Geography

The Middle Awash paleoanthropological study area occupies a semiarid, relatively inaccessible part of the Afar rift inhabited by pastoralist Afar people living within the Afar Regional State of Ethiopia. The study area extends from Gewane town and the Arso River catchment in the south to the Talalak River in the north, and from the rift margin to the west to the asphalt Gewane-Adaitu highway to the east.

The Middle Awash study area is large compared to some sites like Olduvai Gorge, or Hadar.  This is because most fossil-bearing Middle Awash sediment outcrops are discontinuous, highly faulted, and very limited in spatial contiguity and extent.  Far less than a quarter of the study area has any paleoanthropological potential at all--many of the exposed sediments contain no fossils at all.  Much of the area is covered today by hardened basalt lava, recent river silts, vegetation, and water.

As a result, the Middle Awash is a research area comprising scattered, small windows of exposed but highly faulted sediments, instead of the long, temporally and spatially continuous outcrops characteristic of other sites such as Omo or Hadar.  Because of the unique geology, the Middle Awash reveals many small windows into the past rather than a longer, more continuous succession of sediments.  Correlating these windows based on geology, paleontology, and archaeology is a major part of the project's ongoing research.

To understand the prehistory of the Middle Awash, project archaeologists, geologists, and paleontologists have to coordinate and integrate their research.  The ongoing research is therefore devoted to studying the deposits comprehensively.  Using detailed stratigraphy and tephrachronology, guided by biochronology, various aerial imaging platforms, and ground survey, the Middle Awash geology team is working to build a framework of knowledge about the processes that shaped this single valley during the last six million years.  All of the archaeological and paleontological resources are studied within this chronostratigraphic framework.