Improving techniques and interpretations for reconstructing high-resolution paleoclimate in deep time from bivalve shells and tooth enamel

Reconstructions of climate in the past teach us about climate variability during various periods in Earth’s history. While many paleoclimate studies have focused on the climate reconstructions over long timescales (thousands to millions of years), the effect of climate change on short-term (years to decades) variability must be better understood to improve our models for future climate change. Such high-resolution climate data can be obtained from a range of archives such as ice cores, tree rings and corals. These archives have allowed researchers to reconstruct high-resolution climate change over the past few thousand years. However, in order to obtain a more complete understanding of climate variability during more extreme climates, we need to look at climate variability millions of years in the past (in deep time). Such reconstructions require climate archives that preserve their original chemical variability on a seasonal or even daily scale over these long timescales. The shells of bivalves and the enamel of fossil teeth are promising candidates for this purpose. The research presented in this thesis takes a critical look at the potential of teeth and shells for preserving their original chemical composition in the fossil record, and how chemical proxies measured in these archives can be used to reconstruct climate.