Early Danian paleotemperature records from Neuquén Basin-Argentina: Applications of the ostracod Sr/Ca paleothermometer

作者：Marlone H.H. Bom, Karlos G.D. Kochhann, Rodrigo do Monte Guerra, Daiane Ceolín, Guilherme Krahl, Luciana R.C. Duarte, Mírian L.A.F. Pacheco, Thorsten Bauersachs, Luiz Frederico Rodrigues, Flávia Callefo, Franciele Agnesa Trentin, Douglas Galante, Telma Musso, Lorenz Schwark, Andrea Concheyro, Gerson Fauth · 发表于：Evolving Earth · 年份：2026 · DOI：10.1016/j.eve.2026.100113 · 被引用次数：1 · 研究领域：Geology and Paleoclimatology Research、Geological and Geochemical Analysis、Paleontology and Stratigraphy of Fossils

The early Danian is marked by a recovery in marine and terrestrial ecosystems after the Cretaceous-Paleogene mass extinction. Both sea surface temperature (SST) and bottom water temperature (BWT) reconstructions are essential for a better understanding of paleoclimatic developments occurring at this critical time interval. Paleotemperature reconstructions based on ostracods are an excellent alternative for studies in regions where benthic foraminifera are scarce or absent. In this context, we present a paleotemperature reconstruction of the Cerro Azul Section, Neuquén Basin, Argentina, based on the ostracod Henryhowella (Wichmannella) meridionalis (Bertels, 1974). Trace element/calcium ratios (El/Ca) were determined on well preserved specimens using two different analytical techniques: (i) oxidative cleaning followed by acid digestion (measured with ICP OES), and (ii) laser ablation (measured with LA-ICP-MS). Our results show that El/Ca ratios of ornamented species are more effectively quantified using acid digestion. Although some intervals show high values of the Al/Ca ratio, which could suggest the presence of remaining clay and/or organic contaminants. Low values of both Fe/Ca and Mn/Ca ratios indicate efficient cleaning regarding oxyhydroxides. As the incorporation of Mg and Sr into inorganic calcite is a thermodynamic process, we mapped the distribution of both trace elements on ostracod valves in nanoscale using Synchrotron-based X-ray fluorescence (nannoXRF). Our resu...