NGEx Minerals Ltd. (TSX: NGEX) (OTCQX: NGXXF) is pleased to announce the discovery of a major new copper-gold porphyry system at its 100% owned Lunahuasi high-grade copper-gold-silver project in San Juan, Argentina. This discovery confirms our interpretation of the geological setting of the Lunahuasi mineralization and opens up an entirely new, very large-scale exploration target at the project. Drillhole DPDH027 demonstrates that the Lunahuasi system has similar size and scale potential to other deposits in the Vicuña cluster, with the added advantage of the large, very high-grade copper-gold-silver high-sulphidation epithermal structures which are unique to Lunahuasi. PDF Version

Lunahuasi Geology Drill Plan (CNW Group/NGEx Minerals Ltd.)

Lunahuasi Porphyry Section (CNW Group/NGEx Minerals Ltd.)

Highlights:

• Drillhole DPDH027 drilled across the HS zone before entering a porphyry copper-gold deposit at about 1,262m. The hole ended in mineralization at a depth of 2,005m and the full scale of the system remains unknown. The hole intersected:
  • 1,619.40m at 0.87% copper equivalent from 385.60m, including:
    • 876.40m at 1.13% CuEq from 385.60m in disseminated, stockwork and lode high-sulphidation mineralization, including:
      • 205.05m at 2.04% CuEq from 590.65m, plus:
    • 743.00m at 0.56% CuEq from 1,262.00min porphyry-style mineralization cut by discreet high-sulphidation zones, including:
      • 18.00m at 2.68% CuEq from 1,343.00m
      • 17.80m at 1.23% CuEq from 1,495.20m
• Drillhole DPDH029 is the southernmost hole drilled to date at Lunahuasi. It intersected the HS zone over its entire length, with early porphyry veins occurring from 1,100m providing a clear vector towards the porphyry to the west of the end of the hole. The hole intersected:
  • 823.10m at 1.17% CuEq from 776.90m, including:
    • 157.70m at 2.18% CuEq from 776.90m
    • 38.90m at 4.35% CuEq from 870.70m
    • 153.50m at 1.98% CuEq from 1,207.50m, including:
      • 9.00m at 7.33% CuEq from 1,352.00m

Wojtek Wodzicki, President and CEO, commented, “Drillhole DPDH027 opens up an entirely new dimension of the Lunahuasi project, adding to the potential of what this giant mineral system will ultimately become. The possible presence of a large copper-gold porphyry system associated with the high-grade vein-hosted HS mineralization has been a part of our geological interpretation from the beginning, and we have now confirmed that we were on the right track. While our near-term exploration efforts will continue to target the unique high-grade vein system which we view as having the most important immediate potential, the presence of a porphyry system significantly increases the long-term value of the project.

We continue to successfully expand the HS system, and drillhole DPDH029 extended mineralization by over 400m to the south of hole 27. The north-south dimension of the key high-grade zone has now been expanded to over 1,100m and remains open in all directions. Hole DPDH029 ended in mineralization in argillic alteration associated with the high-sulphidation system overprinting early porphyry veins. This provides a clear vector indicating that the porphyry lies to the west of the end of this hole, some 500m south of the intersection in DPDH027, confirming its location and size potential.”

Copper equivalent (CuEq) for drill intersections is calculated based on US$3.00/lb Cu, US$1,500/oz Au and US$18/oz Ag, with 80% metallurgical recoveries assumed for all metals. The formula is: CuEq % = Cu % + (0.7292 * Au g/t) + (0.0088 * Ag g/t). 

Estimated true widths are rounded to the nearest metre for widths over 10 m and to the nearest 0.1 m for widths less than 10 m, as this better reflects the precision of the estimates. True widths should be regarded as approximate as these are derived from an estimation that uses a preliminary interpretation of the geological model and are subject to change as more information becomes available.  Intervals greater than 300m are interpreted as bulk disseminated and stockwork mineralization and drilled width is equal to estimated true width.

DPDH027 was collared from the same platform as DPDH021 and angled to the southwest (255^o) with a dip of -46^o to test for a southern extension to the mineralization in hole 21. This hole was also planned to go as deep as possible to test the concept of a porphyry system located to the west of the main HS zone. Partial results from this hole, to a depth of 1,075.1m, were released on January 20 and February 19, and are included in the table of full results above.

Within the HS alteration and mineralization, the characteristic zonation of porphyry veining can be recognized with D veins first intersected at 480m, B veins at 920m and A veins at 1,270m. This zonation indicates that the hole intersected the eastern flank of a porphyry centre, with the hole ending in mineralized diorite porphyry with potassic alteration. The same zonation is also seen to the north, in DPDH028, and to the south, in DPDH029, however neither of those holes appears to have been drilled deep enough to intersect the porphyritic rocks or potassic alteration and both ended in the HS system. Together these three holes provide clear evidence of a western porphyry system with a minimum north-south extent of 700m.

DPDH029 was collared adjacent to DPDH027 and drilled towards the southwest (229^o) at a dip of -50 degrees in order to explore the southern extent of the deposit. Partial results from this hole, to a depth of 1,060.0m, were released on February 19, and are included in the table of full results above.

As with other holes, numerous intersections of HS mineralization were drilled by this hole, including a broad zone from 776.9m which includes some higher-grade sub zones. The zone from 776.90m to 934.60m correlates well with the large zone in DPDH021, 22, 27 and 28 and indicates that the HS system remains strong here and is completely open to the south.

This hole intersected the same zonation of porphyry veining, overprinted by the HS alteration, but stopped short of intersecting potassic alteration or mineralized diorite porphyry.

Discussion

Drillhole DPDH027 confirms the presence and location of a significant porphyry copper-gold centre which is intimately related to the high-grade HS mineralization that makes up the currently known deposit. The hole transited the eastern flank of the porphyry system, where it has in large part been overprinted by the subsequent HS alteration, before intersecting a multi-phase, mineralized diorite porphyry with potassic alteration at a depth of about 1,262m. Below this depth, the hole is primarily in potassic altered and mineralized porphyry and country rock, still overprinted by discreet zones of HS alteration and mineralization, and it ended in mineralization at 2,005m.

In addition to the characteristic alteration, veining and porphyry intrusive rocks, the change from HS to porphyry mineralization is distinguished by a change in copper mineralogy from enargite / chalcocite in the HS to chalcopyrite +/- bornite in the porphyry. This change can be identified visually, and geochemically by a decrease in the cyanide-soluble values of the sequential copper analyses and an increase in the residual copper values. See technical notes below for additional details.

The density of early veins varies throughout the section below 1,200m with more abundant veins associated with higher copper and gold grades. Early lithologies, including early porphyry phases and fine-grained andesite and rhyolite country rock, and breccias, contain the highest density of veining and consequently the highest grades. In contrast, a late phase porphyry is clearly identified by diminished alteration and relatively scarce early veins and carries lower grades. The highest grades in this section occur in areas with overprinting HS mineralization, with individual samples between 1.0% and 7.0% CuEq.

Table 2 gives an example of these differences by showing the average grade of a representative interval of the different geological units in DPDH027. The overall grade of the Lunahuasi porphyry system will depend on the relative abundance of these different porphyry phases and the intensity of the associated veining, and the high grade of the densely veined early porphyry intervals is encouraging.

The Phase 3 drill program was completed on May 8^th with a total of 25,003m drilled in 24 holes as shown in Table 3. In addition to these holes, three geotechnical holes and two water wells were completed. All equipment and personnel have now been demobilized from the site and all field activities have been concluded. Table 4 shows assay intervals released to date by the date of the news release. Assays for the final 12 holes representing 10,369m of drill core are pending.

Qualified Persons and Technical Notes

The scientific and technical disclosure included in this news release have been reviewed and approved by Bob Carmichael, B.A.Sc., P.Eng. who is the Qualified Person as defined by NI 43-101. Mr. Carmichael is Vice President, Exploration for the Company.

Samples were cut at NGEx’s operations base in San Juan, Argentina by Company personnel. Diamond drill core was sawed and then sampled in maximum 2-meter intervals, stopping at geological boundaries. Core diameter is a mix of PQ, HQ and NQ depending on the depth of the drill hole. Samples were bagged, tagged and packaged for shipment by truck to the ALS preparation laboratory in Mendoza, Argentina where they were crushed and a 500g split was pulverized to 85% passing 200 mesh. The prepared sample splits were sent to the ALS assay laboratory in Lima, Peru for copper, gold and silver assays, and multi-element ICP. ALS is an accredited laboratory which is independent of the Company. Gold assays were by fire assay fusion with AAS finish on a 30g sample. Copper and silver were assayed by atomic absorption following a 4-acid digestion. Samples were also analyzed for a suite of 48 elements with ME-MS61 plus mercury and a sequential copper leach analysis was completed on each sample with copper greater than 500ppm (0.05%). Sequential copper analysis involves the sequential leaching of the sample by acid, followed by a cyanide solution. It can be used to differentiate copper speciation, with copper oxide minerals leachable with acid and secondary copper minerals (enargite, chalcocite, covellite) leachable by cyanide. The residual copper remaining following the sequential leaches it typically contained in chalcopyrite and bornite. Copper and gold standards as well as blanks and duplicates (field, preparation, and analysis) were randomly inserted into the sampling sequence for Quality Control. On average, 9% of the submitted samples are Quality Control samples. No data quality problems were indicated by the QA/QC program.

Copper equivalent (CuEq) for drill intersections is calculated based on US$3.00/lb Cu, US$1,500/oz Au and US$18/oz Ag, with 80% metallurgical recoveries assumed for all metals. The formula is: CuEq % = Cu % + (0.7292 * Au g/t) + (0.0088 * Ag g/t).

Estimated true widths are rounded to the nearest metre for widths over 10 m and to the nearest 0.1 m for widths less than 10 m, as this better reflects the precision of the estimates. True widths should be regarded as approximate as these are derived from an estimation that uses a preliminary interpretation of the geological model and are subject to change as more information becomes available. Intervals greater than 300m are interpreted as bulk disseminated and stockwork mineralization and drilled width is equal to estimated true width.

Collar coordinates in Table 3 are updated with higher precision survey data as it becomes available and may change between news releases.

About NGEx Minerals

NGEx Minerals is a copper and gold exploration company based in Canada, focused on exploration of the Lunahuasi copper-gold-silver project in San Juan Province, Argentina, and the nearby Los Helados copper-gold project located approximately nine kilometres to the northeast in Chile’s Region III. Both projects are located within the Vicuña District, which includes the Caserones mine, and the Josemaria and Filo del Sol deposits.

NGEx owns 100% of Lunahuasi and is the majority partner and operator for the Los Helados project, subject to a Joint Exploration Agreement with Nippon Caserones Resources LLC, which is the indirect 30% owner of the operating Caserones open pit copper mine located approximately 17 kilometres north of Los Helados. Lundin Mining Corporation holds the remaining 70% stake in Caserones.

The Company’s common shares are listed on the TSX under the symbol “NGEX” and also trade on the OTCQX under the symbol “NGXXF”. NGEx is part of the Lundin Group of Companies.

Additional information relating to NGEx may be obtained or viewed on SEDAR+ at www.sedarplus.ca.