels promoting the proliferation of deep-dwelling and highly-calcified S. punctulata. During the earliest Toarcian an initial pulse of continental run-off introduced terrigenous material favouring the intermediate-dweller M. jansae and the low-salinity adapted Calyculus. Higher nutrient concentrations and ocean acidification magnified during the T-OAE, stimulatying mesotrophic low-calcified coccolith-producers and suppressing k-strategist deep- to intermediate-dwellers. After the T-OAE, partial recovery of calcareous nannoplankton indicates still perturbed conditions. Ecosystem modifications anticipated the T-OAE of ~1 million years with species origination and major changes in assemblages. |
format |
Article in Journal/Newspaper |
author |
CASELLATO, CRISTINA EMANUELA ERBA, ELISABETTA |
author_facet |
CASELLATO, CRISTINA EMANUELA ERBA, ELISABETTA |
author_sort |
CASELLATO, CRISTINA EMANUELA |
title |
CALCAREOUS NANNOFOSSIL BIOSTRATIGRAPHY AND PALEOCEANOGRAPHY OF THE TOARCIAN OCEANIC ANOXIC EVENT AT COLLE DI SOGNO (SOUTHERN ALPS, NORTHERN ITALY) |
title_short |
CALCAREOUS NANNOFOSSIL BIOSTRATIGRAPHY AND PALEOCEANOGRAPHY OF THE TOARCIAN OCEANIC ANOXIC EVENT AT COLLE DI SOGNO (SOUTHERN ALPS, NORTHERN ITALY) |
title_full |
CALCAREOUS NANNOFOSSIL BIOSTRATIGRAPHY AND PALEOCEANOGRAPHY OF THE TOARCIAN OCEANIC ANOXIC EVENT AT COLLE DI SOGNO (SOUTHERN ALPS, NORTHERN ITALY) |
title_fullStr |
CALCAREOUS NANNOFOSSIL BIOSTRATIGRAPHY AND PALEOCEANOGRAPHY OF THE TOARCIAN OCEANIC ANOXIC EVENT AT COLLE DI SOGNO (SOUTHERN ALPS, NORTHERN ITALY) |
title_full_unstemmed |
CALCAREOUS NANNOFOSSIL BIOSTRATIGRAPHY AND PALEOCEANOGRAPHY OF THE TOARCIAN OCEANIC ANOXIC EVENT AT COLLE DI SOGNO (SOUTHERN ALPS, NORTHERN ITALY) |
title_sort |
calcareous nannofossil biostratigraphy and paleoceanography of the toarcian oceanic anoxic event at colle di sogno (southern alps, northern italy) |
publisher |
Milano University Press |
publishDate |
2015 |
url |
https://riviste.unimi.it/index.php/RIPS/article/view/6520 https://doi.org/10.13130/2039-4942/6520 |
genre |
Ocean acidification |
genre_facet |
Ocean acidification |
op_source |
RIVISTA ITALIANA DI PALEONTOLOGIA E STRATIGRAFIA Vol. 121 No. 3 (2015) Rivista italiana di Paleontologia e Stratigrafia; V. 121 N. 3 (2015) 2039-4942 0035-6883 |
op_relation |
https://riviste.unimi.it/index.php/RIPS/article/view/6520/6550 https://riviste.unimi.it/index.php/RIPS/article/view/6520 doi:10.13130/2039-4942/6520 |
op_rights |
Copyright (c) 2015 Rivista italiana di Paleontologia e Stratigrafia |
op_doi |
https://doi.org/10.13130/2039-4942/6520 |
_version_ |
1786832509871325184 |