A 61 cm core through a speleothem column in Drotsky's Cave, Botswana, has yielded a U-series dated pollen record of Holocene vegetation changes in the Kalahari Desert. Between c.10000-7000BP, the site was surrounded by an arid grassland with dry-adapted trees and shrubs such as Acacia and Commiphora. An increase in pollen of Combretaceae and Cyperaceae, and the appearance of pollen of such mesic savanna plants as Grewia between c. 7000—6000 BP, may indicate the onset of slightly wetter conditions. Combretaceae and other mesic pollen types increase between c. 6000-3000 BP, but the late Holocene record appears variable, with the period c. 5000-4000 BP being somewhat dryer than the millennia before and after. It would appear that Kalahari vegetation has changed less during the Holocene than many other African environments previously investigated. Despite the limitations imposed by pollen analysis of cave sites, the record from Drotsky's Cave shows good agreement with regional trends derived from other studies. The use of U-series dated pollen spectra derived from speleothems holds potential for expanding the geographic scope of palynological studies to areas lacking suitable lakes and bogs, and for extending the dated pollen record back an order of magnitude beyond the 14C timescale.
Avery, D.M.1981: Holocene micromammalian faunas from the northern Cape Province, South Africa. South AfricanJournal of Science77, 265-73.
2.
Bard, E., Hamelin, B., Fairbanks, R.G. and Zindler, A.1990: Calibration of the 14C timescale over the past 30000 years using mass spectrometric U-Th ages from Barbados corals. Nature345, 405-10.
3.
Barnes, J.E. and Turton, L.M.1986: A list of the flowering plants of Botswana in the Herbaria at the National Museum, Sebele andUniversity of Botswana . Gaborone: Botswana Society.
4.
Beaumont, P.B., Van Zinderen Bakker, E.M. and Vogel, J.C.1984: Environmental changes since 32000BP at Kathu Pan, northern Cape. In Vogel, J.C., editor, Late Cainozoic palaeoclimates of the Southern Hemisphere. Rotterdam: Balkema, 329-38.
5.
Beaumont, P.B. and Vogel, J.C.1993: What turned the young tufas on at Gorrokop? South AfricanJournal of Science89, 196-98.
6.
Bonnefille, R. and Riollet, G.1980: Pollens des savanes d'Afrique orientale. Paris: CNRS.
7.
Brook, G.A., Burney, D.A. and Cowart, J.B.1990: Desert paleoenvironmental data from cave speleothems with examples from the Chihuahuan, Somali-Chalbi, and Kalahari Deserts. Palaeogeography, Palaeoclimatology, Palaeoecology76, 311-29.
8.
Burney, D.A.1987a: Presettlement changes at Lake Tritrivakely, Madagascar . Palaeoecology of Africa18, 350-81.
9.
— 1987b: Late Holocene vegetational change in central Madagascar . Quaternary Research28, 130-43.
Burney, D.A. and Burney, L.P.1993: Modem pollen deposition in cave sites: experimental results from New York State. New Phytologist124, 523-35.
12.
Burney, D.A., Burney, L.P., Rafamantanantsoa, J.G., D'Arrigo, R.D. and Jacoby, G.C.1993: Laminated sediment cores, tree ring records, and laminated speleothems from Madagascar. Eos4/20, 93.
13.
Butzer, K.W.1984a: Archaeogeology and Quaternary environment in the interior of southern Africa. In Klein, R.G. , editor, Southern African prehistory and paleoenvironments . Rotterdam: Balkema, 1-64.
14.
—— 1984b: Late Quaternary environments in South Africa. In Vogel, J.C., editor, Late Cainozoic palaeoclimates of the SouthernHemisphere. Rotterdam: Balkema, 235-64.
15.
Butzer, K.W., Fock, G.J., Stuckenrath, R. and Zilch, A.1973: Palaeohydrology of late Pleistocene Lake Alexandersfontein, Kimberley, South Africa. Nature243, 328-30.
16.
Butzer, K.W., Stuckenrath, R., Bruzewicz, A.J. and Helgren, D.M.1978: Late Cenozoic palaeoclimates of the Gaap Escarpment, Kalahari margin, South Africa. Quaternary Research10, 310-39.
17.
Cooke, H.J.1975: The palaeoclimatic significance of caves and adjacent landforms in the Kalahari of western Ngamiland, Botswana. Geographical Journal143, 431-44.
18.
—— 1984: The evidence from northern Botswana of late Quaternary climate change. In Vogel, J.C., editor, Late Cainozoic Palaeoclimates of the SouthernHemisphere. Rotterdam: Balkema , 265-78.
19.
Cooke, H.J. and Baillieul, T.1974: The caves of Ngamiland: an interim report on explorations and fieldwork 1972-74. Botswana Notes and Records6, 147-56.
20.
Cooke, H.J. and Verhagen, B.T.1977: The dating of cave development - an example from Botswana . Proceedings of the 7th International Congress of Speleology, Sheffield, 122-24.
21.
Cooke, H.J. and Verstappen, H.T.1984: The landforms of the western Makgadikgadi Basin in northern Botswana, with a consideration of the chronology of the evolution of Lake Paleo-Makgadikgadi. Zeitschrift für Geomorphologie NF28, 1-19.
22.
Faegri, K. and Iversen, J.1975: Textbook of pollen analysis. New York : Hafner.
23.
Grey, D.R.C. and Cooke, H.J.1977: Some problems in the Quaternary evolution of the landforms of northern Botswana. Catena4, 123-33.
24.
Hamilton, A.C. and Perrott, A.C.1980: Modem pollen deposition on a tropical African mountain . Pollen et Spores22, 437-68.
25.
Laseski, R.A.1983: Modem pollen data and Holocene climate change in eastern Africa. Unpublished Ph.D. thesis, Brown University , Providence, Rhode Island.
26.
Scott, L.1982: A late Quaternary pollen record from the Transvaal Bushveld, South Africa. Quaternary Research17, 339-70.
27.
— 1987: Pollen analysis of hyena coprolites and sediments from Equus Cave, Taung, Southern Kalahari (South Africa). Quaternary Research28, 144-56.
28.
—— 1989: Climatic conditions in southern Africa since the Last Glacial Maximum, inferred from pollen analysis. Palaeogeography, Palaeoclimatology, Palaeoecology70, 345-53.
29.
Scott, L., Cooremans, B., de Wet, J.S. and Vogel, J.C.1991: Holocene environmental changes in Namibia inferred from pollen analysis of swamp and lake deposits. The Holocene1, 8-13.
30.
Shaw, P.A.1986: The palaeohydrology of the Okavango Delta: some preliminary results. Palaeoecology of Africa17, 51-58.
31.
Shaw, P.A. and Cooke, H.J.1986: Geomorphic evidence for the late Quaternary palaeoclimates of the middle Kalahari of northern Botswana. Catena13, 349-59.
32.
Shaw, P.A. and Thomas, D.S.G.1988: Lake Caprivi - a late Quaternary link between the Zambezi and middle Kalahari drainage systems. Zeitschrift für Geomorphology NF32, 329-37.
33.
Thomas, S.G. and Shaw, P.A.1991: The Kalahari environment. Cambridge : Cambridge University Press.
34.
Van ZinderenBakker, E.M.1982: Pollen analytical studies of the Wonderwerk Cave, South Africa. Pollen et Spores24, 235-50.
35.
Vincens, A.1984: Environnement végétal et sedimentation pollinique lacustre actuelle dans le basin du Lac Turkana (Kenya). Revue Paléobiologique . In Act. 5° Cong. Ass. Palynol. Langue Fr.: Palynologie et paléobotanique. 235-42.
