The scientists studied the history of glaciers in the Tailan River valley in China. They used a method called electron spin resonance dating to figure out when different moraines were formed. They found that the oldest glacial deposits in the area are from a time called the "Kokdepsang Glacial Stage", which happened a long time ago. The researchers also discovered that the glaciers in the valley have changed a lot over time, with different moraines being deposited during different periods of cold climate. The findings suggest that the valley had compound valley glaciers during the Little Ice Age and marine isotope stages 2-4, and piedmont glaciers during marine isotope stage 6.