Cordoba Minerals Identifies New Porphyry Copper Target Immediately West of the Alacran Deposit Intrusive Breccias Point to Mineralized Porphyry Source of the Alacran Copper-Gold Deposit Exploration Drill Program Planned
Cordoba Minerals Identifies New Porphyry Copper Target
Immediately West of the Alacran Deposit
Intrusive Breccias Point to Mineralized Porphyry Source of the
Alacran Copper-Gold Deposit
Exploration Drill Program Planned
TORONTO, ONTARIO, October 30, 2018: Cordoba Minerals Corp. (TSX-V:CDB;
OTCQX:CDBMF) (“Cordoba” or the “Company”) today provides an update on recent
exploration activities at its Alacran Deposit, located within the 100%-owned San Matias
Copper-Gold Project in Colombia. A detailed investigation into the source of Alacran
mineralization has led to the identification of a potential porphyry copper-gold source located
immediately west of the Alacran Deposit. Drill targets are being finalized ahead of a planned
1,500 metre diamond drill program.
Highlights
• Two distinct styles of mineralization have been identified at Alacran: 1. Replacement
(or manto) copper-gold mineralization accounting for the bulk of the Alacran
Deposit’s Mineral Resources (Indicated: 36.1 million tonnes grading 0.57% copper
and 0.26 g/t gold - Inferred: 31.8 million tonnes grading 0.52% copper and 0.24 g/t
gold - refer to Cordoba’s February 26, 2018 news release); and 2. Carbonate-base
metal (“CBM”) feeder zones. New evidence from surface mapping and drill hole re-
logging suggests that both mineralization types are truncated to the west by late-
mineral intrusive breccias.
• Two distinct types of intrusive breccia have been identified: andesitic and dacitic
composition. Both are interpreted to have been emplaced along the same structures
that earlier introduced the Alacran mineralizing fluids.
• While both breccia types contain rock fragments with replacement and CBM styles of
mineralization, the dacitic breccia also contains clasts of porphyry-style
mineralization with potassic alteration, which may be an indication of a nearby source
of porphyry copper-gold mineralization.
“We are very pleased by the considerable progress being made at our Alacran Deposit,”
commented Mario Stifano, President and CEO of Cordoba Minerals. “Through new surface
mapping and by re-studying historical diamond drill core, our geological team has identified
clasts of porphyry-style mineralization contained within intrusive breccias. We are in the
process of finalizing drill targets and expect to commence diamond drilling in the coming
weeks.”
Figure 1: Schematic image showing conceptual porphyry copper-gold target at Alacran.
Mineralization Styles Identified at Alacran
Previously, the focus of exploration at Alacran was to identify massive magnetite and
sulphide mantos that replace the Unit 2 carbonate-rich mudstone. This style of mineralization
extends over approximately 900 metres from South to Central Alacran and can have a true
thickness of up to 40 metres (refer to Figure 2 below). In the north of the Deposit, the manto
mineralization transitions to CBM feeder-style mineralization.
Figure 2: Alacran manto with massive magnetite and sulphides.
The CBM feeder zones consist of carbonate, sericite and albite containing pyrite,
chalcopyrite and sphalerite. Hydrothermal fluids are interpreted to have moved along the
bedding of the volcano-sedimentary host rocks by exploiting fractures and porosity.
Figure 3: Feeder mineralization hosted in fine tuff and siltstone.
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Intrusive Breccias Are Key to Understanding Alacran Mineralization
During recent “boots on the ground” fieldwork, Cordoba’s geologists noted that current
artisanal mining located near the town of Alacran had exposed a body of intrusive breccia.
Through subsequent mapping and drill core re-logging, Cordoba’s geologists have been able
to identify two distinct types of breccia, each containing clasts with porphyry-style alteration
and mineralization.
The andesitic breccia has a porphyritic andesite matrix altered to sericite and albite. It
contains clasts of fine, equigranular to porphyritic diorite showing phyllic alteration.
Mineralized clasts are principally manto-style massive sulphide, but some zones also contain
CBM fragments.
Figure 4: Andesite breccia.
The dacitic breccia is particularly interesting because it has a porphyritic dacite matrix and
contains angular clasts of hornblende porphyry with both potassic and phyllic alteration.
Importantly, the clasts with potassic alteration also contain porphyry-style A veins.
Figure 5: Dacite breccia.
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Previously identified internal metal zoning patterns within the Alacran Deposit (refer to
Cordoba’s August 8, 2018 news release), which show increased gold, copper, silver and
zinc values in the Central and Northern portion of the Deposit, are now believed to be
spatially related to the breccias.
Figure 6: Breccias related to mineralized zones in the Alacran Deposit.
Evidence of a Nearby Mineralized Porphyry Deposit
Altered porphyry clasts are present in both the dacitic and andesitic breccias; however, only
in the dacitic breccia are clasts with potassic alteration observed. These fragments have
disseminated magnetite and feature sinuous Type A veinlets of saccharoidal quartz
containing magnetite and chalcopyrite.
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Figure 7: Porphyritic fragments with Type A veinlets.
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Silicified country rock fragments containing quartz veins and disseminated magnetite,
chalcopyrite, pyrite and molybdenite have also been identified. Quartz clasts in the breccia
are also thought to be “vein clasts” that consist entirely of mineralized vein material.
Figure 8: “Vein clasts” as well as silicified country rock fragments containing chalcopyrite,
pyrite, disseminated magnetite and quartz veining.
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Unidirectional Solidification Textures (“USTs”) contained within the porphyry clasts are often
seen in porphyry deposits at the top or “apical” portions of the intrusive stock in association
with potassic alteration and Type A veining.
Figure 9: Unidirectional Solidification Textures.
Given the potential impact of these recent observations, the Company has decided to delay
the Alacran Preliminary Economic Assessment until the area of interest has been explored
with drilling.
Technical Information & Qualified Person
The scientific and technical information in this release has been reviewed and verified by
Dale A. Sketchley, M.Sc., P.Geo., a Qualified Person for the purpose of National Instrument
43-101. Mr. Sketchley is a consultant to Cordoba Minerals and is considered i ndependent
under National Instrument 43-101. Mr. Sketchley is a geologist with over 40 years in the
mineral exploration, mining and consulting industry. He is a Member of the Association of
Professional Engineers and Geoscientists of British Columbia (APEGBC) and the Canadian
Institute of Mining and Metallurgy (CIMM).
An independent, National Instrument 43-101 compliant, technical report for the Alacran
Deposit, dated April 10, 2018 and prepared by Amec Foster Wheeler Americas Limited, is
available under the Cordoba’s SEDAR profile at www.sedar.com and on Cordoba’s website
at www.cordobaminerals.com.
Corporate Update
Eugene Schmidt was instrumental in identifying new prospective targets at Alacran and in
the greater San Matias District. Having completed this objective, he will transition back to a
consultant role to advise the Company during exploration and drilling at Alacran as well as at
Perseverance in Arizona, USA. Although no longer acting as Vice President, Exploration, he
will continue to generate new ideas and potential projects for Cordoba.
About Cordoba Minerals
Cordoba Minerals Corp. is a Toronto-based mineral exploration company focused on the
exploration and acquisition of copper and gold projects. Cordoba is currently focused on its