Late Pleistocene and Holocene lake level fluctuations in the Lake Bogoria bassin, northern Kenya Rift Valley in Palaeoecology of Africa and the surrounding islands-Vol 13.
Lake Bogoria is a closed-basin, saline alkaline lake in the Kenya Rift Valley. The sedimentology and mineralogy of three long drill-cores from the lake floor, and the marginal fluvio-deltaic and littoral deposite are studied here. During the late
Pleistocene, the lake fluctuated but was mostly low and saline (anoxic)| calcrete, dolocrete and pedogenic zeolites developed in marginal soils. Following this dry phase, a regional increase in humidity during the terminal Pleistocene and early Holocene, led
to a marked rise in lake level. The lake waters were considerably fresher than today allowing expansion of both fauna and flora, and may periodically have overflowed northwards into the Baringo sub-basin. Further fluctuations occured throughout the Holocene
Late Quaternary history of Lake Besaka, Ethiopa in Palaeoecology of Africa and the surrounding islands-Vol 13.
Lake Besaka, as a groundwater-fed lake which appears to have overflowed eastwards into the Awash during the late Pleistocene and perhaps again during the earliest Holocene, is not a sensitive indicator of climatic change. Only two major
transgressions are so far evident in the late Quaternary depositional record of the lake, one dated to about 11,000-12,000 BP, the other perhaps 10,000 years older. Tectonic and volcanic factors have undoubtedly modulated the response of Lake Besaka to climatic
High levels of Lake Malawi during the Late Quaternary in Palaeoecology of Africa and the surrounding islands. Volume 15. Southern African Society for Quaternary research. Proceedings.
Lake Malawi levels have been as much as 5 m above modern peak values during the early? Holocene but, until more is known about changes in the overflow, the palaeoclimatic significance of these high levels must remain in doubt. In an attempt to view
modern flooding problems in the longer term perspective, beaches representing high lake levels within approximately the last 2 000 years are being studied in detail.
Further Late Quaternary leaf fossils from Lake Bosumtwi, Ghana in Palaeoecology of Africa and the surrounding islands-Vol 13.
A further 12 species of tree brave been identified from leaf fossils preserved in terminal Pleistocene-early Holocene lacustrine sediments exposed above the present shore of Lake Bosumtwi. Our earlier finding has been confirmed that forest
A detailed account is presented of the sediments and diatoms of the Middle Pleistocene Olorgesailie Formation. Facies distributions suggest a lake that was centred on the Koora Graben and which periodically expanded over an area to the north of Mt
Olorgesailie. The mineralogy and provenance of the sediments are discussed. The stratigraphic distribution of diatom associations suggest many lake level fluctuations. Alkalinities varied between about 5 and 85 meq/l. Based on alkalinity changes, three main
Fossil pollen of the upper 30 m of a core with a length of 162 m taken near the shore of Lake Abiyata in the Ethiopian Rift Valley has been analysed. The results are compared with surface pollen spectra of different vegetation types. The sequence
covers the time span of approximately 40 000 to 6 000 years BP. The pollen spectra give indications of semi-arid and more humid periods while colder intervals may have occurred. The results are correlated with changes in lake levels.
nearer to the modern lake. A large pyroclastic flow swept into northern Malawi from the Rungwe area just over 11 000 300 yr BP. An ash layer in the sediments flooring Lake Tanganyika, dated at 11 690 300 yr BP, may be the air-fall equivalent of the same
Faunal and floral remains, changing lake levels, and a series of 15 radiocarbon dates from south-central Mauritania document climatic changes in the period c. 4500 to 2300 BP and provide the basis for estimation of mean annual precipitation greater