Projects

The San Juan property lies approximately 450 km southeast of Ensenada and 26 km south-southwest of the fishing and tourist community of Bahia de los Angeles.  The historic cultural centre of the Jesuit Misión San Borja, established in 1762, is located 15 km to the west of the property and served as a focus for the early exploration; many of the artesanal workings in the area date from that time.

The San Juan mine at the centre of the property operated until 1911.  The main deposit was worked on eleven levels; numerous shallow adits and exploration shafts are located peripheral to the main mine. Mexican government documentation indicates that 24,611 tons grading 3.22 g/T Au and 364.47 g/T Ag were mined; mine openings examined during the site visit suggest that the recovered tonnage might be significantly greater.

The property is underlain by intrusive and metamorphic basement rocks of Cretaceous age. These are overlain in the west of the property by a Tertiary sequence of volcanic rocks.  Mineral occurrences discovered to date on the property are all hosted by the Cretaceous assemblage.  Mina San Juan and a large alteration zone in the northern part of the property are hosted by a biotite ± hornblende granite with K-feldspar megacrystic phases.  The granite is cut by a west-northwest trending, altered fracture set.  Undeformed, fine-grained felsic dykes, also with rare K-feldspar megacrysts, intrude the main San Juan Granite along this structural strike.  The dykes contain disseminated pyrite and arsenopyrite and are interpreted as being roughly contemporaneous with mineralization. 

The mineralization throughout this large property is remarkably similar in style.  It comprises shear-hosted quartz veins or breccias with or without the sulphide minerals pyrite, arsenopyrite, galena and sphalerite and (very minor) chalcopyrite.  Even bull quartz veins contain elevated levels of silver, arsenic, lead and zinc and, at several locations sampled, antimony and bismuth values are erratic but also elevated. 

Every chip sample taken from vein material on the San Juan property has returned a value of greater than 1 gm/t gold; the median value is roughly 4 gm/t.  These results are consistent with and on a larger scale than previous observations.  The mineralising event is interpreted as intrusion-related, with the geochemical style resembling a gold-bearing porphyry system, associated with a quartz-rich peraluminous granite.  Some of this gold-bearing mineralization has been concentrated along fractures as vein deposits such as that at Mina San Juan. 

The mineralising system for these deposits was large.  The intrusive and metamorphic assemblage mineralised by this event effectively underlies most of the property and probably extends beneath the Cainozoic cover to the west.  Little of this ground has been explored beyond prospecting and none of this exploration is recent.  The property hosted a commercially producing mine.