Eloro Resources Ltd. has reported results of comprehensive mineral determination studies from characteristic rock samples gathered from three mineralized sectors at the La Victoria Gold/Silver Project. The studies have established free silver, free gold, sulfide gold and silver, and alloy gold and silver occur in a complex set of sulfide mineralization at La Victoria, as stated in drill data.
A total of eighteen samples from San Markito, Rufina, and Victoria sectors were examined using a range of methods including; Synchrotron X-ray Fluorescence (SXRF), Electron Microprobe analysis, X-ray Diffraction, Polarizing and Scanning Electron Microscopy, and SXR Absorption Near Edge Structure. The samples were taken to the Department of Earth Sciences at Western University, London, Ontario, Canada. Studies were overseen by Department Director Dr. Neil Banerjee, and included in a Master’s Thesis by Ms. Kelsey Rozon.
As Ms. Rozon notes (2018, p83), “La Victoria also has some common minerals with nearby high-sulphidation epithermal deposits found at La Arena, Lagunas Norte, and Shahuindo including: arsenopyrite, chalcopyrite, covellite, enargite, pyrite and silica with alunite-dickite. Additional minerals that La Victoria has in common with nearby gold-bearing deposits include galena, jarosite, pyrophyllite, scorodite, sericite, sphalerite, and tetrahedrite.”
Rozon (2018, pp78-81) observes the positions of the samples used in these studies comparative to an overprinting of a porphyry copper intrusion marked by the intensity and style of alteration and mineralization. Plenty of data comes from the Rufina sector, for which a porphyry copper intrusive is shown in the core logs with chalcopyrite and pyrite and sporadic covellite. Rozon notes four distinct positions to which the samples belong, including “marginal to a copper porphyry but below the lithocap [at both shallow and deep crustal levels]; upper portion of a porphyry copper core zone at a shallow crustal level”; and “upper portion of a porphyry copper deposit.”
Based on these understandings, Eloro plans to return to the core storage unit to explore the diamond drill core for the various alterations noted in Rozon (2018) in the context of the mapping works done by Dr. Osvaldo Arce in 2016.
The Rufina sector samples revealed sulfide veins to overprint as a minimum of two episodes of quartz veining in a source rock of quartz monzonite. Microscopic gold transpired with the sulfide veins near chalcopyrite and arsenopyrite (Rozon, 2019, p39). Electron microprobe testing exposed a range of minerals, including electrum (a blend of gold and silver) found in scorodite (a hydrous iron arsenate from the oxidation of arsenopyrite). X-Ray Fluorescence (SXRF) analysis revealed the presence of gold with universal base metals and typical crustal metals. The gold is spread in both scorodite and arsenopyrite.
The San Markito samples were chosen and tested to compare various intrusive phases. Granites and associated intrusives were observed with phyllic alteration and advanced argillic alteration in quartz veins with small sulfide veins materializing as a cross-cutting stage. The electron microprobe exposed approximately the same set of minerals as the Rufina samples, but that silver was in the mineral argentite, which was present as separate grains and within the adjacent minerals arsenopyrite and scorodite. Enargite, a classic indicator mineral for epithermal gold mineralization, was also seen in the samples.
The Victoria sector samples included four with quartz veins, two with sulfide veins, and two granite/monzogranite samples. Veins were seen with phyllic and advanced argillic alteration, indicating potential copper porphyry synergies. Gold was found in the sulfide veins, granular in character, and associated with arsenopyrite and chalcopyrite. The electron microprobe revealed a wide suite of gold and silver bearing minerals including; native gold, acanthite, argentite, titanite, argentojarosite, and tetrahedrite. Free gold is present within arsenopyrite and associated in proximity to other minor minerals. Rozon notes (2018, p52) that “the free gold is granular and microscopic, while the electrum is granular, fibrous, and microscopic”. An examination of the gold/silver rations in electrum provided values of between 2 gold: 1 silver to 16 gold: 1 silver. The analysis notes the presence of maldonite, an alloy of bismuth and gold analogous to electrum, the alloy of silver and gold. The SXRF data confirmed that gold is associated with scorodite and arsenopyrite as in other samples.
The Synchrotron X-Ray Near-Edge Absorption study was done on numerous samples where free gold had been detected in other tests so as to reveal the valence state of gold. If the gold possesses zero valence, it is native gold. Samples revealed this to be decisively the case at the Rufina and Victoria South Sectors; San Markito was not analyzed.
These studies show the manifestation of free gold and free silver as well as sulfide hosted gold and silver as well as lesser quantities of alloyed gold and silver in mineralization at La Victoria.
These studies clearly reveal the variety of gold and silver at La Victoria and where it is located, including evidence for a copper porphyry. It is especially exciting to see free gold and free silver at La Victoria as well as the alloys with very high gold to silver contents. We are now going to take several specific high-gold and high-silver samples and complete grind size and liberation testing. Now that we know how the gold and silver occur in these samples, we can look at optimizing a recovery process.
Tom Larsen, CEO, Eloro.
“Other than minor occurrences of electrum and maldonite gold and silver do not occur in solid solution. We are cautiously optimistic that the pitted and fractured nature of the arsenopyrite and scorodite will allow the gold to be liberated at a coarse grind.”
Jim Steel MBA P.Geo., SVP Mining, Eloro.
Furthermore, Dr. Bill Pearson, P.Geo. has resigned from the position of President of Eloro Resources Ltd. The Corporation thanks Dr. Pearson and bids him well.
Jim Steel MBA P.Geo., a Qualified Person in the context of National Instrument 43-101, has read and approved the technical content of this Press Release.
Rozon, K. 2018. “Geochemical Analysis of a Low-Sulfidation Epithermal Deposit on the La Victoria Property in the Ancash Department of the Republic of Peru.” Unpublished Master’s Thesis, The Department of Earth Sciences, University of Western Ontario, London, Ontario, pp39-83.