Telltale Rock (IMAGE) Columbia Climate School Caption In Baffin Island's Naqsaq Valley, University at Buffalo geologist Jason Briner samples a boulder left by a glacier around the time of early Viking settlement. Measurements of chemical isotopes within the rock suggest settlers in neighboring Greenland faced cold weather. Credit Nicolás Young Usage Restrictions Credit must be given. 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.