Introduction

Regional Geology

Southeast Zone lithology

Southeast Zone Veining

Mineralization Southeast Zone Conclusions and future work

Acknowledgments

Blackwell, J., Black, E. and Skinner, T. (2012): National Instrument 43-101 Technical Report on 2011 Activities on the Woodjam North Property, Cariboo Mining Division, British Columbia, 134 pages.

Holliday, J.R., Wilson, A.J., Blevin, P.L., Tedder, I.J., Dunham, P.D., and P�tzner, M. (2002): Porphyry gold-copper mineralization in the Cadia district, eastern Lachlan fold belt, New South Wales and its relationship to shoshonitic magmatism: Mineralium Deposita, v.37, p. 100-116.

Mortimer, N. (1987): The Nicola Group: Late Triassic and Early Jurassic subduction-related volcanism in British Columbia: Canadian Journal of Earth Sciences. v. 24, p. 2521-2536.

Norris, J.R., Hart, C.J.R., Tosdal, R.M. and Rees, C. (2011): Magmatic evolution, mineralization and alteration of the Red Chris copper gold porphyry de posit, north western British Columbia (NTS 104H/12W); in Geoscience BC Summary of Activities 2010, Geoscience BC, Report 2011-1, p. 33–44.

Rainbow, A. (2010): Assessment Report on 2010 Activities on the Woodjam South Property including Soil Sampling, Surface Rock Sampling and Diamond Drilling; submitted by Gold Fields Horse�y Exploration Corporation, BC Ministry of Energy and Mines, AR32958, 1260 pages (under review).

Sherlock, R., Poos, S. and Trueman, A. (2012): National Instrument 43-101 Technical Report on 2011 Activities on the Wood-jam South Property, Cariboo Mining Division, British Columbia, 194 pages.

Schiarizza, P., Bell, K. and Bayliss, S. (2009): Geology and mineral occurrences of the Murphy Lake area, southcentral British Columbia (93A/03); in Geological Fieldwork 2008, BC Ministry of Energy, Mines and Petroleum Resources, Paper 2009-1, p. 169-188.

Scott, J. (2012): Geochemistry and Cu-Au Mineral Paragenesis of the Deerhorn Prospect: Woodjam Porphyry Cu-Au District, British Columbia, Canada: Bachelors of science with honours degree thesis, University of British Columbia Okanagan, 120 pages

Sillitoe, R.H. (2000): Gold-rich porphyry deposits: Descriptive and genetic models and their role in exploration and discovery: Reviews in Economic Geology, v. 13, p 315-345

Sillitoe R.H. (2010): Porphyry copper systems, Economic Geology, v. 105, pp. 3-41

Vaca, S. (2012): Variability in the Nicola/Takla Group basalts and implications for alkali Cu/Au porphyry prospectivity in the Quesnel terrane, British Columbia, Canada: Masters of Science thesis, University of British Columbia, 163 pages

References

Southeast Zone (Cu-Mo) and Deerhorn (Cu-Au) Porphyry Deposits: Paragenesis, Alteration and their Possible Relationships, Woodjam Property, Central British Columbia

Irene del Real 1 , Farhad Bouzari 1,Craig J.R. Hart 1, Jacqueline L. Blackwell 2, Amelia Rainbow 2, Ross Sherlock 2, Twila Skinner 2

1 Mineral Deposit Research Unit, UBC, 2 Gold Fields Canada Exploration

Dease Lake

Vancouver

Prince GeorgePrince Rupert

Stewart

Shaft CreekGalore Creek

Kerr

Kemess

Lorraine

Mt.Milligan

Gibraltar Mount Polley

AftonHighland Valley

Copper Mountain

USA

Alberta

Alexander terrane

Wrangel terrane

Stikine terrane

Cache Creek terrane

Quesnel terrane

Slide Mountain terrane

Kootenay/ Yukon Tananaterrane

Coast Plutonic Complex

Yukon

P a

c i f i

c O

c e a

n

Red Chris

Woodjam

City

Calc-alkalic deposit

Alkalic deposit

Williams Lake

N

0 300150

SCALE - KILOMETRES

Ancestral North America

1 cm 1 cm

Illite

Plg

1 cm

K-feldspar

Qz

Bt

Mg

1 cm

Ank

K-feldspar

Mg

1 cm

Illitecpy-py

1 cm

Qz-pyEp

Mg

Qz

Cpy

1 cm

Cpy

K-feldspar halo

Mo

Py

Cpydisseminated

1 cm

Qz

Anh

Cpy

QzIllite

alteration

1 cm

Qz-mg-cpy

Mg

Py-cpy-qz1 cm

Py-hem-qz

K-feldspar

Mg

1 cm

K-feldspar

Chl

Qz

Ep

Mg

1 cm

K-feldsparhalo

Fault

K-feldspar porphyry

0

100

SE11-59 SE11-36 SE11-62 SE11-24SE10-18 SE11-59 SE11-36 SE11-62 SE11-24SE10-18

Plagioclase porphyry dike

Ma�c dike

Overburden

Medium to coarse-grainedquartz monzonite

Fine-grained quartz monzonite

L e g e n d

437.7 m 433.4 m 462.4 m461.2 m

390.1 m

50 100

SCALE(m)

O V E R B U R D E N

Sections Specs:Ref. Pt. E, N 611230 m 579020 mExtents 710.9 m 402.8 mSection top, bot 940.3 m 537.5 mTolerance +/- 62.5 m

cp>>py

cp>py

cp=py

py>cp

No data

Sections Specs:Ref. Pt. E, N 611230 m 579020 mExtents 710.9 m 402.8 mSection top, bot 940.3 m 537.5 mTolerance +/- 62.5 m0

25

50

DH12-39 DH11-33

DH12-40

DH10-15 DH10-09

DH10-14

Sandstonevolcaniclastic

Plagioclase-phyricandesite volcaniclastic

Monzonite A

Monzonite D

Monzonite A inter�ngeringvolcaniclastic secuence

Monzonite D inter�ngering volcaniclastic secuence

Breccia

Plagioclase porphyrydike

Rubble

Overburden

L e g e n d

366.98 m

300.22 m

336.8 m 352.35 m

226.16 m

O V E R B U R D E N

25 50

SCALE(m)

WJ08-92

DH11-36

DH10-16

Fault

Section Specs:Ref. Pt. E,N 613160 m 5788000Extents 1418 m 805.6 mSection Top, Bot 1604 m 258.5 mTolerance +/- 28.5 m

cp>>py

cp>py

cp=py

py>cp

SE11-59 SE11-36 SE11-62 SE11-24SE10-18

O V E R B U R D E N

SE11-29Chalcopyrite and pyrite ratio

Bar graphs

Cu%

0.750.50.40.30.20.1

Mo ppm

100050025010010

50

100

50 100

SCALE(m)

Fault

00.5 1020

040

060

080

010

00

50 m

100

150

200

250

300

350

400

450

00.5 11.5 2

00.5 11.5

00.5 11.5

02 00

4 00

6 00

8 00

1 000

0200

400

600

800

1000

0200

400

600

800

1000

50 m

100

150

200

250

300

350

50 m

100

150

200

250

300

350

400

50 m

100

150

200

250

300

350

400

00.5 11.5 2

0 0.5 1 1.5 2

0200

4 00

6 00

8 00

1 00 0

0200

400

50 m

100

150

200

250

300

350

400

50 m

100

150

200

250

300

350

400

450

390.1 m

437.7 m 433.4 m

404.2 m

462.4 m461.2 m

The Woodjam property (93A/013, 93A/014, 93A/023, 93A/024, 93A/025, 93A/033, 93A/034, 93A/035), is part of the porphyry deposits of Late Triassic to Middle Jurassic age (216 to 183 Ma) locat-ed in the Quesnel terrane in central British Columbia. It hosts several discrete porphyry deposits including the Megabuck (Cu-Au), Deerhorn (Cu-Au), Takom (Cu-Au), Southeast Zone (Cu-Mo) and the recently discovered Three Firs (Cu-Au). These deposits display various styles and assemblages of alter-ation and mineralization. Whereas the Southeast Zone (SEZ) is compa-rable to calc-alkalic porphyry de-posits, the nearby Deerhorn zone is mainly associated with alkalic por-phyry intrusions.

The Nicola Group (host of the Deerhorn Zone)Late Triassic and Early Jurassic island arc volcanic and sedimentary strata, that is composed of submarine basaltic to andesitic augite ± plagioclase - phyric lavas, volcaniclastics and sedimentary units (Mortimer, 1987; Schiarizza et al., 2009; Vaca, 2012). This sequence extends throughout south-central British Co-lumbia.

Takomkane batholith (host of the Southeast Zone deposit)

A large composite calc-al-kalic batholith, of largely granitoid composition with a surface expression of approximately 40 × 50km, intrudes the Nicola Group. The Woodjam Creek unit of the Takom-kane batholith occurs in the Woodjam district and is composed of granodio-rite, monzogranite and quartz-monzonite (Schiarizza et al., 2009).

Nicola and Takomkane units are overlain by the Early Miocene to Early Pleistocene basalt of the Chilcotin Group.

Geoscience BC is acknowledged and thanked for the funding pro-vided for this project. Gold Fields Canada and Consolidated Wood-jam Copper Corporation is thanked for funding and �eld support for the project. The entire sta�s of the Woodjam project, including Julia Scott, Mark McKenzie, Shawn Vanderkekhove, Katherine Rempel and Matt Eckfeldt are thanked for their support during the �eld work.

Recent exploration at the Deerhorn Cu-Au deposit has shown two contrasting alter-ation assemblages of K-feldspar + magne-tite, typical of alkalic systems, and illite+ tourmaline and Mo mineralization typical of calc-alkalic system. The SEZ displays some features not typical of calc-alkalic de-posits such a very low amount of quartz veining.

These observations suggest a temporal and paragenetic relationship between the two deposits may exist, thus providing a unique opportunity to study the relationship be-tween alkalic and calc-alkalic deposits in BC.

- Hosted by a series of texturally variable quartz monzonite intrusive bodies divided texturally into �ne, medium

and coarse grained units (Rainbow, 2010). All quartz monzonites are intruded by K-feldspar porphyry body.

- Quartz monzonites were emplaced pre- to syn- mineralization and are a�ected by intense alteration, whereas

the K-feldspar porphyry was probably emplaced during the �nal stages of hydrothermal activity (Rainbow, 2010;

Sherlock et al., 2012).

- Nicola Group stratigraphy consists of volcaniclastic sandstone, overlain by a plagioclase-phyric andesite

with local clast breccia facies (Blackwell et al., 2012).

- “Monzonite A” occurs as “pencil” shaped intrusive bodies, which intrude the volcano-sedimentary rocks of

the Nicola Group (Blackwell et al., 2012).

- “Monzonite D” is characterized by plagioclase and hornblende phenocrysts and occurs as dikes with sharp

contact that cross-cut Monzonite A and Nicola Group stratigraphy (Blackwell et al., 2012).

Coarse quartz monzonite Medium quartz monzonite Fine quartz monzonite K-feldspar porphyry Plagioclase porphyry dike

Sandstone volcaniclasticPlagioclase-phyric

andesite volcaniclastic Monzonite A Monzonite D

Deerhorn Zone lithology

- K-feldspar + biotite + magnetite is the earliest alteration, occurs as pervasive mineral

replacement

- Albite alteration is recognized at the northern extent of the deposit

- Chlorite ± epidote ± pyrite intensity is higher at the margins of the deposit.

- Illite occurs as three visually and possibly paragenetically distinct types: dark green illite,

white illite and apple-green illite.

- K-feldspar + biotite + magnetite alteration is very intense in Monzonite A and in the

volcanic rocks surrounding these intrusions.

- Chlorite ± epidote ± pyrite alteration occurs mainly in Monzonite D and in the sur-

rounding volcanic host rocks.

- Ankerite and calcite veinlets occur throughout all lithologies.

- Illite occurs mainly as vein envelope overprinting vein K-feldspar halos

Alteration Southeast Zone

Intense K-feldspar+biotite+magnetitealteration in coarse grained monzonite

Intense albite alteration of �negrained quartz monzonite

Apple green illite alteration overprinting albite and k-feldspar+biotite+magnetite alteration

in �ne grained quartz monzonite

intense K-feldspar+biotite+magnetitealteration in the volcanic host rock

near contact with Monzonite A

epidote and quartz-pyritevein in the andesite volcaniclastic

host rockillite vein envelope of chalcopyrite stringer

in Monzonite D

- Rare magnetite stringers and quartz ± chalcopyrite ± magnetite veins occur locally

in the core of the porphyry.

- Quartz ± chalcopyrite ± pyrite ± molybdenite ± anhydrite (±bornite) veins with

K-feldspar halos occur in the deep central and marginal areas.

- Pyrite ± epidote ± chlorite veins with epidote ± hematite ± illite halos occur com-

monly at the margins of the deposit.

- Magnetite stockwork and gold bearing quartz-magnetite ± hematite ± sulphide

veins occur in Monzonite A and adjacent the volcanic host rocks.

- Quartz-magnetite-chlorite–K-feldspar veins occur in the volcanic host rock.

- Pyrite –quartz ± hematite ± epidote ± tourmaline veins with a white illite halo occur

throughout all rock units as well as pyrite – chlorite ± calcite ± ankerite veins.

Quartz-magnetite-chalcopyrite veiningwith very intense K-feldspar-biotite-magnetitealteration in coarse grained quartz monzonite

Quartz-chalcopyrite-molybdenite-pyrite vein with k-feldspar halo in medium coarse

grained quartz monzonite

Quartz-chalcopyrite-anhydrite centerlinevein, with selective replacement of

plagioclase by illite

Quartz-magnetite-chalcopyrite and magnetite veinlets are cut by a pyrite-chalcopyrite-quartz vein

Quartz-magnetite-chlorite-K-feldspar veinwith K-feldspar halo in the

volcaniclastic sandstone

K-feldspar vein cut magnetite veinwhich is itself cut by

pyrite-quartz-hematite vein

- Copper occurs dominantly in chalcopyrite with subordinate bornite as disseminations and more com-

monly in veins.

- Molybdenite is mainly observed in veins.

- Areas of high copper grades (ca. 0.5% Cu) are characterized by dense stockworks of thin veins and with

abundant disseminated chalcopyrite in the host-rock.

- Sulphide zoning at SEZ consists of chalcopyrite ± bornite (±pyrite) assemblage in the core of the deposit

which changes upward and outward to chalcopyrite ± molybdenite ± pyrite and �nally a pyrite dominated

assemblage in the periphery of the deposit.

- Has signi�cantly higher Au grades than the SEZ, that are associated with Cu mineralization (up to ≤1.5

ppm Au and <0.75% Cu).

- Mineralization is hosted dominantly in Monzonite A and the adjacent volcanic host rocks and occurs as dis-

seminated, in the early quartz-magnetite-chalcopyrite veins and in later quartz-sulphide veins.

- Monzonite D hosts lower grades of copper mineralization (~0.1-0.3% Cu) but does not host signi�cant gold.

Trace amounts of molybdenite have been observed in the later-stage quartz sulphides veins in Monzonite D.

- Sulphide ratios in the deposit depend of the lithology, consisting of higher cpy:py ratio in Monzonite A and

lower in Monzonite D and the volcanic host rock.

Tourmaline alteration in hole DH10-09, in monzonite D in the Deerhorn deposit

The SEZ deposit presents mainly calc-alkalic charac-teristics. However the low abundance of quartz vein-ing is not a typical feature of this type of deposit.

The K-feldspar +/- biotite +/- magnetite alteration assemblage and the vein stages observed at the Deer-horn deposit, illite+ tourmaline and Mo mineralization are consistent with characteristics of Cu-Au and Cu-Mo calc-alkalic porphyry systems (Sillitoe, 2000; Sil-litoe 2010); however, the “pencil” shape intrusive host rock lacking modal quartz is consistent with character-istics of Cu-Au alkalic porphyry systems (Holliday et al., 2002).

The close proximity as well as the similar alteration and vein stages at the SEZ and Deerhorn deposits sug-gest that they could be related and may represent a transition from the alkalic to calc-alkalic environment.At the Deerhorn zone Monzonite D hosts Cu-Mo min-eralization similar to that of the SEZ, suggesting also that alkalic-stage (in Monzonite A) occurs �rst and the calc-alkalic stage occurs second.

The next stage of this project will focus on the geo-chemistry and magmatic-hydrothermal evolution of these deposits in the Woodjam district, using detailed petrography and geochemical analyses.

Mineralization Deerhorn Zone

Major tectonic terranes and associated porphyry deposits of the Canadian Cordillera in British Columbia

(modi�ed from McMillan et al., 1995)

View from the Southeast zone deposit

Geological map of the Woodjam district. Cross section line of drill holes relogged in this study are shown (red lines) for Southeast zone (a)

and Deerhorn (b) deposits (from Gold Fields Exploration Canada, internal data 2012)

Alteration Deerhorn Zone

Deerhorn Zone Veining

tourmaline

1 cm

chalcopyrite

pyrite

Molybdenite

Chalcopyrite

Pyrite

Pyrite-chalcopyrite-molybdenite-quartz vein in hole DH10-09 in monzonite D, in the Deerhorn deposit

100 µm

Section Specs:Ref. Pt. E,N 613160 m 5788000Extents 1418 m 805.6 mSection Top, Bottom 1604 m 258.5 mTolerance +/- 28.5 m

Lithology from holes DH10-15, WJ08-92 and DH10-16 was logged by Gold Fields pers. comm. 2012

Cp:py ratios of hole SE11-29, and Cu-Mo grades of all holes where given by Gold Fields pers. comm. 2012

1 cm 1 cm 1 cm 1 cm1 cm

1 cm 1 cm 1 cm 1 cm

cp=py=0

Deerhorn deposit

DH12-40

DH11-36

DH12-39 DH11-33DH10-15 DH10-09

DH10-14DH10-16

o v e r b u r d e n

0

25

50

25

SCALE(m)

50

Cp:py ratios of hole DH10-16 and DH11-36 and Cu-Au grades of all holes where given by Gold Fields pers. comm. 2012

Cu%

0.750.50.40.30.20.1

Au ppm

1.510.750.250.1

Bar graphs

Chalcopyrite and pyrite ratio