The Middle Pleistocene infilling of the Grotte des Rhinocéros (Casablanca, Morocco): geological and archaeological processes

Rué M.1,2, Lefèvre D.1, El Graoui M.3, Queffelec A.4, Daujeard C.5, Geraads D.6,7, Gallotti R.4, Delvigne V.4, 8, Mohib A.9, Raynal J.-P.4,7

  1. Université Paul-Valéry Montpellier 3, CNRS, MCC, UMR 5140, Archéologie des Sociétés Méditerranéennes, Montpellier, France, mathieu.rue@paleotime.fr
  2. Paléotime SARL, Villard-de-Lans, France,
  3. Institut National des Sciences de l’Archéologie et du Patrimoine (INSAP), Rabat, Maroc,
  4. Université Bordeaux, CNRS, MCC, UMR 5199, De la Préhistoire à l’Actuel : Culture, Environnement, Anthropologie, Talence, France,
  5. Muséum National d’Histoire Naturelle, Sorbonne Universités, CNRS, UMR 7194, Histoire Naturelle de l’Homme Préhistorique, Paris, France,
  6. Muséum National d’Histoire Naturelle, Sorbonne Universités, CNRS, UMR 7207, Centre de Recherche sur la Paléobiodiversité et les Paléoenvironnements, Paris, France.
  7. Max Planck Institute for Evolutionary Anthropology, Department of Human Evolution, Leipzig, Germany.
  8. Université de Liège, Service de Préhistoire, Belgium.
  9. Direction provinciale de la Culture, Kénitra, Maroc.

Abstract

Identifying the geological site formation processes allows to understand biases that affected the archaeological record. However, the lack of diagnostic sedimentary structures most often prevents the recognition of such processes. We present a geoarchaeological approach combining observations at different scales (from field to thin sections), geochemical characterizations and spatial analysis, allowing to determine which geological processes ruled the infilling of the Grotte des Rhinocéros site. Studied since 1991 for its rich mammals assemblage and Second Regional Acheulean assemblage, this marine cavity first developped within a complex of paleoshorelines of the Middle Pleistocene Oulad Hamida Formation (OH4 and OH5 members). The continental infilling sequence of at least 7 m thick, dated around 600 ka, consists of a superposition of yellowish biocalcarenitic units separated by red sandy units. The deposits have regularly recorded runoff and decantation structures suggesting low-energy water transport. The input of fine sediment from outside the cave by runoff is responsible for the exceptional preservation of paleontological and archaeological assemblages, but also for sorting and redistribution of some categories of remains. After burial, three main diagenetic phases have affected the infilling (alteration, cementation then dissolution). These new data permit to discuss the origin and homogeneity of the collected assemblages.


Subject Communication
Language of text English
Topics REG.002: Appearance, development and disappearance of the African Acheulean in the North Africa.
Keywords Acheulean; Middle Pleistocene; Morocco; Coastal Cave; Geoarchaeology;
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