La Estrella Project, Peru
AVAILABLE FOR JV
Epithermal gold and silver target available for option in the Huancavelica Department of southern Peru. Alianza and its previous partners have outlined a large epithermal system with a current surface expression of over 2 km in length and 600 m in width. Geophysical surveys have identified strong chargeability responses associated with surface mineralization and extension/offset chargeability anomalies at depth and on strike. To date, 41 holes have been drilled (8,661 m), with drill-indicated gold – silver mineralization at La Estrella extending for a minimum of 1,800 meters in a north-south direction and is upwards of 500 meters in width. Gold is estimated to be in the 0.40 to 0.50 gpt range and silver in the 10 – 15 gpt range. Higher grade intersections of gold and silver have also been intersected in drilling, including 11 meters @ 311.2 g/t silver and 0.59 g/t gold. These high grade silver intersections have yet to be systematically followed up.
The La Estrella project is located in the epithermal polymetallic belt of Peru, 130 km south of Huancayo. Access to the property is by 80 km of paved road from Huancayo and then maintained gravel road to the site. The 2,300 ha property is lies at elevations of 4,000 to 4,400 metres.
To date, a total of 41 holes have been drilled for a total of 8,661 meters. This total includes 30 diamond core holes for a total of 6,643.5 meters and 11 reverse circulation holes for a total of 2,017.5 meters.
Disseminated gold mineralization is dominantly hosted within dacite subvolcanic intrusions and andesitic volcanics. At least three significant hydrothermal alteration events related to gold and silver mineralization are seen in the drilling: 1) ‘main-stage’ pervasive silica-pyrite mineralization, mostly in the dacite, with 0.2 to 0.5 g/t gold and silver up to 2.0 g/t, 2) quartz-pyrite veining only in the andesite with up to 2.0 g/t gold and no silver and 3) late silica-gray-sulfide mineralization, possibly in veins or structures, with high grade silver 200 to 400 g/t and gold up to 8.0 g/t.
The hydrothermal system is very large and only poorly understood at this point in time, and it is believed that the mineralized system may be much larger than currently indicated by the historic drilling. Drilling indicates that the gold – silver mineralization is open to both the north and down-dip to the west with excellent exploration upside.
Gold and silver mineralization at Estrella is occurs primarily within the dacitic intrusive unit and to a much lesser extent in the overlying andesite unit, and it is controlled by pervasive and fracture-controlled silica-pyrite alteration. This mineralization is thick, consistent and remains completely open to both the west and north. Gold grades are directly related to the intensity of the silica-pyrite alteration. At least three pyrite phases are seen: pre-mineral, intra-mineral, and post-mineral. High grade silver (and sometimes gold) mineralization is associated with late, pervasive and fracture-controlled, fine-grained dark gray sulfides, which are various sulfosalts and base metals sulfides.
Based on the drilling completed to date, there appears to be a very strong positive correlation between gold and silver mineralization and pyrite. A detailed IP-Resistivity survey was completed over the property in 2013. As expected, a well-delineated chargeability anomaly was detected over the zone of known gold-silver mineralization. However, this survey continued north of the zone of known mineralization, and the IP anomaly continues to the north for a distance of approximately 700 meters. In addition, a second parallel, previously unknown, chargeability anomaly was identified northwest of the area of known mineralization. This anomaly is approximately 1,300 meters long and up to 400 meters wide and occurs in an area of predominately alluvial cover. One RC hole was drilled in the vicinity of this chargeability anomaly (prior to its delineation) but did not reach a depth to adequately test it.
Geophysical surveys have demonstrated a moderate to strong correlation between IP signal
strength and abundance of pyritic-associated gold, the predominant style of mineralization in La Estrella
dacitic rocks. In the northern portion of the area of interest, high chargeability response extends to depth northward and westward for over 1000 m. This chargeability lobe on the northwest side of the project area represents an untested target but it is unclear if this anomaly is due to pyrite-associated mineralization as seen to date or one of the two other styles of mineralization seen in drilling.
Importantly, bonanza-grade silver mineralization is hosted within recently recognized northeast-trending structural zones, which crosscut the two earlier types of mineralization. The northeast trending structures contain the highest grade silver mineralization on the property, including drill intersections up to 11 meters @ 311.2 g/t silver and 0.59 g/t gold (RC-E10 from 43-54 m). These structures have not been the target of any systematic step-out drilling. High-grade structures have only been intersected with three drill holes and remain entirely open along strike (SW-NE) and at depth. The following table contains significant high grade intercepts.
|From||To||Length||Gold grade||Silver grade|
|DDH E-23||Total Depth: 239.6 meters|
|Total mineralized intercept||84.4||197.2||112.8||0.41||21.4|
|DDH E-24||Total Depth: 296.3 meters|
|Total mineralized intercept||101.8||262.4||160.6||0.37||23.0|
|DDH E-25||Total Depth: 370.5 meters|
|Total mineralized intercept||75.0||276.4||201.4||0.35||12.9|
|DDH E-26||Total Depth: 323.2 meters|
|Total mineralized intercept||141.5||256.4||114.9||0.37||6.4|
|DDH E-27||Total Depth: 500.3 meters|
|Total mineralized intercept||188.0||280.9||92.9||0.31||3.4|
|DDH E-28||Total Depth: 500.3 meters|
|Total mineralized intercept||161.5||297.0||135.5||0.39||6.9|
|DDH E-29||Total Depth: 259.4 meters|
|Notes to Drill hole Table 1:|
|1. The assay data presented in Figure 1 have not been capped (top-cut).|
|2. Reported intervals were selected based upon general in situ economic value above $25.00 per tonne, metals prices were assumed at $1,000 gold and $20.00 silver.|
The Next Steps
Although no NI 43-101 resource has as yet been defined for the La Estrella, the property is not well understood but from and alteration-mineralization point of view, and overall, the project is believed to have excellent exploration potential.
Some of the more important features of the project are noted below:
- Known, large epithermal system present on the property (2+ km long and up to 600m wide)
- Property totals ~2,300 ha in size
- Strong zone of north-south-trending quartz veining and highly anomalous surface Au – Ag (in rocks)
- Drill-indicated gold – silver is open to north and down-dip to the west
- Excellent relations with local communities
- Previously unknown and poorly tested IP anomaly exists to the northwest of the known area of mineralization
- Untested, high quality targets already have been delineated,
- The project basically is “drill ready”
Alianza is seeking a partner to test the above-mentioned targets with the aim of delineating a large gold-silver epithermal deposit at La Estrella.