Katja Douze

Senior Research Associate in Anthropology & African archaeology

  • T: +41 22 379 69 62
  • office 4-428A (Sciences II)
  • A West African Middle Stone Age site dated to the beginning of MIS 5: Archaeology, chronology, and paleoenvironment of the Ravin Blanc I (eastern Senegal). J Hum Evol 2021 Mar;154():102952. S0047-2484(21)00004-X. 10.1016/j.jhevol.2021.102952.


    The Ravin Blanc I archaeological occurrence, dated to MIS 5, provides unprecedented data on the Middle Stone Age (MSA) of West Africa since well-contextualized archaeological sites pre-dating MIS 4/3 are extremely rare for this region. The combined approach on geomorphology, phytolith analysis, and OSL date estimations offers a solid framework for the MSA industry comprised in the Ravin Blanc I sedimentary sequence. The paleoenvironmental reconstruction further emphasizes on the local effects of the global increase in moisture characterizing the beginning of the Upper Pleistocene as well as the later shift to more arid conditions. The lithic industry, comprised in the lower part of the sequence and dated to MIS 5e, shows core reduction sequences among which Levallois methods are minor, as well as an original tool-kit composition, among which pieces with single wide abrupt notches, side-scrapers made by inverse retouch, and a few large crudely shaped bifacial tools. The Ravin Blanc I assemblage has neither a chronologically equivalent site to serve comparisons nor a clear techno-typological correspondent in West Africa. However, the industry represents an early MSA technology that could either retain influences from the southern West African 'Sangoan' or show reminiscences of the preceding local Acheulean. A larger-scale assessment of behavioral dynamics at work at the transition period between the Middle to Upper Pleistocene is discussed in view of integrating this new site to the global perception of this important period in the MSA evolutionary trajectories.

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Research on behavioral transitions in human evolution

The focus of my research aims to unveil past behaviors and Human Evolution based on stone tool assemblages from the African Palaeolithic. I am a specialist of the Middle Stone Age period (ca. 300’000-20’000 years ago), which is known for the emergence of Homo sapiens, their first developments and their first diffusions within and out of Africa. More recently, I broadened my research to the end of the Early Stone Age (ca. 500’000 -250’000 years ago) and the beginnings of the Later Stone Age (ca. 30’000-15’000 years ago) in order to understand the mechanisms of behavioral changes over the long term.

My research is deeply rooted in the interaction of multidisciplinary approaches applied on the archaeological record. Past behavioral transitions are triggered by multifactorial processes, in which environmental (i.e., climate, availability of resources), socio-economic (i.e., innovation, group structure, demographic pressure), and biological changes (ie. genetics, adaptation) play important roles.

Current projects

I lead my research in different regions of Sub-Saharan Africa, including Western, Southern and Eastern Africa and I collaborate with institutions from across the continents as part of my international research network. I am also an active member of the international CoMSAfrica working group, which has the intention to construct a unified, systematic and replicable methodology for archaeologists working on stone tools in the African Middle Stone Age to enhance trans-regional comparisons. The SNF (grant # IZSEZ0_186545) funded the second international CoMSAfrica meeting that I organized at the University of Geneva in 2019.

Due to the uneven availability of data for these ancient periods, archaeological fieldwork is an essential part of my work and I am currently involved in several projects in different parts of Africa.

In West Africa

My main project is currently on West Africa, in the framework of the project “Human population and Paleoenvironments in Africa” led by Prof Eric Huysecom. I am coordinating the different research themes on the Palaeolithic occupations of the Falémé River Valley in Senegal, from the oldest hominin occupations to the replacement of hunter-gatherer populations by ceramic producers.

  • I am currently excavating and studying two new and well-preserved Acheulean sites in Senegal, on which an important dating program is ongoing. These sites will have a significant impact on the scientific community since Acheulean sites are largely unknown in this region as compared to the rest of Africa.
  • I lead the study of the oldest dated Middle Stone Age site of West Africa in Senegal, dated to ca. 125’000 years ago. The combined approach on archaeology, phytoliths, geomorphology and geochronology applied to this site is at the forefront of research in our field.
  • I am also supervising the study of more recent Middle Stone Age sites of the Falémé River Valley, on both stone tool remains and pigment use, which show unprecedented data for this region in Africa.

In the Horn of Africa

I work on Ethiopian sites since 2007 and occasionally on sites in Djibouti and Somaliland.

For my PhD, my work included the study of several Ethiopian sites dated between ca. >280’000 and 100’000 years ago (Gademotta and Kulkuletti), which are among the few reference sites for the beginnings of the Middle Stone Age in Africa. As an expert of Middle Stone Age technology, I contributed to the study of Laas Geel Shelter 7, in Somaliland, by showing the persistence of Middle Stone Age technical traditions into the Holocene.

  • Since 2008, I am involved in the “Later Stone Age sequence in Ethiopia” project coordinated by Prof François Bon from the University of Toulouse Jean-Jaurès and Ato Assamerew Dessie from the Ethiopian Authority for Research and Conservation of Cultural Heritage. In this framework, I am finalizing the study of different sites I excavated in the Ziway-Shala basin, in the main Ethiopian Rift Valley, dated to the end of the Middle Stone Age, between ca. 40’000 and 26’000 years ago, marking the transition to the Later Stone Age.
  • I am collaborating in the “Environmental Conditions and Settlement dynamics in the Horn of Africa during the Holocene” project in which I study the Late Pleistocene lithic remains found by Dr. Isabelle Crèvecoeur form the University of Bordeaux 1, in the sepulchral site of Hara Idé 3, Djibouti.
  • I am currently co-writing several regional syntheses on the patterns of changes characterizing the transition from the Middle to Later Stone Age in the Horn of Africa.

In South Africa

In the framework of my four years (March 2013- Dec. 2016) of Post-Doctoral research at the Evolutionary Studies Institute at the University of the Witwatersrand in Johannesburg, I worked on key sites for the Southern African Middle Stone Age. I was hosted by Christopher S. Henshilwood, Professor at the Chair of "The Origins of Modern Human Behavior" and worked at Blombos Cave (ca. 105-90’000 years ago) and Klipfrift Shelter (ca. 62-59’000 years ago) as well as on the ca. 150’000 years old layers of Bushman Rock Shelter (PI: Dr Guillaume Porraz and Dr Aurore Val).

  • My current involvement continues on the site of Blombos Cave in collaboration with Prof Christopher S. Henshilwood. I am leading a new study on specific stone tools potentially used in relation with the transformation of red pigments.

Lecturing on african paleolithic and stone tool studies

I am involved in the curriculum of both Bachelor and Master degrees in Prehistoric Archaeology at the University of Geneva, specifically on Palaeolithic studies, from the first tool productions (ca. 3.8 million years ago) to the later hunter-gatherer societies (ca. 10’000 years ago). I also teach the theory and practice to study stone assemblages, which could be applied to any geographical area and any time period. I train Swiss and African students on the field. I am also involved in the supervision of students at the bachelor, master and PhD level at the Anthropology Unit.

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