Abstract
The Tsodilo Hills Group strata exposed in the Tsodilo Hills are an association of meta-arenites, meta-conglomerates, quartz-mica schists, sandstone, red siltstone and sedimentary breccia deposited on an open siliciclastic marine shelf between the Late Palaeoproterozic and Late Mesoproterozoic, and outcropping in NW Botswana. The succession is dominated by three micaceous quartzite units interlayered with subordinate lenses and wedges of other rock types. Facies gradients from S to N are expressed by decreasing content of muscovite at all levels of metasediment organisation from thin wedge-shaped units to thick quartzite complexes, as well as a decrease in pebble content and increase in the arenaceous matrix in some metal conglomerate beds, matching regional palaeotransport direction. Well-rounded pebbles of rocks are flat, suggesting redeposition from a beach environment. Lenticular conglomeratic bodies with erosional lower boundaries represent infills of local incisions in the sandy bottom sediments. The abundance of laterally discontinuous lithological units reflects shelf palaeotopography controlled and modified by deposition and migration of large bed forms, ranging from megaripple marks (or submarine dunes) to sand waves. Deposition was influenced by tides and two regressive events. The older regression resulted in a marker unit of tidal mudflat-related red-bed facies: mudstone, siltstone, channel-fill sandstone and sedimentary breccia. The second regression is indicated by a tabular conglomerate marker reflect-ing increased input of coarse terrigenous material.
Highlights
The Tsodilo Hills rise over 420 m above the surrounding Kalahari Desert in NW Botswana in the region where the Neoproterozoic Damara belt crosses the country (Fig. 1)
This Pan African orogen extends from Zambia and Congo in the NE, where it is known as the Katangan belt, or the Lufilian Arc, to Namibia in the SW
Considering that, the aim of this paper is to present the lithostratigraphic classification of the Tsodilo Hills Group based on as yet unpublished fieldwork results, integrating lithological features with fundamental sedimentological characteristics
Summary
The Tsodilo Hills rise over 420 m above the surrounding Kalahari Desert in NW Botswana in the region where the Neoproterozoic Damara belt crosses the country (Fig. 1). This Pan African orogen extends from Zambia and Congo in the NE, where it is known as the Katangan belt, or the Lufilian Arc, to Namibia in the SW. Based upon an 40Ar/39Ar age of 490.0 ±2.3 Ma on muscovite grains from quartz-muscovite schist (Singletary et al 2003), interpreted as the age of cooling after regional metamorphism, the regional position and lithological similarities with some units of the Damara Belt in Namibia, a Neoproterozoic age of the Tsodilo Hills Group was initially suggested (Wendorff 2005). The Tsodilo Hills metasedimentary rocks are much older than thought previously and appear to be age-equivalent to several sedimentary rock units known in Africa as parts of the Kalahari Craton, Congo and Congo-Tanzania Craton as well as in South America within the São Francisco Craton (Mapeo et al 2019)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
