Hydrothermal Gold Deposit Features
- Gold prospect located in the the north of Colombia covering more than 7,000 hectares
- Located in the Segovia Belt. A geological region where alluvial and hydrothermal gold veins deposits are currently under production regime (ie. Mineros S.A.)
- Evidence of gold veins through drilling (DDH), surface sampling and structural simulations.
- Potential gold veins resources have been detected and modelled by SRK and Snowden.
- Drilling sampling (DDH) shows that potential sets of veins can extend from 1 to 10 metres @ 10 to 20 g/t
- Similar deposits have been found and exploited in South America by Yamana Gold (El Penon, Mina Florida) and Brio Gold Inc. (Pilar Mine)
El Bagre project is placed in the Segovia Belt which allocate several mesothermal gold veins deposits. Quartz alteration and gold mineralisation found in old mining operations and acquired from surface sampling and Diamond Drilling (DDH) campaigns within the tenement, evidence the likelihood to discover a narrow mesothermal gold vein deposit of about 1.2 to 2.5 metres width.
Historically, veins and alluvial gold deposits within El Bagre Project are have been identified” (SRK, 2018)
“The Project is prospective for vein gold mineralisation and placer-alluvial gold” (SRK, 2018)
“Sampled vein material taken from artisanal drifts yielded anomalous gold values, indicating the veins on the property may be acting as the lode source of the alluvial mineralization.” (Snowden, 2009)
“El Bagre project has Au mineralization associated with embedded veins in granodiorites rocks” (Brexia, 2012)
El Bagre Project is a Gold exploration target located in Antioquia Colombia within the Cauca and the Segovia belts where the main gold deposits are placed. The tenements extend for 7,013 hectares along the occidental side of the course of the Nechí river (Figure 1) being neighbour of Mineros S.A. (Figure 2), one of the largest gold producers in Colombia which extract gold from alluvial and gold veins deposits.
Alluvial deposits within the tenements of the project are evidenced by documented artisanal gold extraction activities in the area, gold veins deposits are denoted by quartz and gold alteration found in formal surface sampling and drilling exploration campaigns.
During the last decade, El Bagre has been studied and explored for local consulting companies as well as for two tier-1 international consulting companies, Snowden and SRK.
In 2009, Snowden assessed three gold veins sampling artisanal drift and found evidences of gold mineralisation in thickness from 25 to 40 cm which were also stated as the source of the alluvial mineralisation. Between 2010 and 2012, Brexia Resources, developed an extended exploration campaign in the area to identify and modelling veins continuity. Through geological and structural mapping and a surface sampling campaign and six diamond drill holes, the continuity of four veins was demonstrated. In 2018, SRK completed a broad review of available geological data that complemented with a site visit and surface sampling campaign. On line with previous results and conclusion reached in previous studies, SRK concluded that:
“The Project is prospective for vein gold mineralisation and placer-alluvial gold” and added “SRK considers there is reasonable expectation for the discovery of economic deposits of gold mineralisation”.
The extent of the alluvial deposit and potential gold resources have been estimated based on direct sampling of the placer reaching similar quality than the deposits currently exploited by Mineros S.A. Alluvial mineralisation of El Bagre. In addition to the sets of veins modelled by Snowden, SRK and Brexia; there is unequivocal evidence for the presence sulphide gold veins nearby that act as a primary source of the alluvial mineralisation. Geological data suggests that identified hydrothermal veins might be about 1.5 metres thick, extend for at least 100 metres in depth and contain high gold grade fluctuating between 12 and 20 g/ton.
Technical evidence from large gold exploitation companies, such as Yamana Gold, suggest that the extraction of potential narrow gold veins of El Bagre is feasible and can reach high recovery and productivity through Cut & Fill underground mining method.
Even though the remoteness of the area, El Bagre Project has been explored through direct geological, chemical and drilling sampling methods. Which, in addition to the evidence of historical working dating to the early 20th century provides additional information that helps to better understand the genesis, geology and mineralisation of the project.
Since 2009, three main exploration campaign and geological assessment have been conducted by Snowden (2009), Brexia Resources (2010-2012) and SRK (2018), and all of them have been dedicated to reach four goals:
- To determine the extent of placer - alluvial gold deposits and associated gold grade
- To confirm the presence and continuity of gold veins
- To estimate the thickness and ore grade of identified gold veins
- o verify the economic potential of the project
In 2009, Snowden was commissioned to assess three gold veins and the alluvial mineralisation. The assessment was conducted based on a site visit and conclusion supported by sampling obtained from both mineralisation that included:
Snowden stated that the grade of gold veins exposed on surface vary between 1.77 and 40.2 g/ton and that sampled veins from artisanal drift contained variable gold grade and ranged in thickness from 25 to 40 cm. Snowden asserted that the gold vein system under assessment acted as the source of gold of the alluvial placer mineralisation that was estimated at 2.0 g/ton.
- Alluvial material excavated from pits located in the border of the placer.
- Surface sampling from gold veins exposed on surface.
- Sampling of vein material taken from artisanal drifts.
Between 2010 and 2102, Brexia Resources began an exploration campaign dedicated to estimate the average grade of the alluvial deposit and the extent, shape and grade of gold veins. The exploration consisted in an extensive geological mapping and sampling campaigns. In 2010, 15 surface samples were collected from vein and rock chips, and 13 of them returned high gold grades.
n 2011 rock outcrops were sampled and assayed for both gold and base metals and exhibited heavy weathered (saprolite) and the presence of fresh material. Bexia developed a detailed geological model of gold veins and associated structures. Surface sampling and in-situ observations confirmed the rupture or discontinuity of several of the secondary veins within the project and most of the projected veins on the geological model were confirmed highlighting that Au grade in veins range from 3.8 to 18.0 g/ton and the average grade was estimated @ 12.5 g/ton.
In 2012 six DDH were executed aiming to identify and model the continuity of the veins within the property.
Brexia identified five veins of quartz with sulphide mineralisation linked to pyrite, galena and gold grouped in two main systems. The first one, with N55E/40SE orientation is located in the centre of the property and exhibit sets of fine quartz veins with presence of free gold. The second system, with 25NE/50Sw orientation, also shows free gold but embedded within thick quartz-veins.
Vein and alluvium samples were collected and sent to an SGS laboratory where the results were highly encouraged and conformed previous finding by Snowden.
In 2018, SRK conducted a broad review of available geological data acquired from previous exploration campaigns and a prolonged site-visit to develop an Independent Expert Report (IER) and determine the likelihood to discover both placer-alluvial and gold veins deposits.
SRK report was prepared to the standard of, and is considered, a Technical Assessment report under the guidelines of the 2015 edition of the Australian Code for Public Reporting of Technical Assessment and Valuation of Mineral Assets (the VALMIN Code).
The VALMIN Code incorporates “2012 edition of the Australian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves as published by the Joint Ore Reserves Committee of the Australasian Institute of Mining and Metallurgy, Australian Institute of Geoscience and Mineral Council of Australia” (the JORC Code)
Based on desktop review of datasets, reports and in particular, the previous drill hole information that was done in 2012, SRK concluded that El Bagre Project is prospective for vein gold mineralisation, and placer-alluvial gold and considers that there is reasonable expectation for the discovery of economic deposits of mineralisation. SRK added that the tenement offers prospective economically extractable gold and further exploration is justified.
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