Geology of volcanogenic massive sulfide deposit near Meli, northwestern Tigray, northern Ethiopia

S Abraham,S Gebreselassie,B Konka

doi:10.4314/mejs.v7i1.117239

Abstract

Results of a preliminary study conducted on the volcanogenic massive sulfide (VMS) deposit near Meli/Rahwa, northern Ethiopia are presented in the paper. The study area forms part of Neoproterozoic basement of northern Ethiopia and southern part of the Arabian Nubian Shield (ANS). Selected surface rock samples of different lithologies and core samples from five boreholes were analyzed for petrography and geochemistry. The area consists of matabasalt, meta-andesite and meta-rhyolite, meta-volcaniclastics, phyllite and post-tectonic granite. The rocks have experienced low grade metamorphic conditions. Base metal mineralization, VMS- type, is present and consists of pyrite, chalcopyrite, sphalerite and galena. Chloritization is the dominant alteration among others, and the ore body is associated with mafic to intermediate metavolcanic and metavolcaniclastic rocks and follows the same trend with the host rocks, striking north-south with subvertical dips. The mineralization is about 50-70m long, 15-20m thick and rich in copper and zinc (above 5%) and Au as a byproduct which is in minable amount in the VMS-related gossan. The deposit is related to bimodal volcanic condition and is produced in an island arc tectonic setting.Keywords: VMS, Base metals, Auriferous gossan, Meli/Rahwa, Tigray, Northern Ethiopia.

Highlights

Ethiopia is one of the northeastern African countries encouraging mineral exploration activities in a big way in recent times
Petrography of the country rocks Among different lithologies present in the area, the rock types associated with mineralization are mainly mafic-intermediate metavolcanic rock (MMV) and intermediate metavolcaniclastics (IMVC)
Meli area consists of Neoproterozoic basement rocks, matabasalt, metaandesite and metarhyolite metavolcaniclastic and phyllite and intruded by post-tectonic granite

Summary

Introduction

Ethiopia is one of the northeastern African countries encouraging mineral exploration activities in a big way in recent times This is visible since the last one decade or so. Gold and base metal sulfides are attracting the attention of many exploration companies like, National Mining Company, Ezana Mining Plc, Sheba Mineral Exploration Company, Donia Mineral Exploration Company, Harvest Mineral Exploration Company etc. Their efforts have resulted in delineation of many potential areas in Neoproterozoic basement for detailed exploration and drilling in different parts of the country.

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Results

Discussion

Conclusion