Late Triassic to Early Jurassic radiolarian, conodont and ammonite assemblages from the Tavuscayiri block, Mersin Mélange, southern Turkey: Time constraints for the T/J boundary and sedimentary evolution of the southern margin of the northern Neotethys

Abstract

Late Triassic to Early Jurassic radiolarian, conodont and ammonite assemblages from the Tavuscayiri block, Mersin Mélange, southern Turkey: Time constraints for the T/J boundary and sedimentary evolution of the southern margin of the northern Neotethys.

Lower Jurassic conodonts from the Inuyama area of Japan: implications for conodont extinction

“…However, the certainty of the Jurassic age of the conodonts N. detrei has always been controversial. First, the age of radiolarian C. merum is not considered exclusively Jurassic, Tekin et al (2020) presents a range of Rhaetian to lower Sinemurian for this radiolarian in southern Turkey. Second, poor preservation hinders firm identification of ammonoids (Pálfy et al, 2007).…”

Integrated Stratigraphy (Radiolarians, Calcareous Nannofossils, Carbon and Strontium Isotopes) of the Sinemurian–Pliensbachian Transition at Mt. Rettenstein, Northern Calcareous Alps, Austria

“…Crepidolithus pliensbachensis 2010), but has been reported from Pliensbachian samples in other localities (Goričan et al, 2006;Tekin et al, 2020). Samples Rö448 and Rö453, taken from the upper part of the section, yielded several taxa that first appear in the Canutus tipperi -Katroma clara Zone.…”

“…Potentially important are some less well documented species that so far have not been found above the Sinemurian. These include Katroma hocakoeyensis Tekin, documented only from the Sinemurian of the Antalya Nappes in Turkey (Tekin, 2002), Paurinella liassica Tekin, known only in the Sinemurian (Tekin et al, 2020), Liassobetraccium spp., ranging from the Hettangian to the Sinemurian (O'Dogherty et al, 2009), Palaeosaturnalis parvus (Kozur and Mostler, 1990), recorded in the Hettangian type locality only (Kozur and Mostler, 1990) and Ares rettensteinensis Cifer, originally assigned to the Lower Pliensbachian (Cifer et al, 2020) but should probably be corrected to the Upper Sinemurian. Canoptum hettangicum (Kozur and Mostler, 1990) identified in sample Rö438 is the only welldocumented species for which the reported last occurrence does not reach the Upper Sinemurian.…”

“…It is noteworthy that none of the sections included in the construction of these zones contain a continuous record of Late Sinemurian to Early Pliensbachian radiolarian assemblages. Among subsequently described radiolarian sections, only the Orbuklukeli section in the Mersin Mélange, Turkey, includes Sinemurian and earliest Pliensbachian assemblages (Tekin et al, 2020) but the preservation across the boundary is very variable and poor in most samples.…”