The Cu-Ag-Pb Polymetallic Mineralization of Agdim-Ait Elfersi Sector, North-Eastern Part of the Saghro Massif, Morocco: Geological Setting, Ore Petrography and Geochemistry

Lahcen Ousaid,Zineb Aafir,Hassan Admou,Aziza Lamchaimech,Said Courba,El Moustafa Mouguina,Youssef Hahou,Khadija Diani,Rachid Ziadi

doi:10.46717/igj.55.1a.1ms-2022-01-20

Lahcen Ousaid, Zineb Aafir + Show 7 more

Open Access

https://doi.org/10.46717/igj.55.1a.1ms-2022-01-20

Copy DOI

Abstract

The Cu-Ag-Pb polymetallic mineralization of the Agdim-Ait Elfersi sector is situated in the eastern Anti Atlas Moroccan belt, the northeastern part of the Saghro inlier. The mineralization is hosted in the volcanic rocks of late Neoproterozoic and the detrital sedimentary rocks of the Lower Cambrian. A network of faults has affected this area; it is a brutalizing deformation with NW-SE, NE-SW, E-W, and NNE-SSW directions. NW-SE and NE-SW structures have a metallogenic significance. This tectonic canvas was used as a target of a mineralization vein with Cu, Ag, and Pb in this area. By combining geological, structural, and metallogenic characteristics, it can be assumed that the Cu-Ag-Pb mineralization of the Agdim-Ait Elfersi sector is linked to two major events. A late Pan-African event linked to the extensional tectonics of the late Neoproterozoic, responsible for the establishment of mineralization at the level of the basement, and then a late Hercynian-Atlasic event, which manifests by the remobilization of metals in NE-SW oriented structures. Geochemical analysis shows the polymetallic character of this mineralization. The high contents of silver and mercury observed indicate the presence of similarities of an Ag-Hg epithermal type of mineralization in this area. Geological context, as well as mineralogical and textural characters of the Agdim-Ait Elfersi sector are reminiscent of epithermal-type mineralization as in the Imiter and Zgounder deposit.

Highlights

The Moroccan Anti-Atlas is a vast metallogenic province (Fig. 1-b) that contains numerous deposits and showings of base and precious metals known for more than long years ago
The previous work and geological studies that had been carried out on this transition zone between the Late Neopoterozoic and the Lower Cambrian in the Saghro inlier, in its northeastern part, are very limited. These studies have emphasized the importance of felsic volcanism generated by this extensional late Neoproterozoic tectonic, in relation to the deposition of the silver mineralization, but they overlook the effect of the Hercynian and Alpine orogeny on the Pan-African structures, knowing that the fault axes that affected the Precambrian basement are continuous in the Paleozoic cover
The current study aims to characterize the Cu-Ag-Pb polymetallic mineralization of the Agdim Ait Elfersi sector, on one hand, by combining geological setting, ore petrography, and geochemistry data; on the other hand by trying to emphasize the role of the Hercynian and Alpine orogenesis on the establishing of mineralization in the transition zone between late Neoproterozoic and Lower Cambrian, northeast of the Saghro massif

Summary

Introduction

The Moroccan Anti-Atlas is a vast metallogenic province (Fig. 1-b) that contains numerous deposits and showings of base and precious metals known for more than long years ago. The Anti-Atlas underwent an extensional tectonic phase at the end of the late Neoproterozoic; it is responsible for the establishment of significant volcanic activity, materialized by the acidic and basic volcanic flows, which form the Ouarzazate group This magmatic activity has a very interesting effect on the transfer of elements from the mantle to the surface. The previous work and geological studies that had been carried out on this transition zone between the Late Neopoterozoic and the Lower Cambrian in the Saghro inlier, in its northeastern part, are very limited These studies have emphasized the importance of felsic volcanism generated by this extensional late Neoproterozoic tectonic, in relation to the deposition of the silver mineralization, but they overlook the effect of the Hercynian and Alpine orogeny on the Pan-African structures, knowing that the fault axes that affected the Precambrian basement are continuous in the Paleozoic cover. The debate on the saghro ore deposits (Levresse et al, 2004; Tuduri et al, 2006, 2018; Diallo et al, 2021) are for the most part Ediacaran in age and magmatic-hydrothermal related, this discussion meet in a point of the connection and association of magmatic-hydrothermal fluids in the formation of mineralizing events

Methods

Results

Discussion

Conclusion