Ricardo Valls

The Geology and Mineral Resources of Northern Haiti. Ricardo Valls

The geology of Northern Haiti corresponds to a volcanic arc of Meso-Cenozoic Age that can be traced from Central Cuba, through the Dominican Republic and forms part of the mountains of the Massif du Nord group oriented NW-SE. This group is composed mainly by volcanic tuffs and lavas from the volcanic belt, ranging in composition from felsic, through intermediate, to mafic and ultramafic rocks. The belt is composed of numerous lenticular bodies of lavas and pyroclastic material of felsic composition, varying from dacite to rhyolite, embedded in a thick series of predominant mafic volcanoclastic rocks, mainly andesite with lesser amounts of basalts, with numerous intercalations of diverse sedimentary rocks, like radiolarians cherts, carbonate rocks, and tuffs. Copper and gold are the two main ore types in the area. Copper is usually found associated with the porphyritic facies, the apophyses microtonalitics, and the silicified zones, filling fissures and fractures, as well as disseminated. Within the quartz vein systems, the copper is contained in the chalcopyrite, while the gold appears both as native gold and as a very fine disseminated gold in the sulphide zone. It can also form spectacular concentrations on the oxidised cap.