December 28, 2015 @ 09:30
AURYN Mining Chile SpA is pleased to announce the high-grade gold epithermal mineralization in Merlin and Fortuna targets at Altos de Lipangue Project.
- Over 5 kilometers of mineralized veins were mapped.
- Over 1,600 rock and trench samples were collected.
- High-grade Au ± Cu ± Pb ± Zn mineralized veins.
- In Merlin I, the vertical zoning in quartz-carbonates textures suggest a preserved epithermal system.
The trenching program in the Merlin-Fortuna targets was finished, and over 1,600 channel and grab samples were collected. Over 5 km of lineal structures were recognized and the structural corridors are still open to be extended in all directions. (See figure 1)
Trenching and sampling helped to define structural settings, mineralization and alteration patterns in the veins system, as well helped to find new veins in soil-alluvial covered sectors.
The mineralization in Merlin and Fortuna targets is characterized by several epithermal veins, mainly quartz veins accompanied with Fe-Mn-Cu oxides at surface. In some trenches and old adits quartzsulfides veins were mapped. Sulfides in veins are dominated by pyrite, chalcopyrite, arsenopyrite, galena, sphalerite and minor covellite.
Veins are hosted generally in the cretaceous granodiorite, developing up to 30 meters argillic alteration (kaolinite) halo with quartz-limonites veinlets and stockwork. To the northwest, ocoitic andesites of Veta Negra Formation hosts part of the vein system (Merlin I). In this host rock, the alteration is restricted to centimeters halo, also accompanied by quartz-carbonate-limonite veinlets.
In Merlin I, the veins outcrops are very rare due to the artisanal exploitation in the past. Therefore, argillic alteration corridors, quartz floats and faults/veinlets structures are the most common evidence at surface.
In the northwestern extension of Merlin I vein, at old Caren Mine, almost three underground adits were recognized, but only two of them is possible to have partial access today. In the first sampling completed of grab samples returned up to 66.5 g/t Au, and channel samples confirmed high-grade mineralization, with 1.2 m @ 26 g/t Au, 0.27 %Cu, 0.14 %Pb, 0.25 %Zn, including 0.4 m @ 51 g/t Au. Systematic sample at different adits levels was done and results are pending.
During adit mapping was possible to recognize carbonate cemented breccias with massive quartzsulfides fragments in upper topographic levels, in transition to quartz-chalcedonic and crystalline quartz with dog teeth textures with sulfides filling spaces at low topographic levels. Crystalline mineral association is quartz-pyrite – chalcopyrite – galena – sphalerite ± covellite.
In the southern extension of Merlin I vein the highly Au (over 3 g/t Au) anomalous grab samples in old adits suggested its continuity, and successful further exploration by trenching extended the structure the south adding 0.8 km to the total 1.9 km. (See figure 2 and Table 1)
In Merlin I vein widths varies from 0.15 to 0.5 meters and shows wider alteration halo in the granodiorite host rock compared to the ocoitic andesitic.
Merlin III vein is an E-W trending vein and intersects the Fortuna NNW structure close to the old Fortuna de Lampa Mine.
Merlin III has a 2 (two) meters average vein width. The vein is characterized by massive and breccia textures with crystalline quartz-hematite-jarosite.
The intersection between Merlin III (E-W), Fortuna Oeste (NW) and Fortuna central (NNW) develops a highly prospective zone in Altos de Lipangue. (See Figure 3 and Table 2)
The mineralization at Fortuna target is represented by several parallel veins with NS to NNW trending. Mineralization is dominated by Au ± Cu ± Pb ± Zn bearing veins. (See figure 3 and Table 3, 4 and 5)
Veins are characterized by quartz textures, dominated by crustiform, banded quartz-chalcedoniasulfides and massive types. The widths varies from 0.1 meter to 2 meters, and quartz stockwork several meters halo is very common in the granodiorite host rock. Sericite selvages are very common in the veins-host rock contact.
The hydrothermal alteration is dominated by strong argillic corridor (kaolinite – smectite), and is possible to see extended up to 200 meters width in FH trench sector. This is supported by geophysical response in the CSAMT survey. (See Fortuna targets maps)
Similar to Merlin veins, several veins were discovered after trenching, and the most common evidence are quartz floats and strong argillic alteration corridors.
Mineralized intervals Tables
In the mineralized calculations the cut-off grade considered to build is >0.1 g/t Au. There are considered from 2 (two) continuous samples over cut-off, and no more than 2 (two) continuous samples below cut-off inside the interval. Measure of intercepts is a sum of sample size, and grades expressed are an average grade of samples considered inside the interval.
Sample Preparation and Quality Control
Supervision and organization of trench grab samples was undertaken by AURYN personnel. Samples were collected in channel sampling method with a minimum 0.30 m and maximum 1m interval depending on veins and host rock mineralization, and 2m samples are collected in intervals with no evident mineralization or alteration. Then samples are placed in cloth bags by employees of AURYN under the supervision of Luciano Bocanegra, Mario Arancibia and Felipe Astudillo, project Geologists. Samples were catalogued by AURYN geologists and stored in a secure location. Blank and standard material was also inserted at random intervals.
Assays are delivered to the Andes Analytical Assay laboratory in Santiago Chile. The assaying procedure includes ICP determination of the values for 33 elements plus Fire Assay to determine the values for gold. Standards, blanks and duplicates are routinely added to ensure compliance with QA/QC protocols.