A Slice through a Tropical Stalagmite (IMAGE) California Institute of Technology Caption A slice through a stalagmite from a cave in northern Borneo reveals the gradual growth of the calcite structure. By measuring the ratio of oxygen isotopes in such samples, Caltech's Adkins and his colleagues were able to reconstruct a history of the climate in the tropics throughout the late Pleistocene era. Credit Adkins/Caltech Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.