Highlander Silver Provides Update on La Estrella Geological Model and Drilling Plans - Seite 2
Leandro Echavarria, the Company´s Vice President Exploration commented, "Our geologic model is based on the detailed drill core logging and surface mapping carried out by the technical staff at Highlander Silver. This model serves as the cornerstone for effective drill targeting to expand known mineralization zones. Identification of upflow channels that focused mineralised fluids allow us to target zones with potential for higher grade".
Regional Geology
The area is cut by a set of regional faults that control volcanism and emplacement of dome complexes (Fig. 1). Both the Julcani mine (105 million ounces of silver produced from high grade vein
mineralisation averaging 16 ounces per ton since production started by Buenaventura in 1953) and the La Estrella deposit are emplaced along the fertile Julcani-Huancayo fault. La Estrella sits at
an important inflection zone on the fault, generating a transtensional structural setting which enabled shallow dome emplacement, hydrothermal activity and Ag-Au ±Pb ±Zn ±Cu mineralisation.
Fig. 1 La Estrella regional geology and structural setting
Local geology, hydrothermal alteration and mineralisation
Hydrothermal alteration and mineralisation at La Estrella are associated with a dome complex intruded along transtensional zones, exploiting the rheologic contrast between limestones and red beds
(Fig. 2). The dome complex is more than 2 km long in the North to South direction and has a maximum width of 900 m, dipping about 35° West, and it is formed by numerous, irregular intrusion facies,
where earlier basal facies are overlain by younger facies (Fig. 3).
The dome complex is cut by NE faults producing uplifted and down dropped blocks, with maximum measured displacements of about 80 m. These faults probably acted simultaneously with dome emplacement, acting as upflow channels of the hydrothermal fluids, and exert control on the alteration and mineralisation distribution.
Fig. 2 Lithology map showing dome facies
Fig. 3. Cross section showing dome facies and distribution of mineralisation. Note distribution of strongest mineralisation, hosted by the lower dome facies. Mineralised intercepts (not true widths) in hole DDH-E23 include: A) From 111.90 m to 122.5 m (interval 10.60 m) of 0.68 g/t Au and 12.43 g/t Ag. B) From 154.0 m to 163.3 m (interval 9.00 m) of 0.66 g/t Au and 138.58 g/t Ag. C) From 166.6 m to 197.2 m (interval 30.00 m) of 0.63 g/t Au and 7.94 g/t Ag.