Contact: Katherine Unger Baillie
University of Pennsylvania
Caption: Jane Willenbring (upper right) takes samples to date a boulder in Spain's Bejar mountain range. Her findings helped show that ancient glaciers in the region reached their maximum size several thousands of years earlier than once believed.
Credit: University of Pennsylvania
Usage Restrictions: Please credit the University of Pennsylvania for this image.
Related news release: Penn study finds earlier peak for Spain's glaciers