Naslov
A COMPARISON OF THE NORTH AMERICAN AND EUROPEAN CARNIAN AND NORIAN PALYNOFLORAS
(A COMPARISON OF THE NORTH AMERICAN AND EUROPEAN CARNIAN AND NORIAN PALYNOFLORAS)

Autori
Baranyi, Viktoria ; Kurschner, Wolfram M

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Abstract Book / - Dublin, 2018, 224-224

Skup
10th European Palaeobotany and Palynology Conference

Mjesto i datum
Dublin, Irska, 12.08.2018. - 17.08.2018

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
palynology, Triassic, Europe, North America, stratigraphy

Sažetak
A significant floral turnover recorded in the middle of the Chinle Formation (SW North America) in western equatorial Pangea was previously linked to the termination of the Carnian Pluvial Episode, a wet climate phase in the middle Carnian, and a return to drier climate as seen in Europe in the Tuvalian. Many age-diagnostic species from the European Carnian e.g., Camerosporites secatus, Duplicisporites, Lagenella martinii and Brodispora striata which have their last occurrence in the Tuvalian in Europe, are still present in the lower Chinle Formation which formed the basis for the Carnian-Norian age assignment of the Chinle. However, new magnetostratigraphy and radiometric dating suggested middle to late Norian age. The “final” disappearance of the European taxa is now linked to a gradual shift towards drier climate known as the Mid Norian Climate Shift in SW Pangea due to the northward migration of the North American continent and the uplift of the Cordilleran Arc. Recently, Perinopollenites elatoides has been observed in the middle part of the Chinle. So far, it is the only species with an occurrence in agreement with the European range of the species with first appearance date in the mid Norian. Further difference is the scarcity of the Circumpolles in the Norian palynofloras of the Chinle. The group, especially Classopollis is predominant in European Norian assemblages, but they are uncommon in North America until the Rhaetian. The differences between North American and European palynofloras are mainly manifested in the diachronous stratigraphical ranges of the index taxa which track primarily environmental variations and not biostratigraphical events (Lindström et al. 2016). The heterogeneity of Late Triassic macro- and palynofloras of the Northern Hemisphere is the consequence of the various climate and environments (e.g., topography) on Pangea. This difference between palynofloras may be the result of the generally hot and semi-arid climate in the inner part of Pangea and western Tethyan realm, while a seasonally more humid tropical belt in the SW Pangea perhaps provided a favourbale habitat for the parent plants of the “typical Carnian” taxa until the mid Norian.

Izvorni jezik
Engleski

Znanstvena područja
Geologija

POVEZANOST RADA