MINERAL EXPLORATION IN THE VICINITY OF THE LATE EDIACARAN BOUTEGLIMTAPLITE AND PEGMATITE DIKES INIMITER INLIER USING ASTER DATA: PRELIMINARY RESULTS

Abstract

In the southern part of the Imiter inlier, the early Ediacaran basement of the Saghro Group is crosscut by an important swarm of aplitic and pegmatitic dikes that display an extension of several meters and which can exceed 10 in thickness. They are distributed according to two main directions: NE-SW and NW-SE. Petrographic analysis reveals that the pegmatites and aplite primarily consist of quartz, plagioclase, K-feldspar, muscovite, biotite, allanite, and sphene. The BouTeglimt pegmatites, related to the large BouTeglimt granitic and granodioritic plutons, are exterior pegmatites type, hosted in the metamorphic country rocks. Pegmatite zoning is recognized at two scales: internal zoning, representing variations in mineralogy and texture within individual pegmatite bodies, and regional zoning, characterized by increased mineralogical complexity with distance from the granitic source. Using the ASTER sensor, the study investigated significant clayey, phyllitic, and propylitic alterations of the pegmatites, aplite, and their host rocks in the Imiter mine area. Field investigations and mineralogical characterization highlight four new mineralized zones in base and precious metals. These zones are commonly situated at the peripheries of granites or at the contact between the SG series and the late Ediacaran rocks of the Ouarzazate Group. The mineralization is observed in steeply-dipping veins along major E-W faults parallel to the Imiter fault, as well as in stockwork ore within tuffs, lapilli tuff, rhyolite, and disseminated mineralization within various Ouarzazate Group pyroclastic rocks. The ore mineralogy comprises sulfides and oxide minerals. Furthermore, the muscovite-rich BouTeglimt pegmatite and aplite can be considered an excellent exploration indicators due to their occurrence in fertile granites and rare-element pegmatites. They may hold potential as indicators of tantalum mineralization.