Constraints from clumped isotope analyses of a stalagmite on maximum tropical temperature change through the late Pleistocene

We analyzed modern and ancient speleothems from caves in Northern Borneo (4°N, 115°W) for their carbonate isotopologue, or 'clumped isotope', compositions. Although this method of paleothermometry appears to exhibit a common calibration in a variety of carbonates, speleothems have so far proven to be difficult archives for this technique. Most samples measured to date are out of equilibrium, yielding apparent temperatures that are too high [1,2].