Properties | Baluarte 43-101
Geological Setting
Regional Geological and Structural Setting
Location and access to Baluarte Au-Ag epithermal prospect, Sinaloa and Durango states, Mexico.
The Baluarte Property is situated on the western flank of the Sierra Madre Occidental geological Province. The Mid-Tertiary Sierra Madre Occidental (“SMO”) is the largest silicic igneous province in North America (Mcdowell and Claybaugh, 1979 and Ward, 1995). It is 200-500 km wide and extends for more than 2000 km south from the US-Mexico border to its intersection with the Trans-Mexican Volcanic Belt.
The La Campana Showing
Situated on the left bank of the Baluarte River, in the Durango state, the La Campana showing is less than 130 m due east from the sandy bank of the river and can be easily be accessed by a dirt path running parallel to it. The principal adit is found about 850 m on strike in direction 10° from the Santa Rita showing. The La Campana showing consists of a 1 km long structure oriented 255º dipping 75º to the NW. The main showing exposes a strongly altered Au and Ag mineralized breccia previously mined along a 20 m deep X 40 m high adit that reaches the top of a small hill. The entrance to the adit is roughly 4 meters wide and leads to exposures of brecciated andesitic rocks that show extensive sign of hematization and silicification, with subordinate epidotization. The altered angular to sub-angular andesitic fragments vary from mm to m in size. An extensive network of quartz veins and veinlets crisscross the adit wall and probably constitute the cement and matrix. The quartz veins are banded showing alternating whitish to brownish layers. The center of the quartz veins are commonly vugged and filled by well-formed quartz and calcite crystals. As we recede from the main brecciated and mineralized zone, the alteration is less pronounced and the network of quartz veins and the network of quartz veins and veinlets becomes less dense and more scattered exposing a grey plagioclase porphyritic andesite. The La Campana site also reveals some exposures of andesitic tuff breccias and agglomerates.
We can observe the continuity of the La Campana mineralized structure 200 m toward the west on the right bank of the Baluarte River and further 500 m inland along strike where we unearthed a series of quartz-rich veins. One of the exposed veins is 3 m in width and oriented 265º/65º. We noticed the intense silicification present at the La Campana showing with some chlorite and epidote present but no Fe-oxide. On the east side of the main adit 130 m along strike, we have discovered a 3 m thick silicified zone on top of a 30 m hill where scattered mineralized rubble litters the floor (e.g. the Santa Nino tailings).
Geochemical analyses
La Campana Showing
Significant Au and Ag values were obtained from the walls and pillar from the La Campana adit (0.16-16.7 Au (g/t) and 9-626 Ag (g/t)) as well as from the top of the hill where the adit breaks through (41.7 Au (g/t) and 704 Ag (g/t)). The entire La Campana structure extending for 1 km yielded lower Au and Ag average values since the channel samples collected from the presumed western extension of the La Campana quartz breccias display low Au and Ag contents (0.11 g/t and 2 g/t respectively; n=13). Overall, the 22 collected samples produced averages of 3.37±9.37 g/t Au (1sd) and 89±202 g/t Ag respectively.