caa a22 4500 445815388 CHVBK 20180317145226.0 cr unu---uuuuu 170323e20110801xx s 000 0 eng 10.1007/s10040-011-0730-5 doi (NATIONALLICENCE)springer-10.1007/s10040-011-0730-5 Evaluation of geologic and geomorphologic influences on borehole productivity in crystalline bedrock aquifers of Limpopo Province, South Africa [Elektronische Daten] [Martin Holland, Kai Witthüser] Evaluation des influences géologiques et géomorphologiques sur la productivité des forages d'eau dans les aquifères de socle cristallin de la province du Limpopo, Afrique du Sud Geologically complex crystalline aquifers underlie large parts of the semi-arid Limpopo Province where some of the greatest groundwater needs in South Africa occur. It is important to identify potentially high-yielding zones that can be targeted for water supply. The study covered four distinct geologic and morpho-structural domains within Limpopo Province, together covering about 23,500km2. Results from over 2,500 pumping test analyses indicate that bedrock type (e.g. pegmatite), lithological setting (e.g. aureole of granitoids), proximity and orientation of dykes and lineaments, topographic setting (e.g. slopes or valleys) and proximity of surface-water drainages may exert an influence on borehole productivity. No correlation between borehole productivity and weathering depth was found. Lineaments and dykes striking perpendicular to the current maximum horizontal stress seem to be more favourable targets, which is inconsistent with the predicted regime. Due to the complex geologic history, it is difficult to link open discontinuities to a distinct recent or past tectonic event. Regional stress-field data, as in this case, may not account for local, possibly highly significant, stress-field variations. The hydrogeologic importance of several factors related to groundwater occurrence, here presented, can be used as a working reference for future groundwater development programmes. Springer-Verlag, 2011 Crystalline rocks nationallicence Lineaments nationallicence Groundwater development nationallicence Transmissivity nationallicence South Africa nationallicence Holland Martin Department of Geology, University of Pretoria, 0002, Pretoria, South Africa aut Witthüser Kai Institute for Groundwater Studies, University of the Free State, 9300, Bloemfontein, South Africa aut Hydrogeology Journal Springer-Verlag 19/5(2011-08-01), 1065-1083 1431-2174 19:5<1065 2011 19 10040 https://doi.org/10.1007/s10040-011-0730-5 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10040-011-0730-5 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Holland Martin Department of Geology, University of Pretoria, 0002, Pretoria, South Africa aut NATIONALLICENCE 700 1- Witthüser Kai Institute for Groundwater Studies, University of the Free State, 9300, Bloemfontein, South Africa aut NATIONALLICENCE 773 0- Hydrogeology Journal Springer-Verlag 19/5(2011-08-01), 1065-1083 1431-2174 19:5<1065 2011 19 10040 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer