Structural analysis and geological modelling of a stratiform copper-cobalt deposit at Konkola, Central African Copper Belt, Zambia
Date
2024
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Abstract
The Konkola east mining block is one of the six mining blocks at Konkola mine owned by Konkola Copper Mines (KCM) in Chililabombwe Zambia. A structural analysis was carried out on the Konkola east mining block that assessed the main geological structures in the area and how they fit into the regional deformation history. The impact of the geological structures on short term mine planning was also assessed. The second part of this study involved creating a geological model and documenting the steps taken to create a workflow that can be applied to other parts of the mine.
Geological mapping was carried out on underground crosscuts and 23 boreholes were logged. Ten thin sections were studied using an Olympus BX53M/DP74 microscope. Old mine working plans containing historical geological information were scanned and digitized. A database was created and validated data was used to create a geological model of the ore bearing rock; the ore shale unit using Surpac mining software.
This study established that Konkola east has major normal faults striking north-south and low angle reverse faults striking east-west and sub- parallel to the regional fold axis. Parasitic folds were also identified. This configuration led to the interpretation of Konkola east as part of a larger dextral strike-slip fault system formed by north-south directed compression and east-west extension. Three main deformation phases were identified in this study and correlated with previous regional work. The earliest deformation resulted in the development of a bedding-parallel foliation due to burial. The second phase of deformation included the development of bedding parallel veins and the main folding event. The third phase involved the development of brittle structures including faults and three main joint sets. The main faults identified in this third deformation phase are thrust faults where the hangingwall block is observed to have moved up relative to the footwall block and normal faults where the hangingwall is observed to have moved down relative to the footwall.
These structures were found to have major implications for the short-term mining plan especially regarding ground stability and the mine hydrogeological environment. A geological model was successfully created and the total volume of the ore shale unit was estimated to be 1,032,199 m3 .
Description
A research report submitted in partial fulfilment of the requirements for the degree Master of Science in Economic Geology to the Faculty of Science, School of Geosciences, University of the Witwatersrand, Johannesburg, 2023
Keywords
Geological modelling, East mining, Mining