First record of calpionellids in the Antarctic PeninsulaNew insights on Jurassic and Cretaceous trans-domain correlations

Abstract

The correlation between the Austral domain and the Tethys have been problematic for years due to the high endemism of ammonites and other fossil index groups. Particularly during the Jurassic/Cretaceous transition, microfossils play a unique role, with calpionellids as the gold standard for its determination. Nonetheless, studies of calpionellid focus on the Tethyan domain and have recently been found in the Neuquen Basin (Argentina), opening a new window for the correlation of the Jurassic and Cretaceous sequences. During the Summerfield Argentinian Antarctic Campaign 2022-2023 in Longing Gap, Antarctic Peninsula, detailed work was conducted in the Ameghino (=Nordenskjöld) Formation with several stratigraphic profiles along the nunatak. As a preliminary result, we found the first record of calpionellids in Antarctica, represented by Tintinnopsella carpathica, closely associated with the nannofossil Polycostella beckmannii. This finding sheds new light on the correlation between the Austral and Tethyan domains and the dispersion routes of calpionellid during the Thithonian and Berriassin times. Work in progress includes studying several stratigraphic sections to establish an integrated calpionellid-calcareous nannofossils biostratigraphy and its correlation with other fossil groups.