FRANKFURT. Corals and cave carbonates are important archives of past climate. This is because the composition of these carbonate deposits can reveal the temperatures that prevailed at the Earth’s surface at the time they formed. An international team of geoscientists led by Goethe University Frankfurt, Germany, has now developed a new method that makes it possible to identify whether the composition of these deposits was exclusively controlled by temperature, or if the formation process itself exerted an additional control. The new method allows scientists to determine past Earth surface temperatures more reliably.