Deep Environment

Elevation of Highest Grade Cu

Top of Mineralized Zone

1 km

1 km

1 km

graniteporphyry

dikes

Deep Environment

Elevation of Highest Grade Cu

Top of Mineralized Zone

1 km

1 km

1 km

magmatic uids

0 1 2 3 4 5 6

700

100

200

300

400

500

600

log (mKCl + K+/mHCl + H+)

TC

? ?

?

? ?

2195

2210

2200

2220

white mica 2200 nm wavelength

Kaolinite

Pyrophyllite

Andalusite

Muscovite

K-feldspar

(Dickite kaolinite)

(Dickite pyrophyllite) Illite

Smectite

Phengite

Act+Epid

Chl+Epid

ChlHem Calc

mixed layer Chl-Smect

Kspar - Biot (Potassic)

SericiticAdvanced Argillic

Intermediate Argillic

Propylitic

Ilite-Smectite

500 b

2 kb

1 kb

System K2O-Al2O3-SiO2-KCl-HCl-H2O at 1.0 kb,

quartz present(Hemley et al.,1980; Montoya & Hemley, 1975; Sverjensky et al., 1991; Hazelton et al., 1994; Reyes, 1990)

PyCpSlGa

Cp-Py

CpBn

spec. hematite

PyCpSlGa

Cp-Py

CpBn

Cu > 0.2wt% (MoAu)

2210 nm

2200 nm2205 nm

Wavelength of white mica SWIR (2200)

Illite-chl-smect-relic fspar

epid-chl-act-fspar

plag-actepid

chl-fsparcalc/epid-hem

biotKspar

smectIllitekaolchl& relic feldspar

Illite-chl-relic fspar

phengiticmusc-chl-relic fspar musc

pyroph-aluntopaz

SODIC-CALCIC

PROPYLITIC

POTASSIC

SERICITIC

non-magm

atic uids

Na, Ca, and Sr enrichment,K, Fe, Mn, V, Pb, Zn, Cs, Cu depletion

MoBi, Se, Te halo

Localized Tl, As, Bi

Depletion in As, Mn, Pb, Zn,

Cs, Sb, Tl in K silicate core

MoBi, Se, Te

Outer Zn, Pb, Mnelevated compared

to core

Mo +Bi-Se-Te

Increasing Tl, As, Bi,

Se, TeLi, Zn, V

elevated compared to core

Lateral distribution of elements

SODIC-CALCIC

PROPYLITIC

ADVANCEDARGILLIC

LATE INTERMEDIATEARGILLIC

POTASSIC

INTERMEDIATEARGILLIC

SERICITICPHYLLIC

Return tobackgroundZn, Mn, Sr, Co, Ni, Li

granite porphyry dikes

+Li > 15 ppm+Tl > 1.5 ppm

+Sb > 4 ppm; As > 50 ppm

+Se > 4 ppm

+Te > 1 ppm

+Bi > 1 ppm

+Sn > 4 ppm+W > 5 ppm

Mo > 5 ppm

+Cu >0.1 wt%

Explanation

Flow path of external fluid

Added

Depleted

+-

zone of magm

atic hyd rothermal alteration

Flow path of magmatic-derived fluid

Return tobackgroundZn, Mn, Sr, Co, Ni, Li

Vertical distribution of elements

Typical Pathfinder Ranges (ppm)Potassic Deep Phyllic Shallow Phyllic

Cu >200 100 50Mn below background 1000 - 5000 400 - 1000Se 5 - 20 1 1Mo 0.5 to ore grade 2 - 20 0.5 - 5Te 0.1 1 - 5 0.1 - 1Bi 0.05 1 - 10 0.05 - 1Zn below background 200 - 1000 10 - 100Pb 50 200 - 1000 10 - 100Ag 0.5 to 3 1 to 50 1 to 10As below background 10 to 50 50 to 1000Sb below background 1 to 3 3 to 100Tl 0.2 0.2 1 to 50Hg 0.05 0.05 0.2 to 10

-Zn, Mn,Co, Ni, Sr, Pb, As, Tl, Cs, Rb, Li

+ Na, Ca, Sr-Fe, K, Cu , Zn, Mn, Co, Ni,

+ Na, Ca, Sr-Fe, K, Cu , Zn, Mn, Co, Ni,

John H. Dilles, Scott W. Halley, Richard M. Tosdal

Geochemical and mineralogic footprint of a porphyry Cu (-Mo-Au) system