A total of 154 diamond drill holes have been drilled on the Property since 1993, totalling 43,993 metres.
The first holes were drilled in 1993 by Placer Dome. Placer Dome completed six diamond drill holes totalling 1,953 metres. The objective of the program was to evaluate the Property for its porphyry copper potential.
Between 1995 and 1998, General Minerals Corporation completed 61 diamond drill holes for a total of 15,815 metres. The drill program was intended to further evaluate the mineralized area identified by Placer and to develop a mineral resource.
Between July 2007 and October 2008, Los Andes Copper completed a total of 79 diamond drill holes, totalling 22,616 metres. The Los Andes Copper drilling was carried out to refine the geological model, evaluate the continuity of mineralization, evaluate possible deposit extensions and confirm the mineralization defined by the prior drill campaigns. No holes were drilled within the San José 1/3000 claim area. At the time of the drill campaign, Los Andes Copper only owned of 51 % of this claim area.
During 2015, to better understand the project, the Los Andes Copper geologists re-logged all of the 146 drill holes located within the property and prepared a new geological model. This model was drill tested in 2015/2016 with a total of 8 drill holes and 3,670 metres. These drill holes were drilled within the San José 1/3000 claim area, the first time this area had been drilled since 1997.
The historical drilling generally went through the supergene mineralisation and then then only a short distance in the primary mineralisation. This means that there are various drill holes, especially in the central core where the drill holes finished in grades above 0.5 % Cu or in geological units which indicate that the drill hole is still in the upper part of the system. This detailed review showed that the historical logging and geological model had not properly identified the importance of the higher grade early diorite porphyry and hydrothermal breccias.
Table summarising the different drilling campaigns
|Description||Year||No. of Drill Holes||Total Meterage (m)|
|General Minerals||1996 / 1997||61||15,814.90|
|Los Andes Copper||2007 / 2008||79||22,615.60|
|Drill holes used in 2014 resource estimate||146||40,383.45|
|Los Andes Copper||2015 / 2016||8||3,609.65|
2015 / 2016 Drill Program
The 2015 / 2016 drill program was designed to test the new geological model and support assumption that the higher grades are associated with the early diorite porphyry and the later hydrothermal breccias.
Drill Hole V2015-01
This hole was drilled in the northern part of the central core. The purpose of this hole was to demonstrate whether the high grade mineralisation associated with the diorite porphyry extended 200 metres to the west from the historical drill holes.
The top of bedrock was located at 68.70 metres and the drill hole intersected the diorite porphyry with potassic alteration at a depth of 216 metres and continued within this unit to the end of the hole at 476 metres. The average grade with the diorite porphyry was 260.40 metres at 0.467 % Cu, 285 ppm Mo and 1.0 g/t Ag from a down hole depth of 216.0 metres, this included 0.601 % Cu, 258 ppm Mo and 1.2 g/t Ag over a length of 64.00 metres. The drill hole supports the continuity of the higher grade diorite porphyry to the west and demonstrated that the mineralisation is open at depth.
Drill Hole V2015-02
This hole was drilled on the western edge of central core. The aim of this hole was to drill to the west of the known mineralisation, seeking to intersect the lower grade granodiorite intrusive which defines the western limit of the project.
The drill hole did not intersect the granodiorite intrusive but drilled the andesite host rock with potassic alteration from a depth of 60.10 metres to a depth of 288.00 metres where it intersected a tonalite porphyry which continued to the end the hole at 459.80 metres.
Within the andesite, from a depth of 142.00 metres, the average grade was 0.60 % Cu, 170 ppm Mo and 1.84 g/t over 52.00 metres, associated with stronger alteration. The average grade for the whole drill hole was 0.35 % Cu, 107 ppm Mo and 1.0 g/t over a length of 399.65 metres.
While the drill hole did not reach the western limit of the project, it showed that the mineralised system extended further westward than the proposed model and demonstrated the core of the project has significant sections with grade of greater than 0.6 % Cu.
Drill Hole V2015-03
This hole was drilled in middle of central core, 140 metres to the east of V2015 02. The aim of the hole was to test the depth extension of the mineralisation identified in the shorter historical drill holes which finished in good mineralisation at a depth of approximately 200 metres.
The drill holes intersected andesitic bedrock with supergene mineralisation at a depth of 44.1 metres. The supergene mineralisation continued to approximately 80 metres and the grade over this sequence was 0.743 % Cu, 146 ppm Mo and 1.9 g/t Ag over 39.10 metres.
From a depth of 141.10 metres, the drill hole intersected a sequence of ingenious breccias, hydrothermal breccias and a diorite porphyry to a depth of 444.8 metres. The higher parts of the sequence are identified by the quartz sericite alteration and high pyrite to chalcopyrite ratio. With depth, the potassic alteration increases and the pyrite to chalcopyrite ratio decreases although never below 1:1. This would indicate the drill hole is still in the higher part of the porphyry system and there is potential for higher grades at depth. The grade over this sequence is 0.404 % Cu, 241 ppm Mo and 1.1 g/t Ag over a length of 303.7 metres.
At a depth of 444.80 metres the drill hole intersected an andesite with potassic alteration and is notable for the low copper grades and the higher molybdenum grade. The grades are 0.172 %Cu, 332 ppm Mo and 0.4 g/t Ag over a length of 90.20 metres. This andesitic sequence is interpreted as being the potassic central of the porphyry system.
Drill Hole V2015-04
This hole was drilled in the northern extent of the central core, 180 metres to the north-west of drill hole V2015-01, to test the northern extension of the mineralisation identified in the first drill hole.
The drill hole intersected the diorite intrusive bedrock at a depth of 64.90 metres and continued in the same type of rock to a depth of 656.00 metres, except for a short 15 metres sequence of tonalite porphyry. A leached cap extended from 64.9 metres to 186.0 metres.
From a depth of 186.0 metres to a depth of 656.0 metres, a length of 470.0 metres, the average grade was 0.350 % Cu and 152 ppm Mo with 0.8 g/t Ag. This included 44.0 metres with an average grade of 0.448 % Cu, 96 ppm Mo and 1.1 g/t Ag.
While this hole did not intersect the higher grade diorite porphyry identified in historical drill hole V-39, it has shown that moderate grade mineralisation extends further north than previously demonstrated in the 2014 block model.
Drill Hole V2015-05
This hole was drilled in the eastern part of the central core, 280 metres to the south-east of V2015-03. The purpose of this hole was to demonstrate the northern extension of the hydrothermal breccias identified in the relogging of the historical drill holes to the south.
The top of bedrock was located at 36 metres with the drill hole intersecting a sequence of andesitic host rock, cut by diorite porphyry and hydrothermal breccias. The leached zone extended to a depth of 72 metres before entering the supergene mineralisation. From 72.0 metres to a depth of 192.0 metres, a length of 120.0 metres, the average grade was 0.537% Cu, 169 ppm Mo and 1.4 g/t Ag.
The drill hole intersected a hydrothermal breccia from 492.2 metres to 544.3 metres, a total length of 52.1 metres, with an average grade of 0.812 % Cu, 190 ppm Mo and 2.0 g/t Ag. This supports the extension of the higher grade breccias from the south.
Drill Hole V2015-06b
The V2015-06a hole could not pass through the gravels.
The V2015-06b hole was drilled in the north east extent of the central core, 270 metres to the north-east of drill hole V2015-01, between two outcropping late stage diatremes. The new geological model indicates the potential for porphyry style mineralisation in this area. If proven this would open up a large area within the 2014 block model that is currently identified as waste rock.
The drill hole intersected a post mineral dacite dyke at a depth of 3.0 metres and was stopped at a depth of 67 metres. The drill hole has not been assayed.
Drill Hole V2015-07
This hole was drilled to 150 metres south of drill hole V2015-05 to test central core of the project area.
The drill hole could not pass through the gravels and was abandoned at a depth of 52.00 metres.
Drill Hole V2015-08
This hole was drilled in the eastern part of the central core, 270 metres to the north of V2015-05. The aim of the hole was to show the depth extension of the mineralisation beneath the historical drill holes drilled in this area.
From a depth of 3.0 metres to a depth of 61.5 metres the hole intersected a post mineralisation dacite dyke. The drill hole then entered the andesite host rock that has been intruded by small tourmaline and hydrothermal breccias. The leached zone extended to 130.0 metres. From a depth of 130.0 metres, the drill hole intersected 502.0 metres @ 0.631 % Cu, 209 ppm Mo and 1.3 g/t Ag.
The upper part of drill hole was andesite host rock with strong stockwork and minor intervals of breccia with a post mineral dacite dyke from 184.0 metres to 198.8 metres. The mineralisation in this section was 54.0 metres @ 1.023 % Cu, 128 ppm Mo and 1.4 g/t Ag from 130.0 metres downhole depth and 37.0 metres @ 0.92 % Cu, 132 ppm Mo and 2.0 g/t Ag from a downhole depth of 198.8 metres. This high grade mineralisation is near surface and would be mined in the early years of any mine project.
At a depth of 235.8 metres the drill hole intersected the early diorite porphyry and intersected a total of 396.3 metres @ 0.566 % Cu, 233 ppm Mo and 1.2 g/t Ag. This intersection shows the importance identifying the early diorite porphyry and shows the good primary mineralisation in the central core of the project. From a depth of 632.0 metres to the end of drill hole at 725.5 metres the drill hole intersected tonalite porphyry which from 706.0 metres was cut by a hydrothermal breccia. The average grade over this section was 93.5 metres @ 0.362 % Cu, 566 ppm Mo and 0.7 g/t Ag. The substantially higher molybdenum values had a significant effect on copper equivalent grade.
This drill hole demonstrates the near surface higher grades in the supergene enriched andesite and the good grades that are associated with the early diorite porphyry. The drill hole confirmed the new geological model in this area demonstrating that the grades seen in the shorter historical drill holes extended to at least 700 metres below the surface.
2015-2016 Drilling Campaign
|Hole Number||Length (m)||Depth Downhole
|Cu %||Mo ppm||Ag g/t||CuEq %*|
* Copper equivalent grade has been calculated using the following expression: Cu Eq (%) = CuT (%) + 2.5 x Mo (%) + 110.55 x Ag (g/t), using the metal prices: $ 2.2 / lb. Cu, $5.5 / lb. Mo and $15.2 / Oz Ag. All thicknesses from intersections from drill holes are down-hole drilled thicknesses. True widths cannot be determined from the information available.