Mr. George Smith reports
CALIBRE MINING RC DRILLING PROGRAM ON THE 100% OWNED PRIMAVERA GOLD-COPPER PORPHYRY DEPOSIT INTERSECTS WIDESPREAD GOLD-COPPER MINERALIZATION, NICARAGUA
Calibre Mining Corp. has released results of its 2017 reverse circulation drilling program on its 100-per-cent-owned Primavera gold-copper porphyry project in Nicaragua.
Highlights:
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The 2017 RC drilling program consisted of 19 holes totalling 2,758.5 metres, including 12 holes at the Santa Juana target two kilometres south of the Primavera deposit and six holes testing the NE Extension anomaly one kilometre east of Primavera. Drilling to date has tested less than 5 per cent of the surface geochemical, geophysical and geological anomaly that defines the Primavera gold-copper district's potential.
- A maiden resource estimated in December, 2016, for the Primavera gold-copper porphyry deposit contains an inferred resource at a 0.5 g/t gold equivalent cut-off of 45.0 million tonnes grading 0.84 g/t Au Eq containing 782,000 ounces of gold, 1.7 million ounces of silver and 219 million pounds of copper (1.2 million ounces Au Eq).
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The 2018 exploration program has commenced with rock and soil geochemistry and geological mapping. Exploration in the first half of 2018 will also include further target definition as well as additional drilling to test new gold-copper zones.
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The 2017 drilling program intersected widespread porphyry-style alteration and mineralization with intervals including: 10.5 m grading 0.38 g/t Au and 0.03 per cent copper, 36.0 m grading 0.27 g/t Au and 0.05 per cent Cu, 160.5 m grading 0.11 g/t Au and 0.06 per cent Cu, 9.0 m grading 1.76 g/t Au and 0.02 per cent Cu, 76.5 m grading 0.11 g/t Au and 0.02 per cent Cu, and 45.0 m grading 0.16 g/t Au and 0.13 per cent Cu.
- The 2017 RC drilling program also included one drill hole drilled within the existing Primavera deposit and confirmed the width and grade of gold-copper mineralization, intersecting 234 m grading 0.83 g/t Au and 0.27 per cent Cu (1.25 g/t Au Eq) including 129 m grading 1.06 g/t Au and 0.28 per cent Cu (1.51 g/t Au Eq).
- Numerous high-priority drill targets prospective for further gold-copper porphyry mineralization continue to exist within the 5.0 km by 4.0 km Primavera target area with a second target area of 3.0 km by 2.0 km located five km west at San Isidro. Additional drilling will be completed in 2018.
Greg Smith, president and chief executive officer of Calibre, stated: "Drilling on our flagship 100-per-cent-owned Primavera gold-copper porphyry district has intersected widespread porphyry-style alteration and mineralization. These drilling results confirm the potential for further gold-copper porphyry discoveries within the Primavera district. The 2018 Primavera exploration program will include drill testing of additional gold-copper porphyry targets."
Hole ID Hole location From To Interval Au Cu Au Eq
(m) (m) (m) (g/t) (%) (g/t)
PRC17-001 Primavera deposit 3.0 237.0 234.0 0.83 0.27 1.25
Including Primavera deposit 108.0 237.0 129.0 1.06 0.28 1.51
PRC17-002 NE anomaly 69.0 79.5 10.5 0.38 0.03 0.44
And NE anomaly 130.5 166.5 36.0 0.27 0.05 0.36
PRC17-003 NE anomaly 0.0 160.5 160.5 0.11 0.06 0.20
PRC17-008 Santa Juana 69.0 78.0 9.0 1.76 0.02 1.79
PRC17-013 Santa Juana 0.0 76.5 76.5 0.11 0.03 0.14
PRC17-015 Santa Juana 0.0 141.0 141.0 0.06 0.01 0.08
PRC17-016 Santa Juana 103.5 148.5 45.0 0.16 0.13 0.37
Including Santa Juana 105.0 111.0 6.0 0.85 0.34 1.40
2017 RC drilling highlights. See associated table for complete results.
Intervals are core lengths/true widths are estimated to be 80 per cent to 90 per cent
of lengths.
Length weighted averages from uncut assays.
Au Eq g/t calculated using prices of $1,300 per ounce for gold and $3 per pound for copper.
2017 RC drilling program results
The 2017 drill program is the first drilling program at Primavera since 2012, and consisted of 19 reverse circulation drill holes totalling 2,758.5 metres completed between July and December, 2017. Most drill holes (17) were drilled at an angle of 60 degrees with two (PRC17-001 and PRC17-016) drilled at 65 degrees, and total length varied between 106.5 m and 237.0 m. The widespread and shallow program was designed as a prospecting initiative testing the broad anomalous gold and copper targets defined by soil and rock sampling, which are the most reliable exploration tools in this area of sparse outcrop.
The primary goal was to test a series of geochemical, geophysical, and geological targets outboard from the existing Primavera deposit. The high-priority targets include:
- The NE trend which covers an area two km by one km extending northeast from the existing deposit which was tested by six holes;
- The Santa Juana/San Francisco target with an extent of two km by two km, centred three km southeast of the Primavera deposit, which was tested by 12 drill holes.
Additionally one RC drill hole in the 2017 drilling program was completed within the Primavera deposit with hole PRC17-001 intersecting:
- 234.0 m grading 0.82 g/t Au and 0.26 per cent Cu (1.15 g/t Au Eq), including;
- 129.0 m grading 1.06 g/t Au and 0.28 per cent Cu (1.42 g/t Au Eq).
Hole PRC17-001 was drilled in proximity to diamond drill hole PR-11-001, which intersected 262.0 m grading 0.49 g/t Au and 0.22 per cent Cu, and diamond drill hole PR-11-002 which intersected 261.7 m grading 0.73 g/t Au and 0.29 per cent Cu, confirming the grade and continuity to the gold-copper mineralization.
Six holes (PRC17-002, -003, -004, -017, -018 and -019) were completed between 250 m and 1,000 m east of the known deposit and intersected variably altered and mineralized volcanic and intrusive rock with intervals including: 10.5 m grading 0.38 g/t Au and 0.03 per cent Cu, 36.0 m grading 0.27 g/t Au and 0.05 per cent Cu, and 160.5 m grading 0.11 g/t Au. The drill holes in this area are generally anomalous in molybdenum with individual samples ranging up to 73 parts per million Mo over 1.5 m (PRC17-003 162.0 m to 163.5 m).
A total of 12 holes have been drilled in the Santa Juana target (PRC17-005 to 016) intersecting: 9.0 m grading 1.76 g/t Au and 0.02 per cent Cu, 76.5 m grading 0.11 g/t Au and 0.02 per cent Cu, and 45.0 m grading 0.16 g/t Au and 0.13 per cent Cu. The geology of the area is dominantly andesitic volcanics with variable amount of diorite. Additionally, drill hole PRC17-016 intersected a quartz-rich breccia which returned 6.0 m (105 m to 111 m) grading 0.85 g/t Au and 0.34 per cent Cu with individual samples including 2.38 g/t Au and 0.49 per cent Cu.
In both areas tested during 2017 the geology consists largely of andesitic volcanic flows and tuffs with narrow to moderate sections of diorite intrusions. Alteration is widespread and includes propylitic (epidote-chlorite-pyrite), potassic (biotite and magnetite) as well as common silicification and quartz plus or minus carbonate) veining. Sulphides occur as disseminations and within the quartz veining and consist of variable amounts of pyrite and chalcopyrite. Rare molybdenite was also noted.
2018 exploration and drilling program
The 2018 exploration program has commenced with rock and soil geochemistry and geological mapping. Exploration in the first half of 2018 will also include additional target definition as well as additional drilling to test new zones.
Principal targets in the Primavera area include:
- Expansion of the Primavera deposit to depth and along strike;
- The NE trend covers an area two km by one km extending northeast from the existing deposit;
- The Santa Juana/San Francisco target with an extent of two km by two km, centred three km southeast of the Primavera deposit.
Additional prospective zones for further gold-copper porphyry mineralization exist within the 5.0 km by 4.0 km Primavera target area as defined by anomalous gold and copper in rock and soil samples, magnetic and radiometric geophysical anomalies, and targets where geological mapping has identified porphyry-style mineralization or alteration.
A second target area has been identified five km west of Primavera. At San Isidro a 2.0 km by 3.0 km anomaly has been defined using rock and soil geochemistry. The geology appears similar to Primavera, dominated by andesitic volcanics and diorite intrusions. The geochemical signature varies slightly with significantly elevated lead, zinc and antimony occurring with the copper and gold. Additional target definition exploration is continuing and the first drilling program at San Isidro is planned for 2018.
Drilling to date has tested less than 5 per cent of the surface geochemical, geophysical and geological anomaly associated with the project.
Primavera Au-Cu porphyry deposit
The Primavera deposit consists of classic porphyry-style gold-copper mineralization. Porphyry-style mineralization is hosted within the volcanic and intrusive rocks and associated with both potassic and propylitic alteration. The chalcopyrite-plus-or-minus-bornite copper mineralization is primarily hosted by a quartz-veinlet stockwork and overall sulphide content is quite low. Drilling encountered intense zones of potassic alteration dominated by potassium feldspar, biotite and magnetite. In addition, the presence of sheeted and banded quartz-magnetite veins, along with the alteration and mineralization textures, further confirmed the potential for a gold-copper porphyry system. Primavera is the first porphyry gold-copper project discovered in Nicaragua and the mineralization remains open for expansion.
A maiden resource estimated in December, 2016, for the Primavera gold-copper porphyry deposit contains an inferred resource at a 0.5 g/t Au Eq cut-off of 45.0 million tonnes grading 0.84 g/t Au Eq containing 782,000 ounces of gold, 1.7 million ounces of silver and 219 million pounds of copper (1.2 million ounces Au Eq).
INFERRED RESOURCE AT A CUT-OFF OF 0.5 G/T AU EQ FOR THE PRIMAVERA AU-CU PORPHYRY DEPOSIT
Tonnes Au Ag Cu Au Eq Au Ag Cu Au Eq
(g/t) (g/t) (%) (oz) (oz) (pounds) (oz)
44,974,000 0.54 1.15 0.22 0.84 782,000 1,661,000 218,670,000 1,200,000
Canadian Institute of Mining, Metallurgy and Petroleum definition standards were followed
for the 2016 resource estimate which used ordinary Kriging grade estimation within a
3-D block model with mineralized zones defined by wireframed solids. A base cut-off grade
of 0.5 g/t Au Eq was used for reporting resources.
Densities varied by material type and ranged from 2.4 for saprolite to 2.71 for diorite and
the volcanics.
Numbers may not add exactly due to rounding.
Gold equivalent (Au Eq) calculated using $1,300 per oz for gold, $2.40 per pound for copper,
and $20 oz for silver.
Mineral resources that are not mineral reserves do not have economic viability.
The quantity and grade of reported inferred resources in this estimation are uncertain in
nature and there has been insufficient exploration to define these inferred resources as an
indicated or measured mineral resource and it is uncertain if further exploration will result
in upgrading them to an indicated or measured mineral resource category.
WSP's resource estimate for Primavera is based on drill core assay results from a total of
33 holes totalling 13,491 m of drilling and 52 trenches totalling 660.9 m.
Variograms were generated for gold, copper and silver and search parameters established for
grade interpolation using kriging.
All details of the resource estimate are summarized in a National Instrument 43-101 technical
report available on SEDAR prepared by Todd McCracken, PGeo, of WSP, who is independent of
Calibre and a qualified person as defined by Section 1.5 of National Instrument 43-101.
Calibre mining best practice
Calibre is committed to best practice standards for all exploration, sampling and drilling activities. Drilling is being completed by independent drilling contractors. Analytical quality assurance and quality control procedures include the systematic insertion of blanks and standards into the sample strings. Samples are placed in sealed bags and shipped directly to Acme Labs (a Bureau Veritas Group company) in Managua, Nicaragua, for sample preparation and then to Vancouver, Canada, for 50-gram gold fire assay and ICP-MS multielement analyses.
The technical content in this news release was read and approved by Mr. Smith, PGeo, president and chief executive officer of the company, who is the qualified person as defined by National Instrument 43-101.
About Calibre Mining Corp.
Calibre owns a 100-per-cent interest in over 413 square kilometres of mineral concessions in the mining triangle of northeast Nicaragua including the Primavera gold-copper project and Santa Maria gold project. Additionally the company has optioned to Iamgold (176 square kilometres) and Centerra Gold (253 square km) concessions covering an aggregate area of 429 square km and is party to a joint venture on the 33.6 square km Rosita D gold-copper-silver project with Rosita Mining Corp. Major shareholders of Calibre include gold producer B2Gold Corp., Pierre Lassonde and management.
Hole ID Hole location From To Interval Au Cu Au Eq
(m) (m) (m) (g/t) (%) (g/t)
PRC17-001 Primavera 3.0 237.0 234.0 0.83 0.27 1.25
Including Primavera 108.0 237.0 129.0 1.06 0.28 1.51
PRC17-002 NE anomaly 69.0 79.5 10.5 0.38 0.03 0.44
NE anomaly 130.5 166.5 36.0 0.27 0.05 0.36
PRC17-003 NE anomaly 0.0 160.5 160.5 0.11 0.06 0.20
PRC17-004 NE anomaly 66.0 100.5 34.5 0.10 0.04 0.17
PRC17-005 Santa Juana 103.5 112.5 9.0 0.15 0.01 0.17
Santa Juana 126.0 147.0 21.0 0.10 0.02 0.13
PRC17-006 Santa Juana 1.5 31.5 30.0 0.06 0.01 0.08
Santa Juana 127.5 145.5 18.0 0.06 0.04 0.11
PRC17-007 Santa Juana 1.5 67.5 66.0 0.09 0.02 0.11
Including Santa Juana 31.5 67.5 36.0 0.13 0.02 0.15
With Santa Juana 64.5 66.0 1.5 1.54 0.01 1.56
PRC17-008 Santa Juana 69.0 78.0 9.0 1.76 0.02 1.79
Including Santa Juana 69.0 72.0 3.0 5.06 0.00 5.07
Santa Juana 103.5 114.0 10.5 0.07 0.01 0.09
PRC17-009 Santa Juana 19.5 24.0 4.5 0.05 0.01 0.06
Santa Juana 55.5 63.0 7.5 0.07 0.01 0.09
Santa Juana 73.5 76.5 3.0 0.15 0.02 0.17
PRC17-010 Santa Juana 24.0 111.0 87.0 0.03 0.02 0.06
PRC17-011 Santa Juana 105.0 126.5 21.5 0.07 0.01 0.08
Including Santa Juana 109.5 121.5 12.0 0.11 0.00 0.12
With Santa Juana 114.0 115.5 1.5 0.49 0.00 0.50
PRC17-012 Santa Juana 0.0 13.5 13.5 0.05 0.01 0.07
Santa Juana 31.5 36.0 4.5 0.21 0.01 0.23
Including Santa Juana 31.5 33.0 1.5 0.53 0.00 0.53
Santa Juana 70.5 72.0 1.5 0.41 0.01 0.42
Santa Juana 102.0 136.5 34.5 0.10 0.02 0.13
Santa Juana 124.5 127.5 3.0 0.42 0.07 0.53
PRC17-013 Santa Juana 0.0 76.5 76.5 0.11 0.03 0.14
Including Santa Juana 25.5 37.5 12.0 0.19 0.04 0.25
And Santa Juana 58.5 61.5 3.0 0.32 0.01 0.34
And Santa Juana 69.0 76.5 7.5 0.32 0.01 0.34
Santa Juana 105.0 145.5 40.5 0.08 0.02 0.10
PRC17-014 Santa Juana 1.5 7.5 6.0 0.05 0.04 0.11
Santa Juana 18.0 21.0 3.0 0.05 0.01 0.06
Santa Juana 76.5 81.0 4.5 0.13 0.02 0.17
Santa Juana 96.0 103.5 7.5 0.07 0.00 0.07
PRC17-015 Santa Juana 0.0 141.0 141.0 0.06 0.01 0.08
Including Santa Juana 40.5 52.5 12.0 0.20 0.02 0.23
And Santa Juana 111.0 126.0 15.0 0.09 0.02 0.12
PRC17-016 Santa Juana 75.0 78.0 3.0 0.28 0.00 0.28
Santa Juana 103.5 148.5 45.0 0.16 0.13 0.37
including Santa Juana 105.0 111.0 6.0 0.85 0.34 1.40
With Santa Juana 108.0 111.0 3.0 1.63 0.37 2.21
And Santa Juana 138.0 145.5 7.5 0.04 0.44 0.73
PRC17-017 NE anomaly 67.5 76.5 9.0 0.06 0.03 0.11
NE anomaly 106.5 127.5 21.0 0.07 0.08 0.19
Including NE anomaly 115.5 124.5 9.0 0.14 0.12 0.32
PRC17-018 NE anomaly 3.0 28.5 25.5 0.02 0.03 0.06
NE anomaly 40.5 88.5 48.0 0.02 0.03 0.07
PRC17-019 NE anomaly 49.5 90.0 40.5 0.02 0.03 0.06
Intervals are core lengths/true width are estimated to be 80 per cent to
90 per cent of lengths.
Length weighted averages from uncut assays.
Au Eq g/t calculated using $1,300 per oz gold and $3 per pound copper.
We seek Safe Harbor.
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