The discovery of a stone flake that shows evidence of being hammered by a hard tool has led scientists to conclude that early humans occupied parts of western Turkey much earlier than previously thought.
In research published this week in Quaternary Science Reviews, the research team suggest that by being able to fix an age for the deposits of an ancient meander of the Gediz river where the flake was found, they can give an accurate, securely-dated timeframe for when early humans occupied the area.
The international research team, involving scientists from the UK, Turkey and the Netherlands, and led by Professor Darrel Maddy at Newcastle University, used high-precision radioisotopic dating and palaeomagnetic measurements from lava flows which both pre-date and post-date the meander loop to establish that early humans were present in the area between approximately 1.24 million and 1.17 million years ago.
These secure age estimates confirm for the first time an earlier date range for hominin occupation of western Anatolia - often suggested as the most likely route for the spread of early humans into Europe.
Although Palaeolithic stone tools have been found in western Turkey before, few have been associated with geological deposits of known age. As a result, the timing of early humans’ progress across the Anatolian peninsula is poorly understood.
The fragment that was found (pictured) is composed mainly of quartz and is approximately five centimetres long. The oldest hominin fossils in western Anatolia were recovered in 2007 in deposits of travertine, a type of limestone, at Kocaba?, in the Denizli basin, 100km south of where the flake was discovered. Recent estimates from sediments thought to be associated with these fossils suggested a likely age of between 1.3 million and 1.1 million years, but this work had many uncertainties.
Professor Darrel Maddy explains:
“Although the find of an individual struck flake may not in itself be unusual, the observation is significant because we can assign a precise time range to the artefact and thus the presence of hominins. We observed markings on the flake that clearly suggest it had been struck with force by a hard hammer or other stone tool, making it highly unlikely that it was shaped by natural processes.
“This quartzitic flake was then dropped on the floodplain of an active river meander. That meander cut through lavas with age estimates of 1.24 million years and was finally abandoned as a response to damming of the river downstream by a younger lava flow dated to 1.17 million years. This makes it the earliest securely-dated artefact from Turkey yet reported.”
Until recently, there has been little study of the river deposits of the ancestral Gediz River, despite abundant opportunity for determining their age, based upon their relationship to the lavas of the Kula volcanic field.
Professor Maddy added: “This study highlights the need for geologists and archaeologists to work more closely together. By doing so we should be able to track the movements of early humans with ever increasing detail, affording us great opportunities to understand the dispersal of our ancestors and the origins of the first Europeans.”
Link to the research paper: http://www.sciencedirect.com/science/article/pii/S0277379114004818
published on: 23 December 2014