The Pignola-Abriola section (southern Apennines, Italy): a new GSSP candidate for the base of the Rhaetian Stage
Articolo
Data di Pubblicazione:
2015
Citazione:
The Pignola-Abriola section (southern Apennines, Italy): a new GSSP candidate for the base of the Rhaetian Stage / M. Rigo, A. Bertinelli, G. Concheri, G. Gattolin, L. Godfrey, M.E. Katz, M. Maron, P. Mietto, G. Muttoni, M. Sprovieri, F. Stellin, M. Zaffani. - In: LETHAIA. - ISSN 0024-1164. - (2015). [Epub ahead of print] [10.1111/let.12145]
Abstract:
The base of the Rhaetian stage (Norian/Rhaetian boundary, NRB) is still awaiting formal designation by the International Commission on Stratigraphy. At present, only the 4.30-m-thick Steinbergkogel section (Austria) has been proposed as GSSP (Global Stratotype Section and Point) candidate for the base of the Rhaetian. Here we present data from the 63-m-thick Pignola-Abriola section (Southern Apennines, Italy) that we consider an alternative candidate for the Rhaetian GSSP. The Pignola-Abriola basinal section, represented by hemipelagic-pelagic carbonate successions belonging to the Lagonegro Basin, matches all the requirements for a GSSP: 1, it is well exposed with minimal structural deformation; 2, it is rich in age diagnostic fossils (e.g. conodonts and radiolarians); 3, it yields a geochemical record suitable for correlation (e.g. δ13Corg/carb ); and 4, it has a robust magnetostratigraphy and is correlated with the Newark APTS for age approximation of the NRB and additional Rhaetian bioevents. In the Pignola-Abriola section, we opt to place the NRB at the 44.4 metre level, coincident with a prominent negative shift of ca. 6‰ of the δ13Corg . This level is located 50 cm below the FAD of conodont Misikella posthernsteini s.s within the radiolarian Proparvicingula moniliformis Zone. Both the negative δ13Corg shift and the FAD of Misikella posthernsteini occur within Pignola-Abriola magnetozone MPA-5r, at ~205.7 Ma, according to magnetostratigraphical correlation to the Newark APTS. We also illustrate the coeval Mt. Volturino stratigraphical section deposited below the calcite compensation depth (CCD) within the same Lagonegro Basin and characterized by a detailed radiolarian biostratigraphy and strong δ13Corg negative shift around the NRB.
Tipologia IRIS:
01 - Articolo su periodico
Keywords:
Conodonts; GSSP; Late Triassic; Magnetostratigraphy; Radiolarians; Rhaetian; Stable isotopes
Elenco autori:
M. Rigo, A. Bertinelli, G. Concheri, G. Gattolin, L. Godfrey, M.E. Katz, M. Maron, P. Mietto, G. Muttoni, M. Sprovieri, F. Stellin, M. Zaffani
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