A detailed magnetostratigraphic investiga-\ud tion of the Pignola-Abriola section of Norian\ud to Rhaetian age permits the identification of\ud 22 magnetic polarity reversals grouped in 10\ud magnetozones. We correlate the magneto-\ud stratigraphy of the Pignola-Abriola section\ud with the Newark astrochronological polarity\ud time scale (APTS). In total, 19 correlation\ud options were tested, and only one (option 7)\ud yielded a statistically significant correlation\ud that was consistent with the available infor-\ud mation on the stratigraphic age of the Newark\ud APTS. After some adjustments to minimize\ud erratic variations in sediment accumulation\ud rates, a final correlation (option 7.1) was used\ud to generate an age model of sedimentation\ud for the Pignola-Abriola section. The Pignola-\ud Abriola section has been correlated with\ud Rhaetian sections from the literature, notably\ud the current global boundary stratotype sec-\ud tion and point candidate for the base of the\ud Rhaetian at Steinbergkogel, Austria, where\ud the Norian-Rhaetian boundary is proposed\ud to be placed at a stratigraphic level contain-\ud ing the first appearance datum (FAD) of\ud conodont Misikella posthernsteini, traced on\ud the Newark APTS to ca. 209–210 Ma. Issues\ud regarding the taxonomy of M. posthernsteini,\ud a species characterized by transitional forms\ud with its ancestor Misikella hernsteini, lead us\ud to propose the alternative option of placing the\ud Norian-Rhaetian boundary at a prominent\ud negative δ13C spike observed in the Pignola- org\ud Abriola section at meter 44.5, 50 cm below the level containing the FAD of M. posthernsteini sensu stricto and close to the base of radiolarian Proparvicingula moniliformis zone. This level has been magnetostratigraphically cor- related to Newark magnetozone E20r.2r at ca. 205.7 Ma. Assuming an age of ca. 201.3 Ma for the Triassic-Jurassic boundary, the Rhaetian Stage would have a duration of ~4.4 m.y

A global carbon-isotope curve for the Late Triassic has the potential for global correlations and new insights on the complex and extreme environmental changes that took place in this time interval. We reconstruct the global δ 13 C org profile for the late Norian, improving on sparse published data from North American successions that depict a "chaotic carbon-isotope interval" with rapid oscillations. In this context, we studied three sections outcropping in the Lagonegro Basin (southern Italy), originally located in the western Tethys. The carbon-isotope profiles show four negative excursions correlatable within the Lagonegro Basin. In particular, a negative shift close to the Norian/Rhaetian boundary (NRB) appears to correlate with that observed in the North American δ 13 C org record, documenting the widespread occurrence of this carbon cycle perturbation. The 87 Sr/ 86 Sr and 187 Os/ 188 Os profiles suggest that this negative shift was possibly caused by emplacement of a large igneous province (LIP). The release of greenhouse gases (CO 2) to the atmosphere-ocean system is supported by the 12 C enrichment observed, as well as by the increase of atmospheric pCO 2 inferred by different models for the Norian/Rhaetian interval. The trigger of this strongly perturbed interval could thus be enhanced magmatic activity that could be ascribed to the Angayucham province (Alaska, North America), a large oceanic plateau active ca. 214 ± 7 Ma, which has an estimated volume comparable to the Wrangellia and the Central Atlantic Magmatic Province (CAMP) LIPs. In fact, these three Late Triassic igneous provinces may have caused extreme environmental and climate changes during the Late Triassic.

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The base of the Rhaetian stage (Norian/Rhaetian boundary, NRB) is still awaiting for- mal 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. d13Corg/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, coinci- dent with a prominent negative shift of ca. 6& of the d13Corg. This level is located 50 cm below the FAD of conodont Misikella posthernsteini s.s within the radiolarian Proparvicingula moniliformis Zone. Both the negative d13Corg 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 cal- cite compensation depth (CCD) within the same Lagonegro Basin and characterized by a detailed radiolarian biostratigraphy and strong d13Corg negative shift around the NRB