soulaimani, saâd université ibn tofail - faculté des sciences - laboratoire géosciences des ressources naturelles, Maroc , manar, ahmed ministère de l’energie, des mines, de l’eau et de l’environnement, Maroc , chakiri, saïd université ibn tofail - faculté des sciences - laboratoire géosciences des ressources naturelles, Maroc , allouza, mohamed université ibn tofail - faculté des sciences - laboratoire géosciences des ressources naturelles, Maroc , ezzayani, jamil université ibn tofail - faculté des sciences - laboratoire géosciences des ressources naturelles, Maroc , el hmidi, fatima université ibn tofail - faculté des sciences - laboratoire géosciences des ressources naturelles, Maroc , nouaim, wafae université ibn tofail - faculté des sciences - laboratoire géosciences des ressources naturelles, Maroc

3D modeling and reserves estimation using gravity data of Hajjar central orebody (Marrakech region, Morocco)

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The Hajjar orebody is one of the most important polymetallic (Zn+Pb+Cu) deposits in Morocco. It is considered as a typical example to estimate mineral resource and to develop orebody modelling. Due to its remarkable physics properties (density and susceptibility), the deposit permits to validate geophysical models for mining prospection. The aim of this work is to better estimate the Hajjar orebody resource in a 3D model using gravimetric data. We use Geosoft oasis montaj and GM-SYS to process the gravity data, provided by Geophysical survey of Ministry of Energy, Mines and Sustainable Development. A near-real morphology of the ore clusters is issued from interpolation between 9 2¾-D profiles in order to calculate the 3D model. The obtained 3D models allowed us to estimate the resource of Hajjar central orebody (20 MT). The comparison with the deposit geostatistical model led to validate our 3D model. The error has not exceeded the threshold of 20%. Given that, this modelling approach allows the orientation of reconnaissance works and thus reducing exploration costs.

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Hajjar mine , Morocco , gravimetry , numerical modelling , 2¾ , Dmodel , 3D model , reserve estimation

bulletin de l’institut scientifique, section sciences de la terre

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