Middle–Upper Jurassic stable isotope records and seawater temperature variations: New palaeoclimate data from marine carbonate and belemnite rostra (Pieniny Klippen Belt, Carpathians)

First steps in reconstructing Early Jurassic sea water temperatures in the Andean Basin of northern Chile based on stable isotope analyses of oyster and brachiopod shells

“…Following a phase of very low temperatures during the Late Pliensbachian, increased volcanic activity in the Early Toarcian in combination with other factors (such as the release of methane hydrates from continental shelfs; Hesselbo et al 2000a) seems to have caused perturbations in the carbon cycle, intense global warming, ocean acidification, and ultimately mass extinctions (e.g., Aberhan and Fürsich 1996;Pálfy and Smith 2000;Aberhan and Baumiller 2003;Cecca and Macchioni 2004;Gómez et al 2008;Dera et al 2010;Dera and Donnadieu 2012;Danise et al 2013;Huang and Hesselbo 2014;Krencker et al 2014). While the global nature of many of the Early Jurassic events (particularly the TOAE) has been illustrated by geochemical analyses of rocks outside Europe (e.g., Al-Suwaidi et al 2010, 2016Mazzini et al 2010;Caruthers et al 2011;Gröcke et al 2011;Suan et al 2011;Yi et al 2013;Kemp and Izumi 2014;Ros-Franch et al 2019), reconstructions of absolute water temperatures for the Early Jurassic are almost completely restricted to the northwestern Tethys. In the present study, a collection of Sinemurian to Toarcian oyster and brachiopod shells from the Andean Basin of Chile has been analyzed for their stable isotope (δ 13 C, δ 18 O) content in a first step to remedy this lack of data.…”

Palaeoceanographic regime during the Oxfordian–Kimmeridgian in the Western Tethys recorded by radiolarian assemblages in the siliceous sediments of the Pieniny Klippen Belt, Carpathians

“…If this occurred during the Jurassic, westerly winds would have intensified along the equator, causing upwelling in the Western Tethys that induced a rise in the thermocline in this region, including the Pieniny Basin. The prevailing upwelling regime in this area with a shallowing thermocline is confirmed by the increased diversity of radiolarian taxa, fluctuations in the thermocline surface radiolarian index, and sea surface temperature changes, all recorded using oxygen stable isotope data (Arabas, ; Figure ). The temperature gradient across the tropical and subtropical Tethys Ocean during this time was expressed by the cooler‐than‐normal superficial water in its western part (the Western Tethys region).…”

“…Thus, such conditions might cause weakening of westerly winds along the equator, allowing warm water to shift west towards the north‐western Tethys that would have induced formation of the warm stratified superficial water in that region. The increase in water temperature during the late Kimmeridgian is confirmed by oxygen stable isotope composition from cephalopods of the nektobenthic mode of life, found in the Pieniny Klippen Belt (Arabas, ; Wierzbowski, ). A repeated increase in intermediate radiolarian groups, a decrease in radiolarian diversity (Figure ), and a decreasing trend in the TSRI values during this interval are confirmation of the decreasing upwelling frequency and the formation of prolonged warm and strong stratified surface waters in the western part of the Tethys, including the area studied.…”

“…Distribution of three radiolarian ecological groups along the middle Oxfordian–upper Kimmeridgian sediments of the Czajakowa section, Niedzica succession, Pieniny Klippen Belt, Carpathians, in relation to total radiolarian abundance, species diversity (Simpson: 1‐D), thermocline surface radiolarian index, and temperature of intermediate water (Arabas, ) with variations of thermocline depth [Colour figure can be viewed at wileyonlinelibrary.com]…”

Integrated biostratigraphy and carbon isotope stratigraphy of the Upper Jurassic shallow water carbonates of the High-Tatric Unit (Mały Giewont area, Western Tatra Mountains, Poland)

“…The de creas ing trend of d 13 C within the KimmeridgianTithonian is a well-known phe nom e non (e.g., Cecca et al, 2001;Padden et al, 2002;Weissert and Erba, 2004;Jach et al, 2014;Arabas, 2016;Price et al, 2016). The over all sim i larity of the d 13 C de creas ing val ues re corded in the Kimmeridgian-low er most Tithonian in ter val of the Ma³y Giewont area (this study) and the D³uga Val ley sec tions indi cates that the gen er ally shal low-wa ter lime stones of the RTL Fm ac cu mu lated be low the zone in flu enced by changes in the com po si tion of ma rine wa ter caused, for in stance, by in tense rain fall.…”