Subsurface linear structures and potential zones of mineralisation of the Iramba-Sekenke greenstone belt, central Tanzania with implications for the structural-controlled mineralisation

Abstract

This study aims to delineate concealed subsurface linear structures and their relationship with mineralisation in the Iramba-Sekenke greenstone belts. Results reveal three different types of linear structures and their continuations concealed, which were previously not identified. These structures include dykes trending in NE-SW and NS; shear zones with NW-SE trending and faults that trend in NE-SW, NW-SE and N-S. The faults and shear zones, which were previously shown to terminate at the northwestern end of the Iramba Plateau due to sediment cover, have been revealed to continue into Wembere depression. Moreover, the aeromagnetic and gravity results show that some faults are intruded by dykes in the same trends, which were not previously identified. The geological relationship between these linear structures shows that the youngest structures are the western dolerite dyke trending N-S and the oldest is the NE-SW Wembere-Iramba Plateau fault. The delineation of geological structures from magnetic and gravity data using different analysis techniques reveals that the mining pits are located close to geological structures trending in NW-SE, NE-SW and N-S directions. The integration of the findings from CET grid analysis techniques, together with magnetic maps and geological information reveals a good correlation between known occurrences of minerals and promising exploration target areas. The good correlation between the artisanal mining pits with the location of the potential exploration targets is consistent with the location of lineaments and provides future promising prospects for mineral exploration. The correlation suggests that mineralisation and ore deposits in the study area are respectively structurally controlled and hosted in deformed rocks. This study is potentially useful as a guide for the delineation of concealed subsurface linear structures and integration of structural geometry and geophysical methods for exploration of hidden mineral deposits in the Iramba-Sekenke greenstone belt.