Melka Kunture, as it can be seen today, is part of a gently undulating landscape of the Upper Awash Valley, in the highlands of Ethiopia, at c. 2000m asl. All over the Upper Pliocene and the Pleistocene, tectonic activity led to the deepening of the demi-graben depression where the meandering paleo-Awash deposited alluvia. Through time, parts of the paleo-landscape were buried again and again, blanketed both by alluvial deposits, and by volcanic deposits produced by the nearby volcanoes. Accordingly, past surfaces, littered with archaeological implement and prehistoric animal remains, were covered by sediments and escaped destruction. There is now evidence by natural erosion on the banks of the little gullies of the local tributaries of the Awash.
Archaeological excavations allowed for the recovery of the prehistoric heritage and of the related scientific information. More than 80 archaeological layers have been identified during 50 years of archaeological research; 30 of them have been extensively excavated over surfaces ranging from 50 m2 to 250 m2. Tens of thousands of lithic tools, faunal and sometime human remains (Homo erectus sensu lato and archaic Homo sapiens) have been discovered. Many more are preserved in an area of more than 100 km2, and wait for future research and for future generations of scholars.
The visible thickness of these deposits is around 30 m, but the cumulative thickness of the various levels is about 100 m. The archaeological deposits of Melka Kunture are a unique archive of human evolution, spanning over more than 1.7 million years, from Oldowan layers, to a very long and complex sequence of Acheulean layers, to Middle Stone Age and eventually by Late Stone Age layers. All over this sequence, a diversified range of lithic raw materials of volcanic origin were available for knapping by humans: each had different properties and qualities, all were carefully tested and, when found suitable, were eventually exploited. The volcanic rocks utilized for knapping were different types of basalts, ignimbrites, trachytes and trachybasalts on one hand, and obsidian on the other hand. These two groups of raw materials present completely different qualities for stone knapping. Accordingly, Melka Kunture can be seen as a laboratory for human evolution, where the requisites for trial and error procedures were naturally available, fostering the development of cognitive capabilities in humans.
Obsidian is especially important, and appears virtually at each site, starting from the archaeological record with the Oldowan at 1.7 million years. At some sites obsidian is the only material used. The primary source is Balchit, a dome-flow which is also part of the archaeological area. Erosion of the Balchit outcrops and re-deposition by the tributaries of the Awash eventually led to the formation of rich and numerous secondary sources, which did not escape from the attention of prehistoric humans. Obsidian exploitation was still under way in recent historic times, when this naturally occurring volcanic glass was used in everyday activities, as in curing animal hides. The obsidian dome-flow of Balchit is spotted by extensive flaking areas. Cores, flakes, blades and debris have accumulated on thousands of square meters since prehistory and well into historic times.