Hostname: page-component-7c8c6479df-7qhmt Total loading time: 0 Render date: 2024-03-28T14:23:01.233Z Has data issue: false hasContentIssue false

Quaternary environmental change in Cyrenaica evidenced by U-Th, ESR and OSL dating of coastal alluvial fan sequences

Published online by Cambridge University Press:  03 March 2015

John S. Rowan
Affiliation:
Department of Geography, University of Dundee
Stuart Black
Affiliation:
PRIS, University of Reading
Mark G. Macklin
Affiliation:
Institute of Geography and Earth Sciences, Aberystwyth
Brian J. Tabner
Affiliation:
Environmental Science Department, Lancaster University
John Dore
Affiliation:
Archaeology Department, University of Newcastle

Abstract

The coastal alluvial fan sequences of Cyrenaica are important archives of environmental change data, but hitherto relatively little has been known about their formative processes and rates. The Wadi Zewana coastal fan near Tolmeita was studied and a range of dating techniques (U-Th, ESR and OSL) applied to selected components of the stratigraphy. The sequence spans the last two global glacial periods separated by an Interglacial. Cemented alluvial fan gravel units yielded U-Th leachate-residue ages of 201 ± 18 ka, 179 ± 15 ka and 138 ± 8 ka respectively. The fan toe units are interdigitated with bioclastic beach rock deposits dated to 150 ± 10.9 ka corresponding to an Interglacial high stand in sea level and marine recession sequence featuring transgressive lag gravels, beach sand and cemented aeolian dunes dated to 121 ± 8 ka. Within the Wadi Zewana catchment a complex cut and fill history is evidenced. Aggradation phases dated to 76 ± 4 ka, 42.1 ± 5.1 ka and 12.5 ± 1.5 ka are broadly coincident with global glacials and stadials, whilst during the Last Interglacial and successive interstadials the drainage system underwent entrenchment, manifested on the coastal plain as telescopic fan segmentation and associated fan head trenching.

Type
Articles
Copyright
Copyright © Society for Libyan Studies 2000

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

Anketeil, J. M. and Ghellali, S. M. 1991. Quaternary fluvio-aeolian sand/silt and alluvial gravel deposits of northern Libya-event stratigraphy and correlation. Journal of African Earth Sciences 13: 457–69.CrossRefGoogle Scholar
Anketell, J. M. and Ghellali, S. M. 1995. Quaternary fluvio-aeolian sand/silt and alluvial gravel deposits of northern Libya-event stratigraphy and correlation. In: Lewin, J., Macklin, M. G. and Woodward, J. C. (eds.), Mediterranean Quaternary River Environments. Balkema, Rotterdam: 7995.Google Scholar
Belknap, D. F. 1999. Sea-level lowstand in the eastern Mediterranean: Late Pleistocene coastal terraces offshore northern Israel. Journal of Coastal Research 15: 399412.Google Scholar
Bruckner, H. 1986. Man's impact on the evolution of the physical environment in the Mediterranean region in historical times. GeoJournal 13: 717.CrossRefGoogle Scholar
Bull, W. B. 1991. Geomorphic Responses to Climatic Change, Oxford.Google Scholar
Clark, M. L., Rendell, H. M. and Wintle, A. G. 1999. Quality assurance in luminescence dating. Geomorphology 29: 173185.CrossRefGoogle Scholar
Fuller, I. C., Macklin, M. G., Lewin, J., Passmore, D. G. and Wintle, A. G. 1998. River response to high-frequency climate oscillations in southern Europe over the past 200 ky. Geology 26: 275278.2.3.CO;2>CrossRefGoogle Scholar
Gilbertson, D. D. and Chisholm, N. W. T. 1996. ULVS XXVIII: Manipulating the Desert Environment: ancient walls, floodwater farming and territoriality in the Tripolitanian pre-desert of Libya. Libyan Studies 27: 1752.CrossRefGoogle Scholar
Goni, M. F. S., Eynaud, F., Turon, J. L. and Shackleton, N. J. 1999. High resolution palynological record off the Iberian margin: direct land-sea correlation for the Last Interglacial complex. Earth and Planetary Science Letters 171: 123–37.CrossRefGoogle Scholar
Goudie, A. 1992. Environmental Change (3rd edition), Oxford.Google Scholar
Grun, R. 1989. Electron spin resonance (ESR) dating. Quaternary International 1: 65109.CrossRefGoogle Scholar
Harvey, A. M., Silva, P. G., Mather, A. E., Goy, J.-L., Stokes, M. and Zazo, C. 1999. The impact of Quaternary sea-level and climate change on coastal alluvial fans in the Cabo de Gata ranges, southeast Spain. Geomorphology 28: 122.CrossRefGoogle Scholar
Hey, R. W. 1968. The Quaternary geology of the Jabal Al Akhdar coast. In: Barr, F.T. (ed), Geology and Archaeology of Northern Cyrenaica, Libya. Petroleum Exploration Society of Libya. 10th Annual Field Conference. Tripoli: 159–65.Google Scholar
Hillaire-Marcel, C., Gariépy, C., Ghaleb, B., Goy, J.-L., Zazo, C. and Barceló, J.C. 1996. U-series measurement in Tyrrhenian deposits from Mallorca - further evidence for two last-interglacial high sea levels in the Balearic Islands. Quaternary Science Reviews 15: 5362.CrossRefGoogle Scholar
Ivanovich, M. and Harmon, R. S. 1992. Uranium Series Disequilibrium Applications to Environmental Problems, Oxford.Google Scholar
Kallel, N., Duplessy, J.-C., Labeyrie, L.Fontegne, M., Paterne, M. and Montacer, M. 2000. Mediterranean pluvial periods and sapropel formation over the last 200,000 years. Palaeogeography, Palaeoclimatology, Palaeoecology 157: 4558.CrossRefGoogle Scholar
Kelly, M., Black, S. and Rowan, J. S. 2000. A calcrete-based U-Th chronology for landform evolution in the Sorbas basin, southeast Spain. Quaternary Science Review 19: 9951010.CrossRefGoogle Scholar
Klitzsch, E. 1968. Outline of the geology of Libya. In: Barr, F.T. (ed), Geology and Archaeology of northern Cyrenaica, Libya. Petroleum Exploration Society of Libya. 10th Annual Field Conference. Tripoli, 7178.Google Scholar
Kraeling, C.H. 1962. Ptolemais, City of the Libyan Pentapolis, Chicago.Google Scholar
Lewin, J., Macklin, M. G. and Woodward, J. C. (eds.) 1995. Mediterranean Quaternary River Environments, Rotterdam.Google Scholar
McBurney, C. B. M. and Hey, R. W. 1955. Pre-history and Pleistocene Geology in Cyrenaican Libya, Cambridge.Google Scholar
Machette, M. N. 1985. Calcitic soils and calcretes of the southwestern United States. In: Weide, D. L. and Faber, M. L. (eds.) Soils and Quaternary geology of the southwestern United States. (Geological Society of America Special Paper 203): 121.Google Scholar
Nemec, W. and Postma, G. 1993. Quaternary alluvial fans in southwestern Crete: sedimentation processes and geomorphic evolution. In: Marzo, M. and Puigdefabregas, C (eds.) Alluvial Sedimentation (International Association of Sedimentologists, Special Publication 17): 235–76.CrossRefGoogle Scholar
Rendell, H. M. and Sheffer, N. L. 1996. Luminescence dating of sand ramps in the Eastern Mojave Desert. Geomorphology, 17: 187–97.CrossRefGoogle Scholar
Rose, J. and Meng, X. 1999. River activity in small catchments over the last 140 ka, North-east Mallorca, Spain. In: Brown, A. G. and Quine, T. A. (eds.), Fluvial Processes and Environmental Change, Chichester: 91102.Google Scholar
Sestini, G. 1984. Tectonic and sedimentary history of the NE African Margin (Egypt, Libya). In: Dixon, J. E. and Robertson, A. H. F. (eds.), Geological evolution of the eastern Mediterranean (Geological Society Special Publications), Oxford: 161–75.Google Scholar
Vita-Finzi, C. 1969. The Mediterranean Valleys, Cambridge.Google Scholar
Wild, M. T., Tabner, B. J. and Macdonald, R. 1999. ESR dating of quartz phenocrysts in some rhyolitic extrusive rocks using Al and Ti impurity centres. Quaternary Science Reviews 18: 15071514.CrossRefGoogle Scholar
Woodward, J. C. 1995. Archaeology and human-river interactions. In: Lewin, J., Macklin, M. G. and Woodward, J. C. (eds.) Mediterranean Quaternary River Environments, Rotterdam: 99102.Google Scholar