Hostname: page-component-586b7cd67f-dlnhk Total loading time: 0 Render date: 2024-11-30T17:31:02.385Z Has data issue: false hasContentIssue false

DMP XV: Palaeohydrology and Palaeoenvironment: Initial Results and Report of 2010 and 2011 Fieldwork

Published online by Cambridge University Press:  24 April 2014

Nicholas Drake
Affiliation:
Department of Geography, King's College, London, UK
Mustapha Salem
Affiliation:
Earth Sciences Department, al-Fateh University, Tripoli, Libya
Simon Armitage
Affiliation:
Department of Geography, Royal Holloway University of London, UK
Jan Francke
Affiliation:
Department of Geography, King's College, London, UK
Mark Hounslow
Affiliation:
Lancaster Environment Centre, Lancaster University, Lancaster, UK
Osama Hlal
Affiliation:
Earth Sciences Department, al-Fateh University, Tripoli, Libya
Kevin White
Affiliation:
Department of Geography, University of Reading, Reading, UK
Ahmed El-Hawat
Affiliation:
Earth Sciences Department, University of Garyunis, Binghazi, Libya

Abstract

This paper reports the results of fieldwork conducted in the 2010 and 2011 DMP field seasons and of analysis of samples collected during these and previous years. Research has involved 1) studying palaeolake sediment outcrops, 2) using ground penetrating radar (GPR) to determine their extent under the Dahān Ubārī, and 3) coring palaeolakes in order to determine their palaeoenvironmental records. Research on these samples is continuing but some initial findings are discussed in this paper. The most extensive palaeolake sediments are found within the al-Mahruqah Formation and were deposited by a giant lake system that developed in the Fazzān Basin during past humid periods. Stratigraphic analysis of Lake Megafazzān sediments suggests two different sedimentary successions, a lake margin succession distinctive for its lacustrine and palaeosol carbonates, and a clastic-dominated, intensely rootleted, basin-centre succession which has terrestrial intervals (aeolian and palaeosols) as well as in the upper parts lacustrine limestones. Both basin margin and basin centre successions are underlain by fluvial deposits. Magnetostratigraphy suggests that the formation may be as old as the mid-Pliocene. After the Lake Megafazzān phase, smaller palaeolakes developed within the basin during subsequent humid periods. One of the largest is found in the Wādī al-Hayāt in the area between Jarma and Ubārī. Similar deposits further west along the Wādī at progressively higher altitudes are interpreted as small lakes and marshes fed by springs issuing from aquifers at the base of the escarpment, last replenished during the Holocene humid phase. Dating of sediments suggests that this was between c. 11 and c. 8 ka. The Wādī ash-Shāţī palaeolake core also provides a Holocene palaeoclimate record that paints a slightly different picture, indicating lake conditions until around 7 ka, whereupon it started oscillating until around 5.5 ka when sedimentation terminates. The reasons for the differences in these records are discussed.

Type
Archaeological Reports
Copyright
Copyright © Society for Libyan Studies 2011

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Armitage, S.J., Drake, N.A., Stokes, S., El-Hawat, A., Salem, M.J., White, K.Turner, P. and McLaren, S. J. 2007. Multiple phases of North African humidity recorded in lacustrine sediments from the Fazzan Basin, Libyan Sahara, Quaternary Geochronology 2: 181186.CrossRefGoogle Scholar
Brooks, N., Drake, N., MacLaren, S. and White, K. 2003. Studies in Geography, Geomorphology, Environment and Climate. In Mattingly, D.J., Dore, J. and Wilson, A.I. (eds), The Archaeology of Fazzān Volume I: Synthesis. London: Society for Libyan Studies, Department of Antiquities: 3774.CrossRefGoogle Scholar
Drake, N.A., White, K., Salem, M., Armitage, S., El-Hawat, A., Francke, J., Hounslow, M. and Parker, A. 2009. DMP VIII: Palaeohydrology and palaeoenvironment, Libyan Studies 40: 171178.CrossRefGoogle Scholar
Drake, N.A., El-Hawat, A.S., Turner, P., Armitage, S.J., Salem, M.J., White, K.H. and McLaren, S. 2008. Palaeohydrology of the Fazzan Basin and Surrounding Regions: the Last 7 Million Years. Palaeogeography, Palaeoclimatology, Palaeoecology 263: 131145.CrossRefGoogle Scholar
Geyh, M.A. and Thiedig, F. 2008. The Middle Pleistocene Al Mahrúqah Formation in the Murzuq Basin, northern Sahara, Libya evidence for orbitally-forced humid episodes during the last 500,000 years, Palaeogeography, Palaeoclimatology, Palaeoecology 257: 121.CrossRefGoogle Scholar
Gundobin, V.M. 1984. Geological Map of Libya, 1:250,000. Sheet: Qararat Al Marar (NH 33-13) Explanatory Booklet. Industrial Research Centre, Tripoli.Google Scholar
Lahr, M.M., Armitage, S., Barton, H., Crivellaro, F., Drake, N., Foley, R., Maher, L., Mattingly, D., Salem, M., Stock, J. and White, K. 2008. DMP III: Pleistocene and Holocene palaeonvironments and prehistoric occupation of Fazzan, Libyan Sahara. Libyan Studies 39: 263294.CrossRefGoogle Scholar
Mattingly, D., Lahr, M., Armitage, S., Barton, H., Dore, J., Drake, N., Foley, R., Merlo, S., Salem, M., Stock, J. and White, K. 2007. Desert Migrations: people, environment and culture in the Libyan Sahara. Libyan Studies 38: 115156.CrossRefGoogle Scholar
Thiedig, F.M., Oezen, D., El-Chair, M. and Geyh, M.A. 2000. The absolute age of the Quaternary lacustrine limestone of the Al Mahruqah Formation – Murzuq Basin, Libya. In Sola, M.A. and Worsley, D. (eds), Geological Exploration in the Murzuq Basin. Elsevier, Amsterdam: 89116.CrossRefGoogle Scholar