Typology and cross dating
The proto-Inca cultures of South America continued at a Stone Age level until around 2000 BCE, when gold, copper and silver made their entrance, the rest following later.
Australia remained in the Stone Age until the 17th century. In Europe and North America, millstones were in use until well into the 20th century, and still are in many parts of the world.
Much of this study takes place in the laboratory in the presence of various specialists.
In experimental archaeology, researchers attempt to create replica tools, to understand how they were made.
The species who made the Pliocene tools remains unknown.The first evidence of human metallurgy dates to between the 5th and 6th millennium BCE in the archaeological sites of Majdanpek, Yarmovac and Pločnik ( a copper axe from 5500 BCE belonging to the Vincha culture), though not conventionally considered part of the Chalcolithic or "Copper Age", this provides the earliest known example of copper metallurgy. Ötzi the Iceman, a mummy from about 3300 BCE carried with him a copper axe and a flint knife.In regions such as Subsaharan Africa, the Stone Age was followed directly by the Iron Age.Rogers and Semaw, excavators at the locality, point out that: "..earliest stone tool makers were skilled flintknappers ....The possible reasons behind this seeming abrupt transition from the absence of stone tools to the presence thereof include ...