CALCAREOUS NANNOFOSSILS AT THE TRIASSIC/JURASSIC BOUNDARY: STRATIGRAPHIC AND PALEOCEANOGRAPHIC CHARACTERIZATION
In this work, calcareous nannofossils are identified for the first time in the uppermost Triassic sequence of the Lombardy Basin (Southern Calcareous Alps, Italy). Two zones are recognized, namely the NT2b (latest Triassic) and the NJT1 (earliest Jurassic). Two species resulted to be good markers to...
Main Authors: | , , , , , |
---|---|
Format: | Text |
Language: | English |
Published: |
Università degli Studi di Milano
2016
|
Subjects: | |
Online Access: | https://dx.doi.org/10.13130/2039-4942/7726 http://riviste.unimi.it/index.php/RIPS/article/view/7726 |
id |
ftdatacite:10.13130/2039-4942/7726 |
---|---|
record_format |
openpolar |
spelling |
ftdatacite:10.13130/2039-4942/7726 2023-05-15T17:51:46+02:00 CALCAREOUS NANNOFOSSILS AT THE TRIASSIC/JURASSIC BOUNDARY: STRATIGRAPHIC AND PALEOCEANOGRAPHIC CHARACTERIZATION BOTTINI, CINZIA JADOUL, FLAVIO RIGO, MANUEL ZAFFANI, MARIACHIARA ARTONI, CLAUDIO ERBA, ELISABETTA 2016 https://dx.doi.org/10.13130/2039-4942/7726 http://riviste.unimi.it/index.php/RIPS/article/view/7726 en eng Università degli Studi di Milano This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License. http://creativecommons.org/licenses/by-nc-nd/4.0 CC-BY-NC-ND Calcareous nannofossils; Triassic/Jurassic boundary; stable isotopes; Lombardy Basin. Text Article article-journal ScholarlyArticle 2016 ftdatacite https://doi.org/10.13130/2039-4942/7726 2021-11-05T12:55:41Z In this work, calcareous nannofossils are identified for the first time in the uppermost Triassic sequence of the Lombardy Basin (Southern Calcareous Alps, Italy). Two zones are recognized, namely the NT2b (latest Triassic) and the NJT1 (earliest Jurassic). Two species resulted to be good markers to constrain the TJB interval: Prinsiosphaera triassica and Schizosphaerella punctulata. Nannofossil data are calibrated with C isotopic chemostratigraphy obtained for carbonate and organic matter. Size reduction of P. triassica and a decline in the abundance of Triassic nannofossils are detected soon after the “precursor Carbon Isotope Excursion (CIE) and culminated during the “initial negative CIE” characterized by lowest nannofossil abundances and small-sized P. triassica. The extinction of Triassic nannofossils occurred in distinctive steps within the “initial negative CIE”, while the Jurassic S. punctulata is first observed at the base of the “main negative CIE”. The latest Triassic nannofossil decline in abundance, size reduction and extinctions, represent a progressive deterioration associated to the Central Atlantic Magmatic Province (CAMP) volcanism. Our findings are consistent with nannofossil changes at supraregional scale and indicate that the massive CAMP flood basalts were preceded by initial volcanic pulses. We speculate that a combination of climate change, fertilization and ocean acidification started to influence the calcification process prior to the “initial negative CIE”. Nannoplankton extinctions were not simultaneous and might imply limited capacity for adaptation in the early stages of evolutionary history. However, originations of new taxa soon after the disappearance of Triassic forms suggest the ability to rapidly overcame extreme stressing conditions. : Rivista Italiana di Paleontologia e Stratigrafia (Research In Paleontology and Stratigraphy), Vol 122, No 3 (2016) Text Ocean acidification DataCite Metadata Store (German National Library of Science and Technology) |
institution |
Open Polar |
collection |
DataCite Metadata Store (German National Library of Science and Technology) |
op_collection_id |
ftdatacite |
language |
English |
topic |
Calcareous nannofossils; Triassic/Jurassic boundary; stable isotopes; Lombardy Basin. |
spellingShingle |
Calcareous nannofossils; Triassic/Jurassic boundary; stable isotopes; Lombardy Basin. BOTTINI, CINZIA JADOUL, FLAVIO RIGO, MANUEL ZAFFANI, MARIACHIARA ARTONI, CLAUDIO ERBA, ELISABETTA CALCAREOUS NANNOFOSSILS AT THE TRIASSIC/JURASSIC BOUNDARY: STRATIGRAPHIC AND PALEOCEANOGRAPHIC CHARACTERIZATION |
topic_facet |
Calcareous nannofossils; Triassic/Jurassic boundary; stable isotopes; Lombardy Basin. |
description |
In this work, calcareous nannofossils are identified for the first time in the uppermost Triassic sequence of the Lombardy Basin (Southern Calcareous Alps, Italy). Two zones are recognized, namely the NT2b (latest Triassic) and the NJT1 (earliest Jurassic). Two species resulted to be good markers to constrain the TJB interval: Prinsiosphaera triassica and Schizosphaerella punctulata. Nannofossil data are calibrated with C isotopic chemostratigraphy obtained for carbonate and organic matter. Size reduction of P. triassica and a decline in the abundance of Triassic nannofossils are detected soon after the “precursor Carbon Isotope Excursion (CIE) and culminated during the “initial negative CIE” characterized by lowest nannofossil abundances and small-sized P. triassica. The extinction of Triassic nannofossils occurred in distinctive steps within the “initial negative CIE”, while the Jurassic S. punctulata is first observed at the base of the “main negative CIE”. The latest Triassic nannofossil decline in abundance, size reduction and extinctions, represent a progressive deterioration associated to the Central Atlantic Magmatic Province (CAMP) volcanism. Our findings are consistent with nannofossil changes at supraregional scale and indicate that the massive CAMP flood basalts were preceded by initial volcanic pulses. We speculate that a combination of climate change, fertilization and ocean acidification started to influence the calcification process prior to the “initial negative CIE”. Nannoplankton extinctions were not simultaneous and might imply limited capacity for adaptation in the early stages of evolutionary history. However, originations of new taxa soon after the disappearance of Triassic forms suggest the ability to rapidly overcame extreme stressing conditions. : Rivista Italiana di Paleontologia e Stratigrafia (Research In Paleontology and Stratigraphy), Vol 122, No 3 (2016) |
format |
Text |
author |
BOTTINI, CINZIA JADOUL, FLAVIO RIGO, MANUEL ZAFFANI, MARIACHIARA ARTONI, CLAUDIO ERBA, ELISABETTA |
author_facet |
BOTTINI, CINZIA JADOUL, FLAVIO RIGO, MANUEL ZAFFANI, MARIACHIARA ARTONI, CLAUDIO ERBA, ELISABETTA |
author_sort |
BOTTINI, CINZIA |
title |
CALCAREOUS NANNOFOSSILS AT THE TRIASSIC/JURASSIC BOUNDARY: STRATIGRAPHIC AND PALEOCEANOGRAPHIC CHARACTERIZATION |
title_short |
CALCAREOUS NANNOFOSSILS AT THE TRIASSIC/JURASSIC BOUNDARY: STRATIGRAPHIC AND PALEOCEANOGRAPHIC CHARACTERIZATION |
title_full |
CALCAREOUS NANNOFOSSILS AT THE TRIASSIC/JURASSIC BOUNDARY: STRATIGRAPHIC AND PALEOCEANOGRAPHIC CHARACTERIZATION |
title_fullStr |
CALCAREOUS NANNOFOSSILS AT THE TRIASSIC/JURASSIC BOUNDARY: STRATIGRAPHIC AND PALEOCEANOGRAPHIC CHARACTERIZATION |
title_full_unstemmed |
CALCAREOUS NANNOFOSSILS AT THE TRIASSIC/JURASSIC BOUNDARY: STRATIGRAPHIC AND PALEOCEANOGRAPHIC CHARACTERIZATION |
title_sort |
calcareous nannofossils at the triassic/jurassic boundary: stratigraphic and paleoceanographic characterization |
publisher |
Università degli Studi di Milano |
publishDate |
2016 |
url |
https://dx.doi.org/10.13130/2039-4942/7726 http://riviste.unimi.it/index.php/RIPS/article/view/7726 |
genre |
Ocean acidification |
genre_facet |
Ocean acidification |
op_rights |
This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License. http://creativecommons.org/licenses/by-nc-nd/4.0 |
op_rightsnorm |
CC-BY-NC-ND |
op_doi |
https://doi.org/10.13130/2039-4942/7726 |
_version_ |
1766159017197961216 |