Chronostratigraphic significance of the “Thüringian” palynological record from the Permian of Iberia and the Balearic Islands: Implications for correlations across Western Europe

Abstract

The formation and subsequent fragmentation of Pangea drove significant paleogeographic, paleoclimatic, and paleoenvironmental shifts during the Permian. In order to date and establish the temporal sequence of these changes, palynostratigraphical criteria are frequently employed. However, the continued use of informal regional terms has hindered a consistent chronostratigraphic framework for events of this period. “Autunian” and “Thüringian”, historically proposed in the 19th century to subdivide the Permian based on French stratigraphy, lack formal chronostratigraphic definition and have persisted despite their ambiguity, contributing to ongoing confusion in Permian correlations. While Permian palynology provides valuable biostratigraphic constraints, a thorough reevaluation and alignment with the Global Permian Chronostratigraphic Scale remains necessary. This study contributes to refining the palynostratigraphy of the upper Cisuralian to Lopingian interval in Spain through a critical review and correlation of palynological assemblages traditionally referred to as “Thüringian” from the Iberian Range and the Balearic Islands. New palynological data are also presented for several stratigraphic units. In the Iberian Range, assemblages from the Boniches, Alcotas, Tormón, and Hoz del Gallo formations are examined, with new data from the Boniches and Alcotas formations. In the Balearic Islands, the Pedra de S'Ase Formation and the P3 Unit are evaluated, including new data from the former. The age of these assemblages is interpreted as follows: upper Kungurian to lowermost Wordian for the Boniches and Pedra de S'Ase formations; lower Wordian to Capitanian for the Alcotas Formation; no older than upper Kungurian or (most likely lower Wordian to Capitanian) for the Hoz del Gallo Formation; and upper Wuchiapingian for the P3 Unit. By characterizing the composition and temporal distribution of these palynofloras, and applying consistent methodological criteria, this study supports the correlation of Iberian and Balearic “Thüringian” assemblages with the upper Kungurian to Wuchiapingian interval. These results argue for the formal abandonment of regionally ambiguous terms such as “Thüringian” and “Autunian” in favor of globally recognized stratigraphic nomenclature.