Peri-granitic hydrothermal circulations and mineralization. 3D/4D Coupled Numerical Modeling, applications in the Mining District of Tighza (Central Morocco).

      Аннотация: The objective of our research is to simulate numerically hydrothermal regimes and mineralization probability (R?AI) around plutons. The first results come from simulations of some natural cases: i) Fluid flow and mineralization patterns are strongly dependent of the emplacement depth of plutons. ii) The pluton floor zone is not favorable for mineral deposition; iii) The apexes strongly modified the fluid flow and mineralization patterns; iv) The cooling phase is not the main phase of convection. Zones of ore deposits may also occur before and during the hottest phase; v) Extensional detachments faults are able to delocalize and modify fluid flows. The second results concern Tighza ore deposits. The results are: i) the probable zone of mineralization appears at the beginning of magma emplacement within the permeable zone and extends to cover the area around pluton; ii) During the cooling phase, the probable zone was reduced and restricted in the permeable zone (W1) during 0.6 Myr of cooling; iii) Application of isotopic closure temperature concept with R?AI shows that the cooling ages between mineralization in W1 veins and the intrusion are not separated by more than 0.10 Myr.

Ключевые слова: coupled numerical modeling, hydrothermal fluid flow, intrusion-related ore deposits, W-Au mineralization of Tighza (Jebel Aouam, morocco), gravimetry data, 3D modeling, Rock alteration index.