Geology and geochemistry of the Ixtahuacan antimony-tungsten deposits, northwestern Guatemala

he Ixtahuacan Sb-W deposits are hosted by the upper Pennsylvanian to Permian Tactic formation of the central Cordillera of Guatemala. The deposits consist of disseminated gold-bearing arsenopyrite, and stibnite in stratabound lenses, in quartz-ankerite veins and breccias, and as disseminations in pyritiferous black shale and sandstone units. Scheelite is found as disseminated crystals and in veinlets in limestone.;An excellent correlation of As with S and a negative correlation of Na with Sb and As in shales and sandstones in the Los Lirios mine suggest sulphidation of the ore fluid and leaching of Na during the mineralizing event.;Microthermometric measurements performed on inclusions in quartz and scheelite point to a low temperature (160 to 190;The Ixtahuacan deposits are interpreted to have formed at a low temperature probably at a depth of a few hundred metres from a fluid with intermediate pH and under relatively low...