Origin of the Moroccan Touissit-Bou Beker and Jbel Bou Dahar Supergene Non-Sulfide Biomineralization and Its Relevance to Microbiological Activity, Late Miocene Uplift and Climate Changes

Through integration of Pb-Zn ± Cu non-sulfide mineralogy, texture, and stable isotope (C, O, S) geochemistry, the world-class Touissit- Bou Beker Jbel Dahar Mississippi Valley-type districts Moroccan Atlasic system have been investigated in order to gain insights into origin processes that contributed formation base metal mineralization. In both districts, direct replacement (“red calamine”) wallrock (“white ores are observed. Based on mineral assemblages, ore textures, crosscutting relations, three distinct mineralizing stages recognized. The earliest, pre-non-sulfide gossanous stage was a prerequisite for following supergene constituted driving force ultimately promoted leaching most metals such as Zn alkalis from their rock sources. two stages, referred main “red calamine” late “white generated bulk mineable “calamine” Touissit-Bou districts. Stable compositions (?13CV-PDB, ?18OV-SMOW, ?34SCDT) support three-stage model whereby were released by acidic fluids then precipitated bacteria archaea-mediated metal-rich meteoric due decrease temperature and/or increase fO2. Oxygen thermometry indicates decreasing precipitation temperatures with advancing paragenetic sequence 33° 18 °C, wet semi-arid arid climatic conditions. close spatial relationships between coexisting sulfide mineralization along constraints suggest oxidation sulfides occurred concurrently after Alpine orogeny 15 Ma present. More importantly, current data show first time involvement biologically controlled activity major process triggered deposition at Conclusions drawn this study therefore implications (MVT) -derived deposits worldwide account prominent role biological genesis category deposits.