Eastern Borosi Gold-Silver Blag Gold-silver Vein System
The Blag Gold-Silver Vein System is located three kilometres east of the Guapinol – La Sorpresa Trend and drilling of five holes in 2014 by Calibre was successful in outlining high grade gold-silver mineralization including; 6.73 metres @ 4.11 g/t Gold and 235.9 g/t Silver. Follow-up drilling in 2015 further extended the high grade zone including 10.74 metres @ 3.08 g/t Gold and 381.3 g/t Silver. Drilling during 2014-2015 on the Blag gold-silver vein system has tested approximately 300 metres of strike length and 100 metres at depth in the vicinity of the historic small scale underground workings. The zone remains open along strike and down dip.
Previous work completed at the Blag target area includes geologic mapping, soil sampling and trenching in the area north of the historic Blag pit. In additional to the principal structure related to the historic mine exploration has defined two principal vein trends hosted in andesite tuff named the Santos and Blag Vein Swarm trends as well as the Blag Dome Target.
Within the Blag concession, three dominant epithermal quartz vein trends have been identified with help from the LiDAR survey data. The first set of veins are oriented between 340°-0°, are near vertical, and are similar to the veins exploited at the historic La Luna mine. These veins are typically narrow and can form swarms or silicified zones over several metres with only narrow argillic alteration halos. They constitute the bulk of the anomalous veins encountered along the Santos trend and have returned the best geochemical results to date. The second and third vein sets are oriented between 015-020° and 040-055? and dip steeply towards the northwest (local exceptions can be found). A high density of these veins can be found along the Blag Vein Swarm trend. These veins are more consistent with the regional epithermal vein trend, observed at prospects like Riscos de Oro and Guapinol, and have a similar orientation to those found underground at the Blag mine. The second and third vein sets are more coherent and often contain higher grade silver values.
Numerous anomalous quartz vein float samples have been collected at surface with grades up to 50.3 g/t Au and 1,200 g/t Ag. Gold highlights for the trenching program include intercepts of 4.30 g/t/2.80m, 2.67 g/t/4.50m and 1.21 g/t/6.40m located along the central Santos trend (trenching results are summarized below). LiDAR topographic data over the area has outlined numerous well defined cross-cutting structures which are inferred to be the surface expressions of the underlying epithermal veins and silicified fault zones. The majority of these structures have coincident soil and rock gold anomalies associated with them with samples located directly on top of the resistant features.
Epithermal veins were first discovered at Blag in the late 1960’s and the area has undergone several exploration and exploitation programs during the past 40 years. Economic grade Au-Ag intercepts drilled by Rosario in 1973-74 allowed for quick advancement of the prospect with production starting in 1975 and ending in 1978. Historical records show that the mine produced 1,262 oz gold and 92,707 oz silver (34,134 short tons at 0.037 opt gold and 2.716 opt silver) from a shallow open pit (200 metres long) and one underground level developed at 46 metres depth (150ft).
Drilling in 2014 and 2015 by Calibre has been successful in expanding the Blag Gold-Silver Vein System with intercepts including;