Ayawilca

Mineral Resources

The Mineral Resources presented here are in accordance with the NI 43-101 Inferred Mineral Resource category, at a cut-off grade equivalent to approximately US$60/t, as estimated by Roscoe Postle Associates Inc. (RPA) of Toronto, Canada. The reader is advised to review the full NI 43-101 Report dated June 29, 2016.

The Zinc Zone Inferred Mineral Resources are estimated to total 18.8 million tonnes grading 8.2% Zinc equivalent (ZnEq). The Zinc Zone Mineral Resources occur in three separate areas, West, Central, and East (see table below) over an east to west mineralized trend of 1.5 kilometres. The mineralization remains open in most directions. The Zinc Zone Mineral Resources are hosted by Pucará Group limestone approximately 200 metres thick, beneath a sandstone 'cap' about 150 metres thick. The deposit style is a carbonate-hosted replacement deposit (CRD), with zinc sulphide (sphalerite) occurring in multiple generations as semi-massive sulphide replacements of the limestone together with other (mostly iron) sulphides. The Zinc Zone deposit is made up of multiple, gently dipping lenses or ‘mantos’ and at least one vertical chimney at West Ayawilca where the zinc grades are higher.

INFERRED MINERAL RESOURCES AT AYAWILCA ZINC ZONE BY AREA (JUNE 29, 2016)

Area

Tonnage (Mt)

ZnEq

(%)

Zn

(%)

Pb (%)

In (g/t)

Ag

(g/t)

Zn

(Mlb)

Pb

(Mlb)

In

(kg)

Ag

(Moz)

West

4.5

10.6

7.6

0.2

100

17

765

15

452,000

2.5

Central

9.5

7.4

5.2

0.2

72

13

1,094

39

685,000

3.9

East

4.8

7.4

5.6

0.3

52

16

587

27

248,000

2.5

Total 

18.8

8.2

5.9

 

0.2

74

15

2,446

82

1,385,000

8.8

Note: Metal price assumptions for the Zinc Zone Mineral Resource estimate were: US$1.00/lb Zn, US$500/kg In, US$20/oz Ag, and US$1.00/lb Pb. Metal recovery assumptions were: 90% Zn, 75% In, 50% Ag, and 75% Pb. The ZnEq(%) value was calculated using the following formula: ZnEq(%) = [Zn(%)*US$11.88+Pb(%)*US$4.16+In(g/t)*US.30+Ag(g/t)*US.28]/ US$11.88. A cut-off of 5% ZnEq was used for the resource estimation above. 

Zinc mineralization was discovered at Ayawilca in 2012, while the Company was seeking to expand its silver resources along strike (2km to the south) of the Colquipucro Silver Deposit. The Company completed its initial Zinc Mineral Resource estimate in February 2015.


The Tin Zone Inferred Mineral Resources are estimated to total 5.4 million tonnes grading 0.89% Tin equivalent (SnEq). The Tin Zone resources occur in two separate lenses lying immediately underneath the Zinc Zone Mineral Resources, and do not overlap. The tin occurs as disseminated cassiterite, together with minor chalcopyrite, in massive to semi-massive pyrrhotite lenses at the contact between the Pucará Group limestone and underlying phyllite of the Excelsior Group.

INFERRED MINERAL RESOURCES AT AYAWILCA TIN ZONE (JUNE 29, 2016)

Tonnage (Mt)

SnEq

(%)

Sn (%)

Cu

(%) 

Ag (g/t)

Sn

(Mlb)

Cu

(Mlb) 

Ag 

(Moz)

Tin Zone

5.4

0.89

0.76

0.31

18

90

37

3.1

Note: Metal price assumptions for the Tin Zone Mineral Resource estimate were: US$9/lb Sn, US$3/lb Cu, and US$20/oz Ag. Metal recovery assumptions were: 85% Sn, 75% Cu, and 50% Ag. The SnEq(%) value was calculated using the following formula: SnEq(%) = [Sn(%)*US$130.36+Cu(%)*US$41.26+Ag(g/t)*US.28]/ US$130.36. A cut-off of 0.45% SnEq was used for the resource estimation above.

Zinc Mineralization

Zinc mineralization is associated with semi-massive to massive sulphide mantos of pyrite, pyrrhotite and sphalerite with minor to trace galena, chalcopyrite and arsenopyrite. Magnetite is also present in the peripheral areas. Zinc is hosted together with high levels of indium, a high-value technology metal, inside the lattice of the sphalerites. Sulphides replace the matrix and clasts of the altered limestones, commonly accompanied by chlorite-sericite, iron carbonate, and clays.

As of December 2015, Tinka has drilled 27,650 metres in 76 diamond drill holes at Ayawilca since 2011/12.

Selected zinc drill intersections include:

  • A13-05: 212.9 metres at 5.3 % zinc & 83 grams per tonne (g/t) indium from 130.3 metres depth, including 16.0 metres at 18.1 % zinc & 120 g/t indium from 150.0 metres depth, and 10.0 metres at 12.9 % zinc & 670 g/t indium from 316.0 metres depth;
  • A14-22: 32.8 metres at 7.4 % zinc & 66 g/t indium from 211.2 metres depth, including 5.8 metres at 16.8 % zinc & 170 g/t indium from 228.0 metres depth, and 31.0 metres at 6.3% zinc & 101 g/t indium from 283.5 metres depth;
  • A12-08: 36.5 metres at 6.5 % zinc & 63 g/t indium from 162.0 metres depth, and 38.0 metres at 4.6 % zinc & 117 g/t indium from 266.0 metres depth;
  • A12-04A: 20.0 metres at 7.1 % zinc & 127 g/t indium from 260.0 metres depth, including 12.0 metres at 10.5 % zinc & 200 g/t indium from 266.0 metres depth.

Tin-Copper Mineralization

Tin mineralization was discovered in the Central, East, and North Ayawilca areas following the re-assaying of 2012-2013 drill holes . Tin-copper mineralization lies within tabular 'mantos' beneath, and separately to, the zinc sulphide mantos. The tin occurs predominantly as cassiterite within massive iron sulphide (pyrrhotite) mantos, together with minor chalcopyrite.

Selected tin-copper drill intersections include:

  • A15-40: 50.5 metres at 1.23% tin and 0.16% copper from 328.0 metres depth, including 2.5 metres at 8.81% tin and 0.18% copper from 330.0 metres;
  • A13-11: 16.2 metres at 1.03% tin and 0.67% copper from 328.0 metres depth, including 2.0 metres at 4.8% tin and 2.1% copper from 330 metres;
  • A13-12A: 30.8 metres at 0.54% tin and 0.17% copper from 326 metres depth, including 2.0 metres at 2.5% tin and 0.2% copper from 326 metres depth;
  • A13-01: 76.0 metres at 0.21 % tin and 0.36% copper from 276 metres depth, including 8 metres at 0.94% tin and 0.43% copper;
  • CDD46: 10.5 metres at 0.82 % tin and 0.10 % copper from 252.0 metres depth.