Libanesa
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Property Type
Intermediate Sulphidation Epithermal Au/Ag – Base Metal Project
Size
14,500 ha
Status
Available for Partnership
Exploration Stage
Rock Chip sampling, geophysical survey, geological mapping
Maiden 2,000m drill program
Location
- Located at the north eastern margin of the Deseado Massif Au-Ag metallogenic Santa Cruz province, Argentina
- Approx. 70 km west from the port of Puerto Deseado
- 40 km northwest of the Cerro Moro Mine operated by Yamana Gold and 100 km northeast of the Don Nicolas mine operated by Cerrado Gold
The Libanesa project is a drill ready project hosting several diversified geological, geochemical and geophysical supported drill targets. Cerro Plomo is the principal target and is characterized by a well mineralized Au/Ag hydrothermal breccia that is exposed at surface, and supported by both chargeability and resistivity geophysical anomalies at depth. Peripheral polymetallic veins at the Libanesa Main prospect represent secondary targets and are supported by strong base metal +/- Au mineralization. The Lagunita prospect is a third prospective zone, which has reported some encouraging rock chip Au values from more typical low sulfidation type epithermal veins and breccias. This prospect requires additional surface exploration to vector into the potentially better mineralized parts of this extensive vein system, where intermittent vein occurrences, outcropping/subcropping through post mineral cover, have been mapped over a strike length of at least 2.3 km.
Mirasol initial field evaluation and targeting programs at Libanesa has identifying two main prospects:
- Libanesa Main prospect:
The Libanesa Main prospect lies along a dilational northwest structure and within a north-northwest corridor bounded by large-scale transfer faults that are clearly identified by the ground magnetic surveys. The main outcropping geological unit comprises partially welded and massive, crystal-rich, rhyolitic flow tuffs intruded by an andesitic to trachytic dike swarm that displays a radial distribution.
The principal target at Libanesa Main is the Cerro Plomo hydrothermal breccia pipe, which is approximatively 50m in diameter and forms an obvious geomorphic positive relief feature at this prospect. The Cerro Plomo breccia pipe has returned strong Au/Ag mineralization from both rock chip sampling and trench sampling (see Table 1, Figure 3 and 4), displaying a geochemical signature characterized by an Ag(±Au)-base metal association. A trenching program completed to explore under shallow lacustrine sediments confirmed the continuity of the mineralization, which remains open under a clay pan (dry lake) to the south. Highlighted results from the trench sampling include:
- 6m at 0.8 g/t Au, 243.8 g/t Ag and 0.4% Pb
- 10.5m at 0.98 g/t Au, 53.4 g/t Ag and 0.9% Pb
- 11m at 1.21 g/t Au, 13.5 g/t Ag and 1.4% Pb
These positive geochemical results are coincident with shallow and deep-seated geophysical anomalies below the Cerro Plomo target that are defined by the Magnetotellurics (MT) and Audio MT (AMT) geophysical surveys completed by Mirasol (2009/2010 and 2019), further strengthening the target.
In addition, a series of epithermal polymetallic veins (Bajo Aspero, Anibal, NE Zone), located peripheral and outboard from the Cerro Plomo breccia system, and associated with patchy argillic/pyritic alteration, have returned a strong Ag-Au-Pb-Zn and As-Sb-Te geochemical signature. Notably, the Au values do not correlate well with other metals, but Ag values are strongly correlated with Pb, Cu and Sb (+/-As,Te). This distribution of mineralization suggests the presence of at least two mineralization events related to the polymetallic veins and the Cerro Plomo hydrothermal breccia at the Libanesa Main prospect.
- Lagunita Prospect:
The Lagunita prospect, located approximately 6 km north of Cerro Plomo, is a 10 km2 erosional window exposed through the quaternary gravel cover, where reconnaissance prospecting has identified multiple quartz veining and structural breccia occurrences. The local geology is comprised of small outcrops of Jurassic aged fine ash, rhyolitic tuffs, andesitic dykes and minor calcareous rocks. A strong northwest structural trend appears to focus pervasive silicification and emplacement of crystalline, drusy and saccharoidal quartz veinlets. At Lagunita, rock chip geochemistry returned good Au values (see Table 1) with lower Ag values and base metals including Pb, Zn and Cu, thus displaying a more typical low sulfidation epithermal signature and clearly distinguishing the Lagunita veins from the breccias and polymetallic veins located at the Libanesa Main prospect.
Table 1: Au and Ag geochemistry result statistics
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