This file is part of the following reference:

New, Brian (2006) Controls of copper and gold distribution in the Kucing Liar deposit, Ertsberg mining district, West Papua, Indonesia.

PhD thesis, James Cook University.

Access to this file is available from:

http://eprints.jcu.edu.au/2083

Controls of copper and gold distribution in

the Kucing Liar deposit, Ertsberg Mining

District, West Papua, Indonesia

B.T.E. New

Thesis submitted by Brian New BSc(Hon.) Nvember 2006

For the degree of Doctor of Philosophy (PhD.),

School of Earth Sciences, James Cook University, Australia

ii Kucing Liar, Ertsberg mining district __________________________________________________________________________

Tembagapura

The “copper town” of Tembagapura is built on glacial sediments in a deeply incised valley. The town receives 8m of rain per year on average. The smaller barracks of Hidden Valley is visible at upper right and is where drill core was housed.

Mt Zaagkham

Mt Zaagkham as viewed from the core shed where drill core samples were investigated. This very impressive mountain is generally only visible in the morning before cloud cover and accompanying rain sets in for the afternoon.

iii

__________________________________________________________________________

Statement of Access

I, the undersigned, the author of this thesis, understand that James Cook University will make

it available for use within the university library and, by microfilm or other means, allow

access to users of other approved libraries.

All users consulting this thesis by either hardcopy or digital means will have to sign the

following statement:

“In consulting this thesis I agree not to copy or closely paraphrase it in while or in part

without the written consent of the author; and to make proper public written knowledge for

any assistance which I have obtained from it”

The assay data made available for every drill hole in the Kucing Liar resource delineation by

PT Freeport Indonesia for this research and the results of their analysis are included.

However, due to the economic sensitivity of the project, the full data set is not included in this

volume.

Beyond this I do not wish to place any restriction on access to this thesis.

Brian New

November 2006

iv Kucing Liar, Ertsberg mining district __________________________________________________________________________

Declaration

I declare that this thesis is my own work and has not been submitted in any form for another

degree or diploma at any other university or institution of tertiary education. Where analytical

work has been completed by others they have been acknowledged. Information derived from

the published or unpublished work of other has been acknowledged in the text and a list of

these references is supplied.

Brian New

November 2006

v

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Acknowledgements

This research topic was originally conceived by Roger Taylor and Peter Pollard (James Cook

University) and was initiated by Chuck Brannon for PT Freeport Indonesia. Steve van Nort

and George Macdonald of PT Freeport Indonesia provided continued support. The company

supplied transport, accommodation and provisions for multiple field visits to the mine site in

addition to funds for all analytical requirements and a living allowance for a three year period.

This generous financial assistance to research is gratefully recognized. Staff at the mine site

who have assisted this research by way of many discussions include Peter Manning, Nur

Wiwoho and Sugeng Widodo as well as Bowo Kusnanto and Noris del bel Belluz. Detailed

regional and local map material was kindly provided by Keith Parris. Uttu Mekiel and Aris

Sitohang continuously provided logistical assistance for drill core examination.

The (numerous) drafts, commonly unfinished, and final manuscript were assessed by Pat

Williams and his assistance in thesis compilation was much appreciated. Additional

comments and suggestions for improvements were also provided by Roger Taylor and Peter

Pollard. I would like to thank Roger and Peter for their invaluable teaching and friendship. I

would also like to extend thanks to long-standing staff of the School, Mike Rubenach, Bob

Henderson, Tim Bell and more recently Pat Williams, Nick Oliver and Tim Baker for the

enjoyable education I have received over the many years I have spent at JCU. Darren Mylrea,

Sharon Ness and Kevin Blake from the Advanced Analytical Centre at JCU provided much

appreciated analytical support for sample preparation for geochronology and isotope analysis

as well as XRD and SEM analyses and interpretations.

Finally I would like to thank my family for continued support and all the friends I have

accumulated while studying at JCU from 1988-2006.

vi Kucing Liar, Ertsberg mining district __________________________________________________________________________

Mineral Abbreviations

Ah Anhydrite

Bn Bornite

Bt Biotite

Bp Brown phlogopite

Cc Calcite

Cp Chalcopyrite

Cpx Clinopyroxene

Cspy Coarse pyrite

Ct Chalcocite

Cv Covellite

Cy Chrysotile

Dg Digenite

Do Dolomite

En Enargite

Fnpy Fine pyrite

Fo Forsterite

Gl Galena

Gp Green phlogopite

Gt Garnet

Hb Hornblende

Hu Humite

Kf K-feldspar

Mo Molybdenite

Ms Muscovite

Mt Magnetite

Nk Nukundamite

Pl Plagioclase

Po Pyrrhotite

Py Pyrite

Qz Quartz

Se Serpentine

Tl Talc

Tr Tremolite-actinolite

Sp Sphalerite

vii

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Table of Contents

1. INTRODUCTION

2. HOST ROCKS

3. PARAGENESIS

4. STRUCTURAL SETTING AND FLUID FLOW

1.1 Regional and local setting ____________________________________________ 5

1.1.1 Geology of New Guinea and the Southern Central Ranges ____________________ 5

Tectonic evolution of New Guinea _____________________________________________________ 6 Stratigraphy and structure of the Southern Central Ranges _________________________________ 9

1.1.2 Geology of the Ertsberg Mining District __________________________________ 12

1.2 Access and methods ________________________________________________ 15

1.2.1 Physiography of the mining district ______________________________________ 15

1.2.2 Sources of data ______________________________________________________ 18

2.1 Previous work and sources of data ____________________________________ 24

2.1.1 Regional stratigraphic sequence ________________________________________ 24

2.1.2 District outcrop and deep drilling _______________________________________ 27

2.2 Results ___________________________________________________________ 31

2.2.1 Descriptions of local unaltered lithological sequences ______________________ 32

2.2.2 Textures developed in low-intensity distal alteration _______________________ 40

3.1 Mineral textures, assemblages and timing relationships __________________ 48

Group I paragenesis ________________________________________________________________ 48

Group II __________________________________________________________________________ 58

Group III _________________________________________________________________________ 62

Group IV _________________________________________________________________________ 66

Intrusive rocks ____________________________________________________________________ 72

3.2 Interpretation of Kucing Liar paragenesis _______________________________ 74

Classification and inter-relationships of Kucing Liar mineral assemblages _____________________ 74

Petrologically defined conditions of the Kucing Liar hydrothermal system _____________________ 80

4.1 Stratigraphic and fluid flow modelling _________________________________ 83

4.1.1 Lithological distribution _______________________________________________ 83

Stratigraphic sequence recognition ____________________________________________________ 83

Large-scale geometry _______________________________________________________________ 89

4.1.2 Hydrothermal mineral distribution ______________________________________ 95

Patterns of hydrothermal alteration ___________________________________________________ 95

Large-scale mineral distributions ______________________________________________________ 99

4.2 Large-scale controls on fluid infiltration _______________________________ 106

4.2.1 Structural geometry of Kucing Liar alteration _____________________________ 106

4.2.2 Driving forces of fluid flow ____________________________________________ 108

viii Kucing Liar, Ertsberg mining district __________________________________________________________________________

Table of Contents (cont.)

5. ORE MINERAL DISTRIBUTION AND METAL ZONING

6. FLUID INCLUSION STUDIES

7. STABLE ISOTOPE GEOCHEMISTRY

5.1 Mineralisation populations and spatial distributions ____________________ 111

5.1.1 Spatial models of ore mineral and metal distributions _____________________ 111

Metal distributions relative to the structural setting _____________________________________ 111

Elevation patterns of metals and ore minerals __________________________________________ 127

5.1.2 Inter-element associations ___________________________________________ 131

Copper-gold relationships __________________________________________________________ 133

Trace metal relationships ___________________________________________________________ 138

5.2 Interpretation of metal assay data ___________________________________ 143

5.2.1 Defining the mineralisation process through metal associations _____________ 143

Styles of mineralisation ____________________________________________________________ 143

Zoning patterns __________________________________________________________________ 144

5.2.2 Metal complexes and ore precipitation _________________________________ 145

6.1 Fluid inclusion petrography _________________________________________ 149

6.1.1 Sample location and descriptions ______________________________________ 149

6.1.2 Occurrence and paragenesis __________________________________________ 154

6.2 Thermometric experiments _________________________________________ 159

6.2.1 Results of freezing and heating ________________________________________ 159

Solid phase melting temperatures____________________________________________________ 160

Vapour homogenisation ____________________________________________________________ 163

6.2.2 Determination of fluid composition ____________________________________ 167

Salt system ______________________________________________________________________ 167

Salinity calculations _______________________________________________________________ 168

6.3 Interpretation of fluid inclusion data _________________________________ 170

6.3.1 Fluid populations ___________________________________________________ 170

6.3.2 Fluid phase development _____________________________________________ 171

7.1 Isotopic analyses _________________________________________________ 176

7.1.1 Results of analyses __________________________________________________ 176

7.1.2 Fluid compositions __________________________________________________ 181

Results of fractionation calculations __________________________________________________ 187

7.2 Interpretation ____________________________________________________ 189

Fluid reservoirs and isotopic compositions _____________________________________________ 189

Magmatic exsolution processes ______________________________________________________ 192

ix

__________________________________________________________________________

Table of Contents (cont.)

8. 40

AR/39

AR AND RE-OS GEOCHRONOLOGY

9. DISCUSSION

8.1 Sample collection _________________________________________________ 195

8.2 Age spectra and results from analyses ________________________________ 199

8.3 Interpretation of age data __________________________________________ 208

Interpretation of Kucing Liar age data _________________________________________________ 208

Geochronology of the Ertsberg Mining District _________________________________________ 209

9.1 Tectonic-magmatic setting of fluid infiltration __________________________ 214

9.1.1 Tectonic transition and porphyry emplacement___________________________ 214

9.1.2 Progressive deformation and structural geometry _________________________ 217

9.2 Fluid evolution leading to hydrothermal mineralization __________________ 223

9.2.1 The collapse of magmatic-hydrothermal systems _________________________ 223

9.2.2 Effect of fluid mixing on ore chemistry __________________________________ 224

9.3 Kucing Liar in the continuum of porphyry-related ore systems _____________ 227

9.3.1 Classification of porphyry-epithermal ores _______________________________ 227

9.3.2 Juxtaposition of porphyry-epithermal systems ___________________________ 230

9.4 Concluding remarks _______________________________________________ 233

x Kucing Liar, Ertsberg mining district __________________________________________________________________________

List of Figures

Figure 1-1 Distribution of porphyry Cu±Mo±Au deposits in the circum-Pacific region _________________ 1

Figure 1-2 Ore deposit environments related to porphyritic intrusions _____________________________ 2 Figure 1-3 Location of the Ertsberg Mining District ____________________________________________ 3 Figure 1-4 Physiography of Irian Jaya and Papua New Guinea ___________________________________ 5 Figure 1-5 Palimspastic reconstruction of the evolution of New Guinea ____________________________ 7

Figure 1-6 Tectonics and igneous intrusions of New Guinea (reproduced from McDowell et al., 1996) ____ 8 Figure 1-7 Sedimentary record of the Timika-Tembagapura region (reproduced from Parris, 1994a). ___ 10 Figure 1-8 Geology of southern flanks of the Central Range ____________________________________ 11 Figure 1-9 Geological map of the Ertsberg Mining District (supplied by PT Freeport Indonesia) ________ 14

Figure 1-10 Physiography of the Southern Ranges and Ertsberg Mining District ____________________ 16 Figure 1-11 Position of Kucing Liar mineralisation relative to Grasberg Igenous Complex _____________ 19 Figure 1-12 Plan view of all Kucing Liar drill traces logged for this research program ________________ 20 Figure 1-13 Layout of all holes in each drill station logged for this research program ________________ 21 Figure 2-1 Plan projection showing collar locations for stratigraphical drillholes ____________________ 30

Figure 2-2 Lithology and composition of unmineralised stratigraphy _____________________________ 31 Figure 3-1 Example of GADDS X-ray diffraction identification of hornfels alteration in shale___________ 50

Figure 3-2 Composition of clinopyroxene and feldspar _________________________________________ 51

Figure 3-3 Composition of garnet _________________________________________________________ 52

Figure 3-4 Example of GADDS X-ray diffraction identification of a humite group mineral _____________ 55

Figure 4-1 Stratigraphic patterns identified in drilling _________________________________________ 88

Figure 4-2 Serial sections of Kucing Liar lithology (refer Chapter 1 for section locations) ______________ 90

Figure 4-3 Interpretative cross sections of Kucing Liar stratigraphy from wireframes ________________ 92

Figure 4-4 Interpretative plan sections of Kucing Liar stratigraphy from wireframes _________________ 93

Figure 4-5 Interpretative longitudinal sections of Kucing Liar stratigraphy from wireframes ___________ 94

Figure 4-6 Lithological patterns and mineral abundances in representative drill holes _______________ 96

Figure 4-7 Distribution of calcite, clinopyroxene, garnet, humite and phlogopite ___________________ 101

Figure 4-8 Distribution of dominant K-feldspar + biotite alteration ______________________________ 102

Figure 4-9 Distribution of extensive magnetite and tremolite-actinolite alteration _________________ 103

Figure 4-10 Distribution of rocks dominated by quartz, muscovite and anhydrite alteration __________ 104

Figure 4-11 Distribution of ore sulphides, pyrite, chalcopyrite and covellite _______________________ 105

Figure 5-1 Downhole distribution of metal concentrations ____________________________________ 113

Figure 5-2 Spatial distribution and structural controls of pyrite alteration ________________________ 117

Figure 5-3 Spatial distribution and structural controls of chalcopyrite ___________________________ 118

Figure 5-4 Spatial distribution and structural controls of covellite _______________________________ 119

Figure 5-5 Spatial distribution and structural controls of copper ________________________________ 120

Figure 5-6 Spatial distribution and structural controls of zinc __________________________________ 121

Figure 5-7 Spatial distribution and structural controls of lead __________________________________ 122

Figure 5-8 Spatial distribution and structural controls of gold __________________________________ 123

Figure 5-9 Spatial distribution and structural controls of silver _________________________________ 124

Figure 5-10 Spatial distribution and structural controls of arsenic _______________________________ 125

Figure 5-11 Spatial distribution and structural controls of antimony _____________________________ 126

Figure 5-12 Variation of average copper and gold grades relative to elevation ____________________ 127

Figure 5-13 Elevation variations of Ag-Zn-Pb and As-Sb relative to Cu-Au ________________________ 128

Figure 5-14 Characteristics of chalcopyrite and covellite-bearing ore relative to elevation ___________ 129

Figure 5-15 Distribution of copper, gold and sulphur phases relative to elevation __________________ 130

Figure 5-16 Global relationship of copper and gold __________________________________________ 132

Figure 5-17 Copper and gold distributions in assay populations classified by logged copper sulphide species

____________________________________________________________________________________ 134

Figure 5-18 Cu-Au grades of assay intervals dominated by various paragenetic associations _________ 135

Figure 5-19 Copper and gold grade distributions in populations classified by dominant paragenetic stage in

assay interval ________________________________________________________________________ 136

Figure 5-20 Minor element variations with respect to copper __________________________________ 139

Figure 5-21 Minor element variations of the low-Cu ore sample population with respect to gold ______ 140

xi

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List of Figures (cont.)

Figure 5-21 Minor element variations of the low-Cu ore sample population with respect to gold ______ 140

Figure 5-22 Correlation coefficients for signficant sample populations in Kucing Liar _______________ 142

Figure 5-23 Zoning of ore sulphides, pyrite, chalcopyite and covellite and Cu-Au-As ________________ 147

Figure 6-1 Location of fluid inclusion samples _______________________________________________ 151

Figure 6-2 First melt (eutectic) and final melting temperatures of ice in frozen inclusions ____________ 161

Figure 6-3 Final melting temperatures of halite and sylvite in fluid inclusions _____________________ 162

Figure 6-4 Final homogenisation temperature versus ice melting temperatures ___________________ 164

Figure 6-5 Vapour homogenisation versus salt melting temperatures in SLV-type inclusions _________ 166

Figure 6-6 Final homogenisation temperatures of fluid inclusions _______________________________ 166

Figure 6-7 Homogenisation temperature versus calculated salinities of fluid inclusions _____________ 169

Figure 6-8 Homogenisation temperatures of fluid inclusions ___________________________________ 173

Figure 6-9 Bulk salinity of magmatic fluids exsolved from water saturated magmas ________________ 174

Figure 6-10 Phase separation of critical magmatic fluid (from Meinert, 1998) _____________________ 174

Figure 7-1 Histograms showing analysed oxygen, hydrogen and sulphur isotope ratios _____________ 180

Figure 7-2 Fractionation curves for oxygen (a-d), hydrogen (e) and sulphur (f) ____________________ 185

Figure 7-3 Histograms showing calculated oxygen, hydrogen and sulphur isotope ratios ____________ 188

Figure 7-4 Calculated δ18

OFLUID for the Kucing Liar paragenesis _________________________________ 191

Figure 7-5 Calculated Hydrogen and oxygen isotope compositions of Kucing Liar fluids _____________ 193

Figure 8-1 Grainsize of muscovite crystals __________________________________________________ 197

Figure 8-2 Photographs of geochronology samples __________________________________________ 198

Figure 8-3 Age spectra and isochron plots of sample KL28-1 360.3m (green phlogopite) ____________ 200

Figure 8-4 Age spectra and isochron plots of sample KL32-8 331.0m (green phlogopite) ____________ 201

Figure 8-5 Age spectra and isochron plots of sample KL32-5 539.6m ( brown biotite) _______________ 202

Figure 8-6 Age spectra and isochron plots of sample KL32-5 652.4m (brown biotite) _______________ 203

Figure 8-7 Age spectra and isochron plots of sample KL32-5 465.3m (brown biotite) _______________ 204

Figure 8-8 Age spectra and isochron plots of sample KL32-8 455.9m (muscovite) __________________ 205

Figure 8-9 Age spectra and isochron plots of sample KL32-1 255.7m (muscovite) __________________ 206

Figure 8-10 Absolute ages of hydrothermal minerals and their accuracies ________________________ 207

Figure 8-11 Geochronology of the Ertsberg Mining District ____________________________________ 211

Figure 9-1 Analogue model of deformation front for various convergence angles __________________ 216

Figure 9-2 Geometry and structural detail of fault jogs _______________________________________ 220

Figure 9-3 Naming convention for structures present in a left lateral fault-slip system ______________ 220

Figure 9-4 Geometric characteristics of strike-slip faults ______________________________________ 221

Figure 9-5 Speculative models for development of structral offset in Idenberg Fault Zone ___________ 222

Figure 9-6 Generalised model of porphyry-related ore systems _________________________________ 229

Figure 9-7 Plot of log fs2 – Temperature for fluids in porphyry systems ___________________________ 230

Figure 9-8 Telescoping of epithermal systems into porphyry environment ________________________ 232

xii Kucing Liar, Ertsberg mining district __________________________________________________________________________

List of Plates

Plate 1-1 Relief of the Ertsberg Mining District and access routes ________________________________ 17 Plate 2-1 Large-scale exposure of host stratigraphy ___________________________________________ 28

Plate 2-2 Examples of Ekmai Sandstone and limestone ________________________________________ 33

Plate 2-3 Outcrop of the Waripi Limestone __________________________________________________ 34

Plate 2-4 Examples of Waripi Limestone visible textures _______________________________________ 36

Plate 2-5 Examples of Faumai Limestone visible and micro-textures ______________________________ 38

Plate 2-6 Example of Sirga Sandstone ______________________________________________________ 39

Plate 2-7 Example of Kais Limestone _______________________________________________________ 39

Plate 2-8 Examples of dolomitisation textures _______________________________________________ 41

Plate 2-9 Examples of dolomitisation micro-textures in peloid limestone __________________________ 42

Plate 2-10 Examples of dolomitisation micro-textures in foraminiferal limestone ___________________ 43

Plate 2-11 Examples of distal hydrothermal alteration ________________________________________ 45

Plate 2-12 An axample of hydrothermal micro-textures in sandstone _____________________________ 46

Plate 3-1 Textures and timing relationships of anhydrous Group I minerals ________________________ 53

Plate 3-2 Textures and timing relationships of hydrous Group I minerals __________________________ 57

Plate 3-3 Textures and relative timing of potassic Group II minerals ______________________________ 60

Plate 3-4 Textures and relative timing of non-potassic Group II minerals __________________________ 62

Plate 3-5 Textures and timing relationships of Group III minerals ________________________________ 65

Plate 3-6 Textures and timing relationships of pyrite, pyrrhotite and chalcopyrite ___________________ 68

Plate 3-7 Textures and relative timing of covellite, enargite and nukundamite _____________________ 70

Plate 3-8 Textures and timing relationships of galena, sphalerite and molybdenite __________________ 71

Plate 3-9 Visible and microscopic textures of common alteration effects in monzonite _______________ 73

Plate 3-10 Visible and microscopic textures of diorite _________________________________________ 73

Plate 4-1 An example of lithological sequence commonly found in faulted regions __________________ 87

Plate 6-1 Photographs of wafers and blocks of fluid inclusion samples ___________________________ 152

Plate 6-2 Photomicrographs of textural settings of crystals that host fluid inclusions _______________ 153

Plate 6-3 Fluid inclusion types in quartz ___________________________________________________ 156

Plate 6-4 Fluid inclusion occurrences in quartz ______________________________________________ 156

Plate 6-5 Examples of fluid inclusion trails _________________________________________________ 157

Plate 6-6 Crosscutting fluid inclusion relationships ___________________________________________ 158

xiii

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List of Tables

Table 1-1 Copper and/or gold resources of the Ertsberg Mining District ____________________________ 4 Table 2-1 Descriptions of stratigraphy in the Ertsberg Mining District ____________________________ 26 Table 5-1 Average grade of mineralisation in different mineral associations ______________________ 135

Table 5-2 Average metal concentrations in assay intervals classified by copper species present _______ 141

Table 6-1 First melt temperatures of selected water-salt systems _______________________________ 167

Table 7-1 Stable isotope samples and results (‰) ___________________________________________ 178

Table 7-2 Temperatures used for calculating fluid isotope compositions _________________________ 182

Table 7-3 Mineral-H2O fractionation equations for oxygen (Temperature (T) is in Kelvin) ____________ 183

Table 7-4 Mineral-H2O fractionation equations for hydrogen (Temperature (T) is in Kelvin) __________ 184

Table 7-5 Mineral-SO4/H2S fractionation equations for sulphur (Temperature (T) is in Kelvin) ________ 184 Table 8-1 Ages and precisions for

40Ar/

39Ar methods on selected minerals ________________________ 207

Table 8-2 Geochronology of Ertsberg Mining District hydrothermal minerals ______________________ 211

Table 8-3 Geochronology of Ertsberg Mining District intrusions ________________________________ 212

Abstract

Kucing Liar is a large sediment-hosted Cu-Au mineralized system containing some 15Moz of gold and

5Mt of copper in ~500Mt of ore. It is situated in the Ertsberg Mining District in the Central Ranges of

New Guinea, in the Indonesian province of West Papua. This study demonstrates that high sulphidation

ore is continuous with typical porphyry-skarn style chalcopyrite ore and that both have formed from

mixing of magmatic with meteoric waters within a zone of fault offset.

Alteration and mineralization were localised within calcareous shale and thinly bedded limestone

adjacent to the Grasberg Igneous Complex where they are zoned around fault offsets. Early phases of

alteration are stratiform and are juxtaposed against the Idenberg Fault Zone, which has displaced host

stratigraphy at least 600m vertically and possibly up to ~1,500m laterally. Four principal hydrothermal

mineral associations are (1) calcic and magnesian skarn, (2) potassic assemblages including magnetite,

(3) quartz-muscovite plus anhydrite and (4) locally massive pyrite. Cu and Au are associated with

pyrite and occur discretely either as chalcopyrite ± bornite with an association of Cu-Au-Co (Zn-Pb) or

as covellite ± enargite associated with Cu-Au (As-Sb-Hg). 40

Ar/39

Ar geochronology shows muscovite

(3.18 ± 0.02Ma) was coeval with potassic-biotite assemblages (3.18 ± 0.02Ma and 3.20 ± 0.04Ma).

Calcic and magnesian skarn were derived from magmatic fluids (δ18

OFLUID = 9-6‰), while potassic and

magnetite alteration were derived from high temperature (>650°C), high salinity (>50wt%NaClEQUIV.)

magmatic fluids (δ18

OFLUID = 6-12‰). Quartz infill crystals associated with voluminous silicification

contain a variety of fluid inclusions that range from moderate temperature (TH<420°C) high and

moderate salinity brines (35-55 and 15-30wt%NaClEQUIV.), to low density - low salinity vapour-rich

fluid inclusions. Fluorite-hosted inclusions with lower TH (<300°C) and salinity (~5wt%NaClEQUIV.) are

also related to quartz alteration. Quartz alteration, muscovite and anhydrite have estimated δ18

OFLUID

ranging from 0-6‰. δD data from magnesian skarn suggest that the magma source was strongly but

variably degassed during skarn formation while clustering of biotite and tremolite δD data may indicate

ponding of fluids prior to exsolution, which was preceded by monzonite dyke emplacement that were

emplaced during skarn and potassic stage alteration.

Fluid infiltration was controlled by an active fault system characterised by strike-slip deformation

overprinting a pre-existing reverse-slip fault. Periodic slip allowed infiltration of the magmatic fluids

while a complex structural offset controlled the mixing of magmatic and meteoric fluids. Fluid mixing

was augmented by phase separation which gave rise to brine and vapour-rich phases that migrated

differently due to density contrasts. Ore deposition was related to mixing of magmatic and meteoric

fluids, which resulted in an increase in H2S relative to SO2, causing intense sulphidation of magnetite

and precipitation of sulphides, beginning with gold-rich chalcopyrite-dominant mineralization. High

sulphidation covellite-style mineralization occurred by contraction of the vapour phase that had

separated from quartz-forming brines. Au, As and Sb were partitioned away from the high sulphidation

copper mineralization due to higher solubilities of these metals as bisulphide complexes and deposited

in distal pyrite along with chloride-complexed Pb and Zn.

Correction Notes (PhD) – Brian New

Page numbers as they appear here refer to the original review copies rather than the

current edition of the thesis. This was followed as it was thought to be easier for review.

Page numbers have changed through editing making the numbers presented below

obsolete.

Chapter 1 – Introduction (pp1-22)

• Wilkins:

o Sources added for figures 1-1, 1-3 and 1-4.

o Figures 1-5, 1-7, 1-8, 1-9 and 1-10 made larger. Figures 1-8 and 1-9

clarity reduced due to printing hardware quality

• Friehauf:

o Orientation comment added to figure 1-8

o Names of faults added on page12

o Legend of figure 1-9 made larger for better legibility

o Position of Lembah Tembagah described in figure 1-9 caption

o Clear indication of what drill holes logged in this study for figures 1-12

and 1-13

• Richards:

o Sources added/clarified for figures 1-1, 1-3, 1-4, 1-6, 1-7, 1-9

o Details from caption of figure 1-9 added to text on page 13

o Typos page 1, 3, 5, 7

o References page 1 added to list

Chapter 2 – Host Rocks (pp23-46)

• Wilkins:

o Annotations changed in Table 2-1

o Stratigraphic names capitalized as suggested

o Incorrect cross reference page 37

o Included references to plates 2-9 and 2-10

o Removed reference to hornfels on page 44

o Included reference to plate 2-12 in text on page 44

• Friehauf

o Grammar page 24

o Standard abbreviations added to table 2-1

o Clarification page 29

o Hatch symbols explained for figure 2-2

o Limestone-dolostone reference in plate 2-4a

• Richards

o Typo table 2-1

o Clarification figure 2-1

Chapter 3 – Paragenesis (pp47-81)

• Wilkins:

o Grammar page 47

o Missing labels is a computer translation error (*.doc to *.pdf), labels are

present in final version

o Pyrrhotite formula page 66

o Terminology of hornfels-alteration and prograde-retrograde addressed in

section 3-2

o The paragenesis table required by Wilkins is embedded in Chapter 7 as it

did not seem logical to place the conclusions before the evidence. The

paragenetic sequence is an interpretation rather than a fact and the

organization in the thesis reflects this.

• Friehauf

o Grammar and clarification page 47

o Grammar and clarification page 48

o Wrapping figure 3-1

o Grammer page 54

o Grammar and clarification page 61

o Grammar page 67

o Clarification page 69

• Richards

o Missing labels is a computer translation error and are present in final

version

o Grammar page 67

o Grammar page 78

o Clarification page 81

Chapter 4 – Structure (pp82-109)

• Wilkins:

o Caption added for Figure 4-2

o Caption for Figure 4-3, 4-4 and 4-5

o Improved Legend for Figure 4-6

• Friehauf

o Clarification figure 4-1

o Clarification figure 4-6

o Clarification figure 4-9

o Clarification figure 4-10

o Clarification figure 4-11

o Grammar page 108

o Grammar page 109

o Clarification page 109

o References

o Clarification page 110

o

• Richards

o Clarification of authors work page 83

o Spelling Figure 4-3

o Spelling figure 4-8

o Clarification page 109

o Paragraph break page 111

Chapter 5 – Mineralisation (pp110-147)

• Wilkins

o Figure 5-17, 5-22 placement corrected

o Last sentence page 150 removed, speculative and unsupported

• Friehauf

o Grammar page 112, paragraph 1 and 2

o Expanded description page 113 para 3 (middle Waripi sandstone)

o Caption spelling figure 5-3

o Placement figure 5-17

o Placement figure 5-22

o Speculative statement removed page 146 “However, data in this….”

o Spelling caption figure 5-23

o Note on scientific clarity page 149 “cloride-complexed” not chlorine

o Reference Crerar and Barnes, 1976

• Richards

o Figure labels 5-1, cross references in text pp 113-114

o Deformation control sentence page 114

o Grammar paragraph 2 page 114

o Legends figure 5-2, 5-3 and 5-4

o Annotation figure 5-2 to 5-11

o Improved Legend Figure 5-1

o Cross reference page 129 (figure 5-12)

o Comment of tilting of deposit post formation page 129

o Grammar figure 5-13 caption

o Grammar figure 5-14 caption

o Caption order figure 5-18

o Cross reference page 140 (figure 5-21)

o Cross reference figure 5-20 caption (table 5-2)

o Grammar 1st paragraph section 5.2

o Grammar 3rd

paragraph page 145

o Cross reference page 146 (fig 5-13 and 5-14)

o Missing word page 146

o Note on microgeochemical study of sulphides and gold page 146

o Section 5.2 has been reorganized by removing paragraphs concerning

other deposits in district

o Grammar page 149

o Reference to Seward

o From the reading it is deduced that Richards' is actually suggesting a

multivariate analysis be undertaken of element correlations. This is

unnecessary as the element associations referred to are clearly evident in

Figs. 5.5-5.11 and a more quantitative assessment is not required to

support later discussion in the thesis

Chapter 6 – Fluid inclusions (pp148-174)

• Wilkins

o Value changed 650 to 550, section 6.2.1

• Friehauf

o Grammar tense, second sentence page 151

o Clarification mineral species figure 6-3 and 6-4

o Second image added to figure 6-6, inclusions represented by fluid

inclusion type

• Richards

o Section headings altered to properly define content

o Issue of format translation (.doc to .pdf) for missing labels, labels are

present in final version

o Classification of inclusions, plate 6-4, 6-5 and 6-6

o Clarity page 162 “some deeper ….”

o Page 163, clarify SLV inclusions form high relief phases

o Figure 6-2, note on bin ranges added to caption

o Figure 6-3, note on bin ranges added to caption

o Ice melting by inclusion type graph added to figure 6-4

o Salt melting graph made to individual figure 6-5

o Notes on high temperatures page 168.

o Sentence removed p169 “All the high…..”

o Grammar page 169 (comma inserted)

o Alterations to opening statements section 6.2

o Section 6.2.1 final statements removed

o Paragraph on fluid inclusions on page 173 merged with paragenesis

section, as to whether inclusions are primary, pseudosecondary or

secondary

o Rewrite of final section to consider models of fluid development from

magma depth of emplacement, fluid separation and different magma

sources

o The fluid inclusions presented in the chapter have been reevaluated in

terms of primary, secondary and pseudosecondary where possible and a

note has been added that was not always possible to definitively assign a

timing criteria to each. In addition, the definitive statements that a boiling

assemblage is supported by the evidence is removed and reappraised to

indicate that the observed inclusions plus homogenization temperature

data may support a boiling assemblage and that the weight of evidence

points to a boiling assemblage.

o In his skepticism of the high temperatures assumed for quartz deposition

Richards has ignored previous data in foundation papers (Wilkins, 1974)

on fluid inclusion studies that indicated temperatures of formation >700°C

as well as data collected locally at Grasberg from another researcher

(Harrison, 2000).

o Standard phase change symbols have been used throughout the thesis and

where they are impractical an explanation has been added to the figure

caption. For examples, where all fluid inclusion data are presented in a

graph relating to sample number it is not possible to identify which

inclusions have homogenized vapour to liquid, liquid to vapour, or to salt.

In these instances the symbol ThFINAL has been used.

Chapter 7 – Stable Isotopes (pp175-193)

• Wilkins

o Figure 7-1 and 7-3, missing labels due to *.doc to *.pdf translation

o Figure 7-2 increased in size to fill 2 pages

• Friehauf

o Clarified who did anlyses on opening page Chapter 7

o Grammar section 7.1 page 176

o Legend figure 7-1 problem with format translation

• Richards

o Analytical people specified opening page chapter 7

o Calcite instead of limestone opening page chapter 7

o Grammar paragraph 1 section 7.1.1

o Clarification of anhydrite values (del18O) page 177 para 3 section 7.1.1

o Temperature justification figure 7-2 added end of paragraph 2 section

7.1.2

o Correction “due to preferential fractionation….” Section 7.2 opening

paragraph. Sentence removed

o Grammar paragraph 1 section 7.2

o Incorrect reference (Campbell and Larson, 1998) paragraph 2 section 7.2

o Note of high water-rock ratio added to sentence 3 paragraph 3 section 7.2

o Possibility of mixing added paragraph 3 section 7.2

o Figure 7-4 and 7-5 labelling

o Note “at high temperature” added to sentence 3 on section titled

“magmatic exsolution processes”

o The suggestion by Richards for reorganization of the chapter along lines

of isotope rather than data and analysis seems to be a matter of personal

preference as the other two examiners were quite happy with approach

taken

o Assessment of possible errors in fractionation is present in the thesis as

graphs of fractionation curves showing the position of the assumed

temperature. From these graphs it is possible to guage the difference if a

temperature of ±50, 100 or 150 degrees is assumed.

Chapter 8 – Geochronology (pp194-212)

• Wilkins

o References for Mathur et al. (2000) and Mathur et al. (2005)

• Friehauf

o Details of analytical personnel opening page Chapter 8

o Note on word choice page 208 (indicates replaced by suggests)

• Richards

o Repetition third sentence opening page removed

o Analytical person clearly stated opening page chapter 8

o Word choice page 194 (constituted replaced by consisted)

o Figure labels page 197 file format translation (*.doc to *.pdf)

o Grammar, section 8.1.2 (now 8.2) paragraph 1

o Correction of age dates, section 8.1.2 (now 8.2) paragraph 2

o Grammar, section 8.1.2 (now 8.2) paragraph 2

o Discussion of age graphs copied from appendix to figure captions

o Increased data on table 8-1 to include plateau and isochron ages

o

o Removed last sentence section 8.2 paragraph 2 to opening page chapter 8

o Cross reference to figure 8-11 changed to table 8-3 in 1st paragraph

“geochronology of the ertsberg mining district”

o Grammar page 209

Chapter 9 – Discussion

• Wilkins

o 1st note means as in text

o Figure labels and cross references for figure 9-2, 9-3, 9-4 and 9-5

o Figure 9-5 label

o Cross reference figure 9-8 in 1st sentence-paragraph of section 9.3.2

• Richards

o Grammar opening page Chapter 9

o Grammar 1st paragraph section 9.1

o Figure 9-1 caption reference and description of figure

o Labels on Figure 4-5

o Rearrangement paragraph 3 section 9.2.2 “the origin of….”

o Reorder figure 9-6 and 9-7 to reflect sequence of cross references

o Clarity paragraph 3 section 9.3.1 (economic interest and fO2)

o Reference and spelling Figure 9-6 (now figure 9-7)

o Reference Figure 9-7 (now figure 9-6)

o 2nd

paragraph section 9.1.2, “Fluid flow….probably produced”, “fluid

infiltration most likely occurred”

o 1st paragraph 9.2.1, “Quartz alteration also…..probably not related….and

could be interpreted…”

o 2nd

paragraph 9.2.1 “Quartz alteration is closely….and this association

may indicate…”

o 2nd

paragraph 9.2.1 “Fluid dilution…may also have….”

o 2nd

paragraph 9.2.1 “However, If phase separation of hydrothermal fluids

did occur at Kucing Liar…”

o 1st paragraph 9.2.2 “Higher degrees of local water…..” is now “A higher

degree of local water interaction is believed to have promoted….”

o 1st paragraph 9.2.2 “The effect of reduced temperatures in the system was

probably…”

o 3rd

paragraph 9.2.2 ” Low salinity magmatic fluids related to covellite

mineralization were circulating at temperatures…”

o 3rd

paragraph 9.2.2 “Phase separation appears to have been was probably

limited…”

o Discussion and Conclusions have been rewritten taking into account

uncertainties and changed interpretations as required by Richards. In many

instances this relates to the interpretation of the fluid inclusion assemblage

where Richards believes that not enough information has been collected to

support a boiling assemblage. Discussion with others at JCU and perusal

of existing literature suggests that there is a weight of evidence that

supports a boiling assemblage, however, the thesis has been revised to

reflect the opinion of Richards.