Figure 3

Reconstructed Early Maastrichtian temperature and seawater δ¹⁸O for the Cauvery Basin. (A) δ¹⁸O of Phygraea vesicularis shell 1 measured by dual inlet IRMS (squares) and shell 2 (diamonds) measured by continuous flow IRMS (1 mm resolution). Shell 2 was also analysed by SHRIMP with a 25 µm spot size and 150 µm spacing (circles). (B) Seasonal temperatures for shell 1 reconstructed using clumped isotope thermometry (CDES scale). (C) Calculated δ¹⁸O of water using IRMS shell δ¹⁸Odata in (A, B) and the empirical δ¹⁸O-temperature relationship for molluscan calcite of Dettman et al., 1999 (ref.¹²). Tan shading indicates cooler/wetter winter seasons.