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Títol:
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Karst in southern Africa |
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Autor/es
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Marker, Margaret E.
; Gamble, Frances Margaret |
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Matèries en català:
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Geologia ; Geografia. |
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Matèries en anglès:
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Geology ; Geography. |
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Resum-Abstract:
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[spa] En el presente trabajo los autores proceden a la descripción de restos mandibulares, hallados en los depósitos pleistocénicos de las cavidades subterráneas de Mallorca y pertenecientes a Myotragus balearicus BATE, que ofrecen la particularidad de presentar dos incisivos en cada rama mandibular. Todas ellas corresponden a animales jóvenes.
[eng] The paper reviews the distribution of karst rocks in southern Africa and distinguishes between two dominant types: the sparitic Proterozoic dolomitic limestones of the interior plateaux and the Tertiary micritic sandy limestones of the coast. The density of surface karst forms is variable and low by comparison with overseas regions. Caves are shallow phreatic in origin and may contain massive speleothem development. Two major phases of growth are recognised. Modern precipitation is minor. The major karst forming period is believed to be of considerable antiquity. The impacts on southern African karst range from changes to the geohydrology due to economic extraction, mine dewatering and changes to the surface cover, to direct effects of mining particularly for gold, for bat guano and formerly for speleothems. Some host rock is directly mined for use in steel making. Pollution is so far of minor importance. Caves near major population centres suffer user impact which is often inadvertent. The consequences of a new military installation near Bredasdorp are being monitored. In southern Africa the basis exists for effective management programmes. |
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Font:
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Endins 1987, Vol. 13, pp. 93-98 |
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Identificador:
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e-ISSN: 2386-7299 |
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Tipus de document:
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info:eu-repo/semantics/article ; info:eu-repo/semantics/publishedVersion |
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Avís legal:
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all rights reserved ; info:eu-repo/semantics/openAccess |
