Lineament and pegmatite mapping using landsat TM imagery and aerial photograph data: Kaseba-Katota Area, Serenje district, Central Zambia
Date
2012-09-17
Authors
Nkemba, Simon
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
The Kaseba-Katota area is part of the Mesoproterozoic Irumide fold belt trending in a northeast - southwest direction and covers part of the Eastern and Central provinces of Zambia. Outcrops in the area include metasediments, which have been subjected to intense deformation resulting in strong foliation, recumbent and overturned folding. In places, the rocks seem to have undergone anatexis as indicated by ductile flow structures and heavily silicified layers. The general trend of foliation and schistosity is northeast - southwest. Foliation planes are mainly vertical or dip steeply to the east. The northeast - southwest Irumide structures are in places interfered by northwesterly trending structures of the Pan African Lufilian Orogeny. The rocks are characterised by vertical faults and joint patterns. The dominant joint pattern strikes between 30° -80°.Pegmatites in the Kaseba-Katota area commonly occur as lensoids and rarely form extensive and continuous tabular bodies. Most of the pegmatites in the belt are small, varying from 10 to 50 m in length and usually form small hills rising above the general surrounding up to about 6 m high. The pegmatites are associated with migmatites, schists, and micaceous quartzites. The contacts between the pegmatites and the host rocks range from very sharp to gradational. Chief minerals of the pegmatites are quartz, feldspar and mica. Most of the pegmatites have been exploited commercially for aquamarine, beryl, tourmaline and garnet. Although the pegmatites host abundant muscovite and feldspar, these have not been exploited. A digital database of the Kaseba - Katota area consists of geology, lineaments, faults (interpreted from Landsat Thematic Mapper (TM) image and aerial photographs), joints and foliation traces (mapped in the field). Remote sensing techniques. Geographic Information Systems (GIS) as well as statistical analyses applied to this digital database and the resulting maps show that the strike of economical important pegmatites is parallel and controlled by NNE to ENE - trending lineaments, foliation and joints in the area. The conceptual model shows that the rifting of the continental crust started around 1700 Ma followed by tectonic events some of which were responsible for the emplacement of the pegmatites and ended in the Pan-African Orogeny. This thesis therefore, applied remote sensing techniques and GIS techniques for lineament mapping and generation of a conceptual model as a tool for delineating target areas for pegmatite exploration.
Description
Keywords
Pegmatites -- Zambia , Landsat satellites -- Serenje -- Zambia