They reached that conclusion based on their studies of pollen that they had retrieved by taking core samples from alluvial deposits (silt, sand, clay, and gravel left by a river or streams in antiquity) located near the site. These pollen samples suggested that there had been a change in vegetation, and that “drier climatic conditions occurred in the Mediterranean belt of Syria from the late 13th/early 12th centuries BC to the 9th century BC.”78
