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Single-grain OSL chronologies for Middle Palaeolithic deposits at El Mnasra and El Harhoura 2, Morocco: Implications for Late Pleistocene human-environment interactions along the Atlantic coast of northwest Africa

Journal Article


Abstract


  • Optically stimulated luminescence (OSL) measurements were made on individual, sand-sized grains of

    quartz from Middle Palaeolithic deposits at two cave sites (El Harhoura 2 and El Mnasra) on the Atlantic

    coast of Morocco. We were able to calculate OSL ages for 32 of the 33 samples collected from the Middle

    Palaeolithic deposits, including the earliest and latest Aterian levels at both sites. These ages reveal

    periods of occupation between about 110 and 95 ka (thousands of years ago), and at w75 ka. A late

    Middle Palaeolithic occupation of El Harhoura 2 is also recorded at w55 ka. Our single-grain OSL

    chronologies largely support previous age estimates from El Mnasra and other sites along the Atlantic

    coast of Morocco, but are generally more precise, reproducible and stratigraphically more coherent (i.e.,

    fewer age reversals). We compare the single-grain ages for El Harhoura 2 and El Mnasra with those

    obtained from single- and multi-grain OSL dating of Middle Palaeolithic deposits in the nearby sites of

    Contrebandiers and Dar es-Soltan 1 and 2, and with records of past regional environments preserved in

    sediment cores collected from off the coast of northwest Africa. A conspicuous feature of the new

    chronologies is the close correspondence between the three identified episodes of human occupation

    and periods of wetter climate and expanded grassland habitat. Owing to the precision of the single-grain

    OSL ages, we are able to discern gaps in occupation during Marine Isotope Stages 5 and 4, which may

    represent drier periods with reduced vegetation cover. We propose that these climatic conditions can be

    correlated with events in the North Atlantic Ocean that exert a major control on abrupt, millennial-scale

    fluctuations between wet and dry periods in northwest and central North Africa.

Publication Date


  • 2012

Citation


  • Jacobs, Z., Roberts, R. G., Nespoulet, R., El Hajraoui, M. A. & Debenath, A. (2012). Single-grain OSL chronologies for Middle Palaeolithic deposits at El Mnasra and El Harhoura 2, Morocco: Implications for Late Pleistocene human-environment interactions along the Atlantic coast of northwest Africa. Journal of Human Evolution, 62 (3), 377-394.

Scopus Eid


  • 2-s2.0-84858080771

Ro Metadata Url


  • http://ro.uow.edu.au/scipapers/4605

Number Of Pages


  • 17

Start Page


  • 377

End Page


  • 394

Volume


  • 62

Issue


  • 3

Abstract


  • Optically stimulated luminescence (OSL) measurements were made on individual, sand-sized grains of

    quartz from Middle Palaeolithic deposits at two cave sites (El Harhoura 2 and El Mnasra) on the Atlantic

    coast of Morocco. We were able to calculate OSL ages for 32 of the 33 samples collected from the Middle

    Palaeolithic deposits, including the earliest and latest Aterian levels at both sites. These ages reveal

    periods of occupation between about 110 and 95 ka (thousands of years ago), and at w75 ka. A late

    Middle Palaeolithic occupation of El Harhoura 2 is also recorded at w55 ka. Our single-grain OSL

    chronologies largely support previous age estimates from El Mnasra and other sites along the Atlantic

    coast of Morocco, but are generally more precise, reproducible and stratigraphically more coherent (i.e.,

    fewer age reversals). We compare the single-grain ages for El Harhoura 2 and El Mnasra with those

    obtained from single- and multi-grain OSL dating of Middle Palaeolithic deposits in the nearby sites of

    Contrebandiers and Dar es-Soltan 1 and 2, and with records of past regional environments preserved in

    sediment cores collected from off the coast of northwest Africa. A conspicuous feature of the new

    chronologies is the close correspondence between the three identified episodes of human occupation

    and periods of wetter climate and expanded grassland habitat. Owing to the precision of the single-grain

    OSL ages, we are able to discern gaps in occupation during Marine Isotope Stages 5 and 4, which may

    represent drier periods with reduced vegetation cover. We propose that these climatic conditions can be

    correlated with events in the North Atlantic Ocean that exert a major control on abrupt, millennial-scale

    fluctuations between wet and dry periods in northwest and central North Africa.

Publication Date


  • 2012

Citation


  • Jacobs, Z., Roberts, R. G., Nespoulet, R., El Hajraoui, M. A. & Debenath, A. (2012). Single-grain OSL chronologies for Middle Palaeolithic deposits at El Mnasra and El Harhoura 2, Morocco: Implications for Late Pleistocene human-environment interactions along the Atlantic coast of northwest Africa. Journal of Human Evolution, 62 (3), 377-394.

Scopus Eid


  • 2-s2.0-84858080771

Ro Metadata Url


  • http://ro.uow.edu.au/scipapers/4605

Number Of Pages


  • 17

Start Page


  • 377

End Page


  • 394

Volume


  • 62

Issue


  • 3