Application of Geophysics for Quick Determination of Deposit in Mineral Exploration - A Case Study

Abstract

The Balatindi Mineral Prospect, Guinea, is a multi-element mineral prospect that hosts commercial quantities of gold, uranium and copper. A major challenge for exploration activities within the area is the turnaround time for assay results due to the unavailability of a nearby assay laboratory and the high cost of analysis. This therefore delays assay results which are needed for quick decisions during field work. There is therefore the need to find a faster and cheaper way of delineating mineral anomalies. Magnetic and radiometric geophysical techniques were considered because of the rapid and cost-effective ways in which data is acquired and they yield substantial quantity of accurate data enhancing interpretation and deduction. Down hole drill data for 37 HQ size diamond drilled holes of about 9200 m were used for the analysis. Magnetic susceptibility data were secured from 24 drill hole data for the Central Polymetallic Prospect  area, whiles radiometric data were taken for the 23 drill holes in the other areas. The data were correlated with the laboratory assay results for gold and uranium respectively.  Strip logs and statistical analysis were used to interpret magnetic susceptibility readings against gold assay values, and radiometric readings against uranium assay values. Maximum and minimum values of -2.46 × 10^-3 and 546.5 × 10^-3 magnetic susceptibility were respectively recorded whiles 45 cps and 7250 cps were the maximum and minimum radiometric readings obtained. Magnetic susceptibility values did not show any preferential correlation with gold mineralisation.  Radiometric cps values showed a very strong direct correlation with uranium mineralisation. This is because the radiometric cps is a function of the radiometric mineral present and therefore, radiometric survey can be used as a faster and cost-effective way of delineating uranium anomaly within the Balatindi prospect.

Keywords: Balatindi, Magnetic susceptibility, Radiometric count, Multi-element mineral deposit.

DOI: 10.7176/JNSR/11-18-04

Publication date:September 30^th 2020