Palaeogene climate evolution in the Paris Basin from oxygen stable isotope (δ ¹⁸ O) compositions of marine molluscs

Abstract

The constraint of temperature evolution in coastal environments is an important factor in deciphering the Earth's global climatic history. In this study, we reconstruct the evolution of sea-surface palaeotemperatures from the oxygen stable isotope compositions in four marine molluscs families in the Paris Basin during the Palaeogene. The combination of several taxa living in different environments is used to limit uncertainties related to the influence of salinity variations on palaeotemperature estimations. One family of bivalves (oysters) and three families of gastropods (Volutidae, Cerithiidae and Turritellidae) were sampled in the French part of the Paris Basin, in Belgium and in the Isle of Wight (southern England). Maximum seawater temperatures were observed during the Early Eocene (c. 30°C), which correspond to the Early Eocene Climatic Optimum, and temperatures then decreased until the Lutetian (c. 20°C). A transient warming, identified as the Middle Eocene Climatic Optimum, occurred during the Bartonian, when temperatures reached 32°C. Temperatures decreased through the Eocene-Oligocene boundary, the coolest interval of the Palaeogene (c. 12°C). A final warming period occurred throughout the Early Oligocene, with temperatures reaching 24°C. The fossils analysed thus record the global climatic intervals of the Palaeogene.

Seasonality fluctuations recorded in fossil bivalves during the early Pleistocene: Implications for climate change

“…These species have been shown to lack vital effects which make them suitable for stable isotope analyses and seasonal paleotemperature reconstructions (e.g., Hickson et al, 1999;Schöne et al, 2005;Brocas et al, 2013;Royer et al, 2013;Schöne, 2013;Bušelić et al, 2015). Shallow-water mollusks represent an accurate archive of paleoclimatic information, and have been successfully used for past climate reconstructions (e.g., Ivany et al 2008;Huyghe et al, 2015), even if they can be influenced by salinity changes that affect δ 18 O and thus the estimated paleotemperatures (Huyghe et al, 2015). To accurately interpret the data resulting from the isotope analyses it is thus important to take into account also the paleoecology of the studied species, focusing especially on those variables which can affect the isotope signals and their consequent interpretation, such as the living depth and the tolerance to salinity changes.…”

Differentiation of high‐latitude and polar marine faunas in a greenhouse world

“…The Antarctic and two tropical localities all show clear indications that the richness of Early Cenozoic neogastropods peaked during the Middle Eocene (Crame et al, 2014;Dockery & Lozouet, 2003;Huyghe, Lartaud, Emmanuel, Merle, & Renard, 2015; Supporting Information Figures S1-S3). Nevertheless, levels of dissimilarity between all three localities in the Palaeocene are already extremely high, as there are no genera in common between the Paris Basin (42 genera) and Antarctica (19 genera), and only one between the U.S. Gulf Coast (45 genera) and Antarctica (Table 1; Appendix).…”

“…The Calcaire Grossier Formation (CGF) outcrops more or less in the centre of the Paris Basin, where it has a total thickness in the Huyghe et al, 2015). Owing to the intermittent nature of the exposures and highly variable lithologies, establishment of a standard stratigraphy for the CGF has proved problematic, but it has now been strengthened by the provision of two neostratotypes (Merle, 2008a).…”

“…The taxonomic framework used for neogastropods is explained below. A variety of palaeoclimatic indicators suggest that subtropical to tropical climates predominated in the Paris Basin from the Late Maastrichtian to Middle Eocene (Huyghe et al, 2012(Huyghe et al, , 2015Merle, 2008b).…”

“…Grossier Formation (CGF) outcrops more or less in the centre of the Paris Basin, where it has a total thickness in the region of 40-50 m. It ranges in age from the upper part of the Lower Lutetian into well within the Upper Lutetian; the highly fossiliferous intervals are all Middle Lutetian in age (De Wever & Corn ee, 2008; G ely, 2008; Huyghe, Merle, Lartaud, Cheype, & Emmanuel, 2012;Huyghe et al, 2015). Owing to the intermittent nature of the exposures and highly variable lithologies, establishment of a standard stratigraphy for the CGF has proved problematic, but it has now been strengthened by the provision of two neostratotypes(Merle, 2008a).The base of the CGF proper is marked by the 2-m-thick 'Couche de la Pierre a liards', which comprises calcareous glauconitic sands with Nummulites laevigatus (G ely, 2008).…”