## 4 Discussions  
The processing of the geophysical and ASTER data used in the present work is a preliminary step of great importance for recognizing new potential targets for mining research at the scale of the Kelaat M'Gouna inlier. The combination of two different data types allowed us to map in detail the hydrothermal alteration zones associated with the  
Figure 6: Mineral prospectivity maps: (**a**) mineral prospectivity map derived from natural gamma spectrometry data. (**b**) Mineral prospectivity map derived from ASTER image. metal deposits, especially the gold deposits. [PERSON] et al., 2008 [31], showed that the three gold prospects in the study area are associated with hydrothermal alteration phenomena. According to these authors, silicification is expressed either by developing quartz stockworks or by dispersion in the host volcano-sedimentary formations, following a general NE-SW direction. Generally, this silicification is accompanied locally by opening zones filled with potassium feldspar and tourmaline. In this respect, ratios of K/eTh and K/eU were calculated to highlight enrichment zones in this element. Chloritization is manifested by the development of large zones in the soft greenish levels of the volcano-sedimentary series. For this purpose, the Aster image band ratio (b7 + b9)/b8 was calculated to map the spatial distribution of high chlorite content zones. Hematization is materialized by the development of iron oxides and hydroxides, following the fracturing planes, which are generally oriented N20\({}^{\circ}\). This type of alteration mineral was mapped using the band ratio (b5/b3) + (b1/b2). Finally, the band ratio (b5 + b7)/b6 was used to map the sericitization in the study area in a subordinate manner [31]. In the form of thematic layers, this database was fuzzified by the fuzzy logic modelling technique by combining the two mineral prospectivity maps, Aster and radiometric. Subsequently, a mineral prospectivity map for the study area was generated. A total of seven prospective value areas were identified (Figure 7), and they are mainly associated with alteration zones:  
* Area 1 is mainly associated with alteration zones in the Ouarzazate Group rhyolitic formations. This elongated area straddles a system of NE-SW and NNNE-SSW faults. These faults probably served as flow paths for hydrothermal mineralization. The documented mineral occurrences also show a close spatial relationship with the fault systems in the study area, particularly in the Tagmout copper deposit. * Area 2 and 3 are located at the contact zone between the pink granite of Isk n'Alla and the volcanic and rhyodacite formations of the Lower Ouarzazate Group. These formations are crossed by a swarm of rhyolitic dikes of variable direction of the Upper Ouarzazate Group. At outcrop, both zones host some Cu, Mn and Fe showings. * Area 4 stakes the ENE-WSW Sidi Flah fault zone, which extends over several kilometers. From a mining point of view, several showings, including Au, Cu, Pb and Mn, have been reported along and near this fault. This type of fault may favor the circulation of mineralizing hydrothermal fluids from a deep source that may enrich the host rocks and tectonic structures [22; 23]. * Area 5 coincides with hydrothermal alteration associated with the Wawitcht granite and volcanic rocks of the Lower Ouarzazate Group. * Area 6 is associated with the Cryogenian basement formations or its Ediacaran cover. Minerally, it is a prospective area as it hosts three gold prospects. According to [PERSON] et al., 2008 [31]; [PERSON] et al., 2018 [32], most gold mineralization in the study area is restricted to Precambrian formations such as Cryogenian basement turbid volcano-sedimentary and Ediacaran granites. This indicates that gold prospecting in the areas adjacent to the three indicated prospects is likely to be most successful in the altered zones recognized in basement rocks and its Ediacaran cover.