MINERALOGICAL ANALYSIS OF THE ETHIOPIAN RIFT: EXAMPLES FROM THE HSPDP HADAR FORMATION

The Ethiopian Rift, especially around the Awash River, is an important region for the study of early hominins and human evolution. This study presents preliminary analysis of sediments sampled from >240m of the Northern Awash core drilled by the international Hominin Sites and Paleolakes Drilling Project (HSPDP) in 2014. This is a first step in trying to understand climate change in the region and the environments of early hominins via mineralogical analysis.

These samples were brought to the lab and then were dried, powdered, and analyzed by X-ray diffraction to determine their mineralogy. The majority of the core lithologies are silt, clay, and basalt flows. Thin tephra and coarser grained sediments (sands and conglomerates) comprise a minor component of the core. Several different minerals were identified including quartz, calcite, feldspar, and albite in the samples analyzed. However, these samples also showed us a variety of different and less common minerals, including zeolites such as analcime. The zeolites may indicate an arid environment. Determining when this arid environment developed can help us understand climate change in the region.

Further work is continuing to examine the minerals in detail, throughout the stratigraphic column of the core. Determining what exactly happened during this time with accuracy, is of great value to understanding how climate change affected the evolution of early hominins.