Orex Minerals Inc.
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San Luis del Cordero

On 4 December 2017, Orex Minerals Inc. announced the signing of a "Letter of Intent" to acquire a 100% interest in the San Luis del Cordero Project ("SLC") in northern Durango State, Mexico, from Exploraciones del Altiplano SA de CV.A formal agreement was announced in a news release on January 26, 2018.

SLC is a skarn and epithermal vein hosted silver-copper-zinc district, located 155 kilometres NNE of the City of Durango and immediately north of the town of San Luis del Cordero. Old mine workings and mineralized showings wrap around a quartz-feldspar-porphyry intrusive. The mineral concessions total 2,825 hectares.

Location Map


A central Tertiary quartz-feldspar-porphyry intrusive, which has an east-west extent of approximately 3 km and a north-south extent of approximately 1.5 km, penetrates Jurassic-Cretaceous sedimentary packages of limestone conglomerates (Ahuichila Fm.), shales and sandstones (Caracol Fm.), limestones (Cuesta del Cura Fm.) and shales, limestones, sandstones (La Casita Fm.). Contact metasomatic skarn development has occurred along the north, east and south sides of the intrusive, with the western boundary marked by a fault contact.

Vein Hosted Mineralization.

The most tested vein on the property is the Santa Rosa Vein, which has been drilled over a 500 metres strike and down to a depth of 250 metres. It is high-grade and varies between 0.40 to 2.62 metres in thickness. In the early 20th century, past production extracted approximately 70,000 tonnes, grading 600-700 g/t silver and 2.0 % copper, along 150 metres strike and down to about 100 metres depth. Sampling by Altiplano of pillars on levels 1 and 3 averaged 570 g/t silver and 2.3 % copper. Tetrahedrite (Cu,Fe,(Ag))12Sb4S13 is the main copper bearing mineral, along with chalcopyrite CuFeS2, although in the oxidized zone, the secondary minerals malachite Cu2CO3(OH)2 and azurite Cu3(CO3)2(OH)2 are common. The second most explored vein is India Bonita, located 1 km to the northeast.

Skarn Hosted Mineralization.

The Santa Rosa East Skarn is delineated by grade and texture, rather than by structure. Intersections vary in core length from 2.19 to 30.60 metres, with an average true width of 9.0 metres. Most of this zone is covered by alluvium. This zone has been traced for about 700 metres along strike. There are also sub-parallel skarn zones to the main skarn. Overall, skarns have been traced around the intrusive, as well as adjacent to QFP dykes, for about 5.5 km.

On the eastern end of the skarn rim is the untested La Puerta Target. Small old pits and terreros expose hornfels, with grossular garnet as exoskarn, with malachite coatings on fractures. This target shows up strongly in the polymetallic soil geochemistry and has not yet been drilled.

On the southern side of the skarn rim is the Canal Zone Target, 1.3 km south of the Santa Rosa Mine. Both exoskarn and endoskarn can be seen along the contact, with different phases of intrusive, and mineralization in both the QFP and the sedimentary rocks. A short drift was sampled over 20 metres averaging 133 g/t Ag, 1.92 % Cu and 5.6 % Zn. Two drill holes have been drilled into this target, with hole PSLC-11-17 yielding 10.88 metres grading 59 g/t Ag, 0.3 % Cu and 7.2 % Zn. More drilling is warranted.

Geologic Outcrop Map

Mineral Resources

Class Tonnes Ag-Eq
Sta Rosa Vein Indicated 31,500 1,022.6 827.8 1.21 1.98 838,366 1.036
Sta Rosa Skarn Indicated 631,125 200.8 86.1 0.76 1.02 1,747,094 4.075
Total: Indicated 662,625 239.9 121.4 0.78 1.06 2,585,460 5.111
Sta Rosa Vein Inferred 218,437 955.4 716.4 1.12 3.62 5,031,291 6.710
Sta Rosa Skarn Inferred 2,566,875 214.9 95.7 0.72 1.26 7,897,950 17.734
Total: Inferred 2,785,312 273.0 144.4 0.75 1.45 12,929,241 24.445

A previous operator, Prospero Silver Corp., filed a Technical Report, dated October 1, 2014, on Mineral Resources for San Luis del Cordero. This Technical Report should now be considered as a "Historical Estimate" and Orex does not consider it as a current Mineral Resource for the purposes of NI-43101.

Hodson, T.W., 2014, NI 43-101 report on the initial resource estimate for the San Luis del Cordero Project, Durango State, Mexico. Prepared for Prospero Silver Corp. by Hodson Geological Ltd., effective date 1 Oct 2014, 62 p.

  1. Mineral Resources are not Mineral Reserves as there are insufficient studies to demonstrate economic viability.
  2. It cannot be assumed that all or any part of an Inferred Resource will be upgraded to an Indicated or Measured Resource as a result of continued exploration.
  3. Resources are reported at a silver-equivalent cut-off grade of 85 g/t.
  4. AgEq=Ag + [Cu% x 22.046 x Cu price x 31.103/Ag price + Zn% x 22.046 x Zn price x 31.103/Ag price]. Metal prices used in the formula = US$3.00/lb, Zn = US$0.90/lb.
  5. AgEq ozs = AgEq grams/31.103

Orex does not consider the 2014 Technical Report as a Current Mineral Resource Estimate as the 2015 and 2016 drilling campaigns have not been incorporated into the Estimate. Also, an Independent Qualified Person has not done sufficient work to re-classify this historical estimate as a Current Mineral Resource.

The 2014 "Historical Estimate" should be treated as a exploration guide and should not be relied upon for financial and/or mine modelling purposes.

Orex Minerals Inc.