Speleothems, such as stalagmites or flowstones, are very valuable terrestrial climate archives because they can be precisely dated, and may contain continuous information about past climate variability on seasonal to multi-millennial timescales.

Stable isotopes of oxygen are most commonly used to reconstruct past rainfall amount or changes in the moisture trajectories from the speleothem records, but also carbon isotopes and trace metals contribute to the steadily growing speleothem proxy tool box.

In this talk, I present new applications of our ongoing work with trace metals and stable isotopes in speleothems in the research group “Physics of Environmental Archives”.

For example, Mg/Ca ratios and stable isotopes can be used as indicators of past drought frequency, as shown in a case study of an early Holocene stalagmite from Mexico. In addition, transition metal ratios (Cu/Ni, Cu/Co) in cave drip waters and speleothems are explored as potential proxies for past tropical cyclone activity.