Resource Estimation of Mantraim Central Gold Deposit, Teberebie Mines, Western Region, Ghana
Date
2014-02
Authors
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Publisher
University Of Ghana
Abstract
Gold Fields Ghana Limited (GFGL) has several gold mining concessions situated in Ghana with granted Mining Leases of which the Teberebie Mine is an essential part and still in production. The Teberebie Mine which is found within the Takwaian district is located some 70 km north of the city of Takoradi, and 10 kilometres south-west of Tarkwa.
The Mantraim central project known as "Mantraim Central" is a part of the main Mantraim project which has been drilled extensively to grade control. It is the main target area of the project under study, the objective of which is to evaluate the ore resource of the central portion of the Mantraim project based on the 50 m x 50 m drill spacing to determine if the prospect has been underestimated or overestimated and the possibility of continuity of the ore deposit at deeper depth. The ore body strikes virtually north – south and dips 10 – 180 E. Using the ordinary kriging methodology, a total of 486,119 gold ounces of indicated resource covering 15 million tonnes of oxide ore material at an average grade of 1.02 g/t Au was realised from the model. Ordinary kriging was used to define the mineral resources of the deposit due to the nature and the amount of data that were available for estimation in the project area. To verify this, first a kriging estimate of the local mean was set up, and then a simple kriging estimator using this kriged mean was performed.
The drilling of the prospects of the concession has provided a total of approximately 13,721 gold assay intervals emanating from 398 RC holes covering an area of 575 m of strike length and 400 m in width. The generated ore model resulting from the modelling of the mineralised grade intercepts within the central main zone constitutes an 11,297 assay samples from 390 drill holes. Gold mineralisation has been constrained by the development of wireframes modelled at a 0.3 g/t Au lower cut-off grade at an average dip of 10o E. Variography was completed on the 1 m composite for the modelled grade shell Based on the findings, it is being recommended that the southern part of the model which was not covered by drilling data should be covered with 25 m x 25 m drilling to help establish further the model continuity. It is also being recommended that systematic deep holes be drilled over the property to ascertain the continuity or otherwise of the model.
Description
Thesis (MSc)
Keywords
Gold Mining, Mining Leases, Mineral Resource, Ghana