grains in Mask Cave tempers (Table 5).
This zone consists of both a calc-silicate skarn system as well as chalcedonic
and quartz veining with arsenopyrite and pyrhhotite in coarse clastic sediments.
Gypsum has also been found in dikes as platy masses up to 5 cm across; as aggregates, several centimeters across, of sharp, colorless, tabular crystals up to 1 cm long in cavities associated with analcime and celestine; and as colorless veins associated with pyrite, dolomite and chalcedonic
03 opt; whereas drill hole MS-2 hit a 40-foot thick zone of chalcedonic
veining at 160-200 feet, which ran 0.
quartz has also been observed as gray to white cryptocrystalline veins.
Veins associated with higher gold values, (greater than 1 g/t Au), generally consist of fine grained or chalcedonic
quartz with weak to moderate banding.
Quartz occurs as tiny vein-filling crystals, crystalline aggregates and chalcedonic
Large boulders up to 5m in width of silicified conglomerate with chalcedonic
, banded and crackle brecciated epithermal quartz with fine pyrite were initially identified in a small stream and traced back to outcrops.
Its color is brownish to yellowish and it commonly contains thin veinlets of gray chalcedonic
Mapping and sampling has recently identified epithermal chalcedonic
quartz in a parallel zone 150m to the west within the adjacent conglomerate
Supergene or late-stage hydrothermal quartz also forms yellowish to pale blue micro-botryoidal chalcedonic
crusts on sphalerite from Cerro Chico.
Referred to as the Guabisay prospect, this prospect consists of a shallowly dipping, 3 to 10 m wide band of argillic alteration enclosing a core of chalcedonic
silica and brecciation.
The mineralization was characterized by (i) pervasive drusy quartz fracture coatings and fillings with abundant fine veinlets of chalcedonic
and crystalline quartz and (ii) anomalous values in Ag, As, Sb and Hg; all indicative of epithermal gold mineralization.
A secondary cap of chalcedonic
silica covers the entire mega-breccia body.
Here silicification occurs as a broad zone of silica flooding that is cored by a central zone of chalcedonic
silica stockwork with an overall northeast trend.