[1] Noble gas data from the Glacial Drift, the shallowest aquifer in southern Michigan confirm findings by Ma et al. (2004) that modern noble gas temperatures (NGTs) are systematically below the current mean annual air temperature (MAAT) which, in turn, is similar to the ground temperature of these recharge waters. By tracking noble gas concentrations as well as stable isotope ratios through an...

We investigated the highest constant temperature at which actinopterygian fishes can complete their lifecycles, based on an oxygen supply model for cleavage-stage eggs. This stage is one of the most heat-sensitive periods during the lifecycle, likely reflecting the exhaustion of maternally supplied heat shock proteins without new production. The model suggests that average eggs would not develo...

Paleoelevation reconstructions derived from proxy data such as stable oxygen isotope records in terrestrial archives have been determined for Cenozoic mountain ranges around the world. Recent studies highlighted that a variety of paleoclimate processes can contribute to isotopic composition measured precipitation (? 18 O p ) signal used elevation reconstructions. These include: regional, global...

Oxygen isotope ratios in bivalve shells have long been used as a proxy for environmental change, reflecting both temperature and the oxygen composition of host water. In estuarine systems, water is complicated by variable mixing between river seawater, well evaporative enrichment. addition, due to species-specific variation temperature-dependent fractionation into carbonate, modern calibrations...

Plant δ13C-temperature (δ-T) relation has been established in many systems and is often used as paleotemperature transfer function. However, it is still unclear about the exact contributions of temperature variation to plant 13C discrimination because of covariation between temperature and precipitation (aridity), which reduces confidence in reconstruction of paleoclimate. In this study, we mea...

Fossil Chironomidae assemblages (with a few Chaoboridae and Ceratopogonidae) from Zagoskin and Burial Lakes in western Alaska provide quantitative reconstructions of mean July air temperatures for periods of the late-middle Wisconsin (w39,000–34,000 cal yr B.P.) to the present. Inferred temperatures are compared with previously analyzed pollen data from each site summarized here by indirect ord...

Mammals dominate modern terrestrial herbivore ecosystems, whereas extant herbivorous reptiles are limited in diversity and body size. The evolution of reptile herbivory and its relationship to mammalian diversification is poorly understood with respect to climate and the roles of predation pressure and competition for food resources. Here, we describe a giant fossil acrodontan lizard recovered ...

The ubiquitous occurrence of glycerol dialkyl glycerol tetraethers (GDGTs) in soils and their ability to record temperature and environmental changes offer the prospect of independently reconstructing continental paleotemperature and paleoenvironment from the loess-paleosol sequences (LPS) from the Chinese Loess Plateau (CLP). In this study we present records of GDGT-derived proxies for the las...

[1] Stable oxygen isotope fractionation factors (a’s) between individual dissolved carbonate species (CO2(aq.), H2CO3, HCO3 , CO3 2 ) and water, and their sum (S = [CO2(aq.)] + [H2CO3] + [HCO3 ] + [CO3 2 ]) and water are fundamental geochemical parameters. While values of a(CO2(aq.) H2O), a(HCO3 H2O), and a(CO32 H2O) have recently been examined, an overall mass balance for stable oxygen isotope...

[1] A conundrum exists regarding whether the sea-surface temperatures decreased or increased over the southern Caribbean and the western Tropical Atlantic region during the Younger Dryas when the North Atlantic cooled substantially and the Atlantic thermohaline circulation was weakened significantly. Despite the proximity of core locations, some proxy reconstructions record a surface cooling, w...