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Current models of early hominin biological and cultural evolution are shaped almost entirely by the data accumulated from the East African Rift System (EARS) over the last decades. In contrast, little is known about the archaeological record from the high-elevation regions on either side of the Rift. Melka Wakena is a newly discovered site-complex on the Southeastern Ethiopian Highlands (SEH) (>2300 m above mean sea level) just east of the central sector of the Main Ethiopian Rift (MER), where eight archaeological and two paleontological localities were discovered to date. Nine archaeological horizons from three localities were tested so far, all dated to the second half of the early Pleistocene (∼1.6 to >0.7 Ma). All the lithic assemblages belong to the Acheulian technocomplex. Here we report on geochronological, stratigraphic, paleontological and lithic technological aspects of the tested localities and contextualize them in the broader framework of hominin cultural evolution in eastern Africa. Findings from Melka Wakena, assessed against the backdrop of the few other highland sites (Melka Kunture and Gadeb), support a scenario of expansion rather than dispersal from the Rift to the highlands. When considered in the context of the Rift-highlands interface, results of the first-phase research at Melka Wakena help to parse existing general models into archaeologically testable hypotheses and demonstrate the site’s potential to contribute to research of early prehistory and to understanding the dynamics of early Pleistocene hominin populations in eastern Africa.

The Melka Wakena archaeological site-complex is located at the eastern rift margin of the central sector of the Main Ethiopian Rift (MER), in south central Ethiopia. This wide, gently sloping rift shoulder, locally called the “Gadeb plain” is underlain by a succession of primary pyroclastic deposits and intercalated fluvial sediments as well as reworked volcaniclastic rocks, the top part of which is exposed by the Wabe River in the Melka Wakena area. Recent archaeological survey and excavations at this site revealed important paleoanthropological records. An integrated stratigraphic, petrological, and major and trace element geochemical study has been conducted to constrain the petrogenesis of the primary pyroclastic deposits and the depositional history of the sequence. The results revealed that the Melka Wakena pyroclastic deposits are a suite of mildly alkaline, rhyolitic pantellerites (ash falls, pumiceous ash falls and ignimbrites) and slightly dacitic ash flows. These rocks were deposited by episodic volcanic eruptions during early to middle Pleistocene from large calderas along the Wonji Fault Belt (WFB) in the central sector of the MER and from large silicic volcanic centers at the eastern rift shoulder. The rhyolitic ash falls, pumiceous ash falls and ignimbrites have been generated by fractional crystallization of a differentiating basaltic magma while the petrogenesis of the slightly dacitic ash flows involved some crustal contamination and assimilation during fractionation. Contemporaneous fluvial activities in the geomorphologically active Gadeb plain deposited overbank sedimentary sequences (archaeology bearing conglomerates and sands) along meandering river courses while a dense network of channels and streams have subsequently down-cut through the older volcanic and sedimentary sequences, redepositing the reworked volcaniclastic sediments further downstream.

Archaeological reconnaissance and test excavation conducted in south-central Ethiopia reveal the region's rich Stone Age and Holocene archaeology. Ongoing lithic, faunal and dating analyses aim to understand chronological and behavioural contexts of prioritised rockshelters as part of a newly launched project. Speleothems in some of the caves promise high-resolution palaeoclimatic reconstruction.

Recent claims about early tool making and use have proved controversial (1⇓⇓–4). In PNAS, Braun et al. (5) report Oldowan artifacts from Ledi-Geraru, Ethiopia. The claimed minimum age of 2.581 Ma for these artifacts would, even if accurate, imply a marginally older beginning for the Oldowan than the ∼2.58 Ma previously established ∼35 km to the west at Gona (6). While the Ledi-Geraru assemblage is a welcome addition to the limited number of early Oldowan occurrences, its bearing on our current understanding of the earliest tools and their makers (6, 7) is contingent on the accuracy of the inferred … [↵][1]1To whom correspondence may be addressed. Email: yonatan.sahle{at}ifu.uni-tuebingen.de. [1]: #xref-corresp-1-1

The site of Aladi Springs was discovered and excavated in the 1970s. However, the assemblages from this site did not subsequently receive full investigation. Here, we present results of the first exhaustive analysis of the lithic collections from both the Middle and the Later Stone Age (MSA/LSA) occupation horizons at this site. Detailed analysis of metric and non-metric attributes reveals a marked variability in production techniques and overall size of major tool classes, with dimensional diminution evident across these occupations. However, tool utilisation patterns exhibit an overall similarity where marginally retouched tools and inverse retouch techniques appear to be the characteristic features of both industries. Whereas the presence in the MSA occupation of tool forms with LSA affinities suggests that the site may actually represent a transitional context, additional excavations and/or detailed microstratigraphic studies are needed in order to establish unequivocally the actual cultural trajector...