Hydrothermal gold mineralization and structural controls near May Hibey, Northwestern Tigray, Northern Ethiopia

Mickiale Giday,Bheemalingeswara Konka

doi:10.4314/mejs.v9i2.3

Abstract

Ezana Mining Development Company has recently reported presence of gold mineralization near May Hibey area, western Tigray, northern Ethiopia. It is in association with hydrothermal quartz veins within the Neoproterozoic low grade basement rocks, metavolcanics and metasedimentary rocks. Structural data suggests four phases of deformations and NE-SW trending foliation is the prominent one among others. Among different generations of veins, NNE, NS and NNW trending third generation quartz veins are gold-bearing and presence of a narrow shear zone with dextral sense of movement trending NW-SE is significant interms of mineralization. Hydrothermal alterations are dominated by chloritization and sericitization. Core samples from shear zone within the sericite-quartz schist and quartz porphyry rocks shows presence of pyrite, pyrrhotite, sphalerite, chalcopyrite, galena and gold in decreasing order of abundance. Gold mineralization is closely associated with the sericite and carbonization alteration zone. Based on mineral association, alteration, deformation, texture, and paragenetic scheme, it is suggested that the mineralization is a syn-orogenic variety formed in an island arc tectonic setting.Keywords: Quartz veins, Shear zones, Gold, Petrography, Geochemistry, MayHibey, Ethiopia.

Highlights

Ethiopia is endowed with various types of metallic and non-metallic mineral resources such as gold, platinum, copper, lead, zinc, tantalite-columbite, manganese, molybdenum and potash (Aspermont, 2011)
This study provides an insight into the geology of northern Ethiopia based on geochemistry of the low grade metavolcanic rocks from the PanAfrican Axum area
May Hibey area forms a part of Neoproterozoic stratigraphy of northern Ethiopia and comprises of metavolcanics, metavolcaniclastics, metasediments and intrusive syn-tectonic granites

Summary

Introduction

Ethiopia is endowed with various types of metallic and non-metallic mineral resources such as gold, platinum, copper, lead, zinc, tantalite-columbite, manganese, molybdenum and potash (Aspermont, 2011). Increased mineral exploration activities for the last two decades due to the initiatives taken by the government, has resulted in locating many metallic and non-metallic deposits in different parts of the country (Tadesse, 2009; Getaneh and Tadesse, 2015). Major focus of several mining companies and researchers has been the gold and base metal deposits, occurring in low grade basement rocks of Neoproterozoic age. Gold occurrences are reported from southern, western and northern parts of the country but base metals, volcanogenic massive sulfide (VMS). Type (some are gold-bearing) are mainly reported in northern Ethiopia (Bheemalingeswara and Atakilty, 2012; Samuel et al, 2015). All the reported gold deposits are in the advanced stage of exploration, not reached exploitation stage except 1) Legadembi gold mine in southern Ethiopia

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