Exploration and Mapping of Metalliferous Black Shales in the Saghro Temporary Subsidence Zones (Anti-Atlas, Morocco)  

作　　者：Ali Bouayachi Saida Alikouss Zouhir Baroudi Youssef Zerhouni Lahcen Rakhis Mohammed Zouhair Assia Idrissi Mourad Essalhi Barzouk Abdelhafed Ali Bouayachi;Saida Alikouss;Zouhir Baroudi;Youssef Zerhouni;Lahcen Rakhis;Mohammed Zouhair;Assia Idrissi;Mourad Essalhi;Barzouk Abdelhafed(Department of Geology, Faculty of Sciences Ben M’Sik, University Hassan II, Casablanca, Morocco;MANAGEM Group, 191, bd Med Zerktouni, Twin Center Tour A. 20100, Casablanca, Morocco;Department of Geology, Faculty of Sciences, University Mohamed V, Rabat, Morocco;Faculty of Sciences and Techniques, University Molay Ismail, Errachidia, Morocco;Faculty of Sciences Semlalia, Caddi Ayyad University, Marrakech, Morocco)

机构地区：[1]Department of Geology, Faculty of Sciences Ben M’Sik, University Hassan II, Casablanca, Morocco [2]MANAGEM Group, 191, bd Med Zerktouni, Twin Center Tour A. 20100, Casablanca, Morocco [3]Department of Geology, Faculty of Sciences, University Mohamed V, Rabat, Morocco [4]Faculty of Sciences and Techniques, University Molay Ismail, Errachidia, Morocco [5]Faculty of Sciences Semlalia, Caddi Ayyad University, Marrakech, Morocco

出　　处：《Open Journal of Geology》2023年第7期740-762,共23页地质学期刊（英文）

摘　　要：The Saghro massif constitutes a vast metallogenic province with numerous deposits and shows of base metals (lead, zinc, copper) and precious metals (gold and silver), besides various useful substances (talc, pyrophyllite, barite, fluorite). Silver/lead occurrences are concentrated along the Cryogenian Imiter series and moderately at Boumalne and Sidi Flah. Copper occupies the plutonic intrusions and intrusive rocks of the East-Central Saghro while barite deposits are widespread throughout the Cambrian cover of the East Saghro in contact with the Ediacaran basement. To justify this distribution, the new contributions of the cartography and the organic geochemistry of the black shales of Jbel Saghro have clearly shown the particularity of the Imiter black shales in terms of the richness in organic matter (TOC = 0.18%), the blackish color and the friability. The Boumalne and Sidi Flah groups present some similarities with the Imiter group, such as the sub-equatorial structuring, the friable pelites and the richness in organic matter (Boumalne TOC = 0.11% and SidiFlah TOC = 0.16%), which is a quite good show that requires to reinforce the exploration works. For Western Saghro in the Iknioun and Qalaa’t M’Gouna groups, the variations in the thickness of the volcanic cover show an irregular paleotopography with hard, greenish, organic-poor pelitic sediments (TOC = 0.01 to 0.04%). We can conclude that the formation of Imiter-type silver concentrations requires the combination of the sedimentological, the volcanic and structural factors. For Imiter-type silver these factors are: a fine pelitic and argillic casing deposited in a confined environment, a basic volcanism source of metals and other intermediate to acid generated by the hydrothermalism and heat, a convenable paleotopography and a network of fracturations to trap the mineralizations.The Saghro massif constitutes a vast metallogenic province with numerous deposits and shows of base metals (lead, zinc, copper) and precious metals (gold and silver), besides various useful substances (talc, pyrophyllite, barite, fluorite). Silver/lead occurrences are concentrated along the Cryogenian Imiter series and moderately at Boumalne and Sidi Flah. Copper occupies the plutonic intrusions and intrusive rocks of the East-Central Saghro while barite deposits are widespread throughout the Cambrian cover of the East Saghro in contact with the Ediacaran basement. To justify this distribution, the new contributions of the cartography and the organic geochemistry of the black shales of Jbel Saghro have clearly shown the particularity of the Imiter black shales in terms of the richness in organic matter (TOC = 0.18%), the blackish color and the friability. The Boumalne and Sidi Flah groups present some similarities with the Imiter group, such as the sub-equatorial structuring, the friable pelites and the richness in organic matter (Boumalne TOC = 0.11% and SidiFlah TOC = 0.16%), which is a quite good show that requires to reinforce the exploration works. For Western Saghro in the Iknioun and Qalaa’t M’Gouna groups, the variations in the thickness of the volcanic cover show an irregular paleotopography with hard, greenish, organic-poor pelitic sediments (TOC = 0.01 to 0.04%). We can conclude that the formation of Imiter-type silver concentrations requires the combination of the sedimentological, the volcanic and structural factors. For Imiter-type silver these factors are: a fine pelitic and argillic casing deposited in a confined environment, a basic volcanism source of metals and other intermediate to acid generated by the hydrothermalism and heat, a convenable paleotopography and a network of fracturations to trap the mineralizations.

关 键 词：Saghro Metallic Shales Silver TOC EXPLORATION Cryogenic POLYMETALLIC Imiter 

分 类 号：F42[经济管理—产业经济]