Around 40,000 years ago, Paleolithic humans on the Korean Peninsula began to make small and sharp stone blades. Stone blades were produced by repeatedly detaching long, flat flakes from a core of fine-grained stone, such as hornfels, shale or tuff. The blades were then further processed into small, delicate stone tools. Tanged-points were affixed to spears and used for hunting. This type of tool was first made on the Korean Peninsula and its production technology spread to neighboring regions with the movement of populations. They have also been found in Kyushu, Japan.