Steve Garwin

Tectonic and Structural Controls to Porphyry and Epithermal Mineralization in CenozoicMagmatic Arcs of SE Asia and the W Pacific

STEVE GARWINIndependent Consultant

[email protected] Grasberg, 24 Mt Cu / 2560 t Au

AIG Annual Meeting – Keynote Lecture27th May, 2013 Sanur - Bali, Indonesia

Cenozoic Magmatic Arcs and Au-(Cu) Deposits of SE Asia and W Pacific

> 5 M Oz Au Resource>10 M Oz Au Resource

(Garwin et al., 2005)

Gold and Copper Contents (%, metric tonnes)of Deposit Styles in SE Asia & W Pacific

Au

Cu


15

3

2

62

28 Deposits > 5 M Oz Au

GOLD AND COPPER - GOLD DEPOSITSGOLD AND COPPER - GOLD DEPOSITSSOUTHEAST ASIASOUTHEAST ASIA

Aver

age

Gol

d G

rade

(g/t

Au)

Deposit Size (million tonnes)

Low- and intermediate-sulfidation classifications for data in this plot were made by Garwin in 2002; the classifications were revised

by Garwin et al. (2005).

Porphyry and Epithermal DepositsControls to Mineralization: SE Asia – W Pacific

• Neogene to Pleistocene magmatic activity

• Subduction slab discontinuity (e.g., kinks / tears)

• Fault inversion along collisional margin (New Guinea)

• Arc-transverse fault zone(s) that control magmatism

& sedimentation – structural link to the mantle

• Region of contraction / uplift / exhumation

• Structural settings favorable to focus heat-

and fluid-flow (e.g., stress-transition regime)

SE Asia Tectonic Elements, Cenozoic Magmatic Arcs and Large Porphyry and Epithermal Deposits Shown on Sea-floor Bathymetry and DEM

105°00’E

0°00’ 0°00’

10°00’S 10°00’S

105°00’E

DEM USGS EROS Data Centre250 meter resolution

Bathymet ry NOAA-AVHRR Sandwell database1000 meter resolution

115°00’E

115°00’E

125°00’E

125°00’E

135°00’E

135°00’E

K M

0 400 8002000m1000m200m50m0m

0m200m3000m

Elevation Bathymetry

Digital Elevation Model and Bathymetry of Indonesia

Roo Rise

Inve

stig

ator

Rid

ge

Indonesian Region – Tectonic Elements


Indonesian Region – Tectonic Elements


Interpretation of tectonic elements for the Indonesian region, after Garwin et al. (2005). Tectonic elements and lineaments are interpreted from digital topography models, satellite gravity and bathymetry, and Radarsat (ERS) data described by Garwin (2000), and reflect compilation and modification of the results of Hamilton (1979), McCaffrey (1988 and 1996), Hutchison (1989), Garwin (1996), Hall (1996), Simandjuntuk and Barber (1996), and Snyder et al. (1996). The magmatic arcs and orogenic belts are modified from Hamilton (1979), Hutchison (1989), Carlile and Mitchell (1994), and Garwin (1996, 2000).

Indonesian Region – Earthquake Hypocenters (1973-2010)

Mw > 4.0 (hypocenters above depth of 25 km are not shown)


Indonesian Region – Gold and Copper Deposits


Martabe

Indonesian Region – Gold and Copper Deposits


Martabe

Major gold and copper districts, deposits and prospects of the Indonesian region (after Garwin, 2000). The magmatic arcs and orogenic belts are modified from Hamilton (1979), Hutchison (1989), Carlile and Mitchell (1994) and Garwin (1996). The tectonic features and lineaments are interpreted from the digital elevation model, AVHRR, satellite gravity, bathymetry and Radarsat (ERS) databases and reflect the results of previous authors, such as Hamilton (1979), McCaffrey (1988, 1996), Hutchison (1989), Pulunggono (1993), Garwin (1996), Hall (1996), Simandjuntuk and Barber (1996) and Snyder et al. (1996).

INDONESIAN REGION TECTONIC ELEMENTS & PORPHYRY DEPOSITS

INDONESIAN REGION TECTONIC ELEMENTS & PORPHYRY DEPOSITS

30o

40o

60o>70o

EQ<300km EQ

>600km

Toba

Krakatoa

Martabe

T. Bukit

RooRise

55o

65o

500 km

(Modified from McCaffrey, 1988)

2 - 3 mm/yr E-W extension on strike-slip faults.

Hypocenter depths < 30 km

N15oE subduction at 7 cm/yr.

EAST SUNDA & BANDA ARCS, INDONESIAEARTHQUAKE FAULT PLANE SOLUTIONS

Batu Hijau

Elang

T Bukit

East Sunda ArcMetal Deposits, Geology, DEM / Bathymetry

(Maryono and Setijadji, 2012)

Roo Rise

Simplified Geology of SumbawaDifferential Exhumation

Elang

Hu’ u

Soripesa

Most uplifted

Western block

Central block

Eastern blockLeast uplifted

Amphibole

Crustal-scale arc-transverse fault system occurs in the arc above a kink, or tear, in the subducting slab

Rapid rise of asthenospheric melts and efficient release of mineralizing fluids at high crustal-levels

INTRUSION-RELATED MINERALIZATION & TECTONICS

Uplift

Tectonic Framework of Luzon, Philippines

100 km

Scarborough Seamounts


>10 M Oz Au Resource

30o

70o

60o

Uplift from ~ 4 Ma

Sea-floor Bathymetry of Luzon, Philippines

Lepanto - FSE

BaguioSto. Thomas

Scarborough Seamounts

Stuart Bank

Vigan High

Papua New Guinea and Papua, IndonesiaAu – (Cu) Deposits and Settings



Golpu

(Gow and Walshe, 2005)

Papua New Guinea Basement Faults and Cross-Sructures

>10 M Oz Au Resource

Neogene Thrust Inversion of Mesozoic Extensional Faults in Cratonic Basement – Porgera Example (6-5 Ma)

(Hill et al., 2002)

Geodynamic Model for Structural Setting to Pliocene Cu-Au Deposits in Papuan Fold Belt of New Guinea

(Hill et al., 2002)

EXHUMATION RATES - OROGENIC REGIONSEXHUMATION RATES - OROGENIC REGIONS

Alps, Italy

Batu Hijau

Alpine Fault, NZ

Grasberg

Atauro IslandKupang

Semau Island

Boso, Japan

Roti Island

Alpine Fault, NZ

Exhu

mat

ion

Rat

e (m

m/ y

r)

Duration (mybp to present)

West Solomon Is: 8 mm/yr (50 K yrs)Alpine Fault, NZ:7-8 mm/yr (14 K yrs)Longitudinal Valley Fault, E. Taiwan:23 mm/yr (8 yrs - now)

Porphyry and Epithermal DepositsFavorable Geological – Structural Settings: SE Asia

• Dilational zones in long-lived fault systems

• Basement high / dome / anticline / horst-block

• Batholith / horst margins in zones of low mean-stress

• Dike swarms as paleo-stress indicators

-orientation, composition and age

• Thin, young cover sequences in arc-transverse belts

- volc-sed basins, alt magmatic centers, po intrusions

• Mineralized rock fragments in cover sequences

Volcano-sedimentary Rocks

Intrusions

AlluviumQuaternary

Plio-Pleistocene

Early PlioceneLate Miocene-

Late Miocene

Mid- Pliocene

Early toMiddle Miocene

Volcaniclastic rocksAndesitic domes and dykes

Andesitic volcaniclastics

Limestones

Coral reef

Dacitic volcaniclastic

DiatremeTonalite porphyry

Quartz diorite

Porphyritic tonalite

Undifferentiated quartz diorite

Phyric andesite

Volcanic conglomerate

Volcanic lithic brecciaLimestoneVolcanic sandstoneUndiff volcanics volcaniclastics

EXPLANATION

480 000E 500 000E117°00'E

9°00'S

9 020 000N

I N D I A N O C E A N

A L

A S

S

T R A

I T

BATU HIJAU

N

5 kilometers

A

B

SymbolsQuartz vein zoneFault

Topographic lineament

Batu Hijau ultimate pit

Bedding25

Simplified Geology – Batu Hijau, SW Sumbawa

A B

-2

4 KM

-2

-1-1

0 km0 km

11

22 d citia c volcaniclastic sequence

Schematic Cross Section - SW Sumbawa

AlluviumVolcaniclastic rocksLimestoneDacitic volcaniclasticsVolcanic lithic brecciaLimestoneVolcanic sandstone

Volcano-sedimentary RocksQuaternary

Plio-Pleistocence

Late Miocence to Early Pliocene

Early to Middle Miocene

Tonalite porphyryPorphyritic tonaliteEg quartz dioritePhyric andesite

Fault

IntrusionsMid-Pliocene

Late Miocene

N20oW S20oE

Batu Hijau District Geophysical Signature -Airborne Magnetics

NAGA EMAS

500 m

Hishikari, Southern Kyushu5.5 MT @ 55 g/t Au (1996)

Izawa et al., 1990

Il-SmQz-Sm

Cr-Sm

Andesitic PyroclasticsDacite

Andesite

NW SERegional Section

Mine Section

HishikariCross-Section B-B’

Izawa et al., 1990

Il-Sm

Qz-SmCr-Sm Dacite

Andesite

Ch-Se

Basement Siliciclastic Rocks

NW SE

Gravity High

Hishikari Honko vein system Greywacke

basementHigh > 100 g/t AuMedium / Low =

“confidential”

Porphyry and Epithermal DepositsControls to Mineralization: SE Asia – W Pacific

• Neogene to Pleistocene magmatic activity

• Subduction slab discontinuity (e.g., kinks / tears)

• Fault inversion along collisional margin (New Guinea)

• Arc-transverse fault zone(s) that control magmatism

& sedimentation – structural link to the mantle

• Region of contraction / uplift / exhumation

• Structural settings favorable to focus heat-

and fluid-flow (e.g., stress-transition regime)

BATU HIJAU MINE 2011

Looking southwest

REFERENCES [email protected]

Carlile, J. C., and Mitchell, A. H. G., 1994, Magmatic arcs and associated gold and copper mineralization in Indonesia, in van Leeuwen T. M., Hedenquist, J. W., James, L. P., and Dow, J. A. S., eds., Mineral deposits of Indonesia; discoveries of the past 25 years., Journal of Geochemical Exploration v. 50; 1-3, p. 91-142.Cooke, D.R, Heithersay, P.S., Wolfe, R., and Calderon, A.L., 1998, Australian and western Pacific porphyry Cu-Au deposits, AGSO Journal of Australian Geology & Geophysics, 17(4), pp. 97-104.Corbett, G.J., and Leach, T.M., 1998, Southwest Pacific Rim gold-copper systems: Structure, alteration and mineralization, Society of Economic Geologists Special Publication 6, 240 p.Garwin, S.L., 2000, The setting, geometry and timing of intrusion-related hydrothermal systems in the vicinity of the Batu Hijau porphyry copper-gold deposit, Sumbawa, Indonesia: Unpublished Ph.D. thesis, University of Western Australia, Nedlands, Western Australia, Australia, 320 p. (plus figures and appendices).Garwin, S., 2002, The geologic setting of intrusion-related hydrothermal systems near the Batu Hijau porphyry copper-gold deposit, Sumbawa, Indonesia, in Goldfarb, R.J. and Nielsen, R.L. eds., Integrated Methods for Discovery: Global Exploration in the 21st Century, Society of Economic Geologists, Special Publication 9, p. 333-366.Garwin, S., Hall, R., and Watanabe, Y., 2005. Tectonic setting, geology and gold and copper mineralization in Cenozoic magmatic arcs of Southeast Asia and the west Pacific, in Hedenquist, J., Goldfarb, R. and Thompson, J. (eds.), Economic Geology 100th Anniversary Volume, Society of Economic Geologists, p. 891-930.Gow, P.A., and Walshe, J.L., 2005. The role of pre-existing geologic architecture in the formation of giant porphyry-related Cu + Au deposits: examples from New Guinea and Chile, Economic Geology, Society of Economic Geologistsv. 100, pp. 819-833.


Hall, R., 2002, Cenozoic geological and plate tectonic evolution of SE Asia and the SW Pacific: computer-based reconstructions, model and animations: Journal of Asian Earth Sciences, v. 20, p. 353-434.Hamilton, W., 1979, Tectonics of the Indonesian region: U.S. Geological Survey Professional Paper, v. 1078, p. 345 p.Hill, K. C., Kendrick, R. D., Crowhurst, P. V., and Gow, P. A., 2002, Copper-gold mineralisation in New Guinea; tectonics, lineaments, thermochronology and structure, in Korsch, R. J., ed., Geodynamics of Australia and its mineral systems; technologies, syntheses and regional studies, Blackwell Scientific Publications for the Geological Society of Australia. Melbourne, Australia, p. 737-752.Hutchison, C.S., 1989, Geological Evolution of Southeast Asia, Oxford Monographs on Geology and Geophysics, 13, Carendon Press, Oxford, United Kingdom, 368 p.Kerrich, R., Goldfarb, R. J., Groves, D. I., and Garwin, S., 2000, The geodynamics of world-class gold deposits; characteristics, space-time distribution, and origins, in Hagemann S.G., and Brown, P.E., eds., Reviews in Economic Geology, v. 13, p. 501-551.Mitchell, A. H. G., and Leach, T. M., 1991, Epithermal gold in the Philippines; island arc metallogenesis, geothermal systems and geology, Academic Press, London, United Kingdom, 457 p.Seedorff, E., Dilles, J.H., Proffett, J.M., Einauidi, M.T., Zurcher, L., Stavast, W.J.A., Johnson, D.A., and Barton, M.D., Porphyry deposits: Characteristics and origin of hypogene features, in Hedenquist, J., Goldfarb, R. and Thompson, J. (eds.), Economic Geology 100th Anniversary Volume, Society of Economic Geologists, p. 251-298.Sillitoe, R.H., and Gappe, I.M., Jr., 1984, Philippine porphyry copper deposits; geologic setting and characteristics: UNDP Technical Support for Regional Offshore Prospecting in East Asia; United Nations, Economic and Social Commission for Asia and the Pacific, 89 p.


Sillitoe, R.H., and Hedenquist, J. W., 2003, Linkages between volcanotectonic settings, ore-fluid compositions, and epithermal precious-metal deposits, in Simmons, S. F., and Graham, I., eds., Giggenbach Volume, Special Publication 10, Society of Economic Geologists and Geochemical Society, p. 315-343.Sillitoe, R.H., and Perello, J., 2005, Andean copper province: Tectonmagmatic settings, deposit types, metallogeny, exploration and discovery, in Hedenquist, J., Goldfarb, R. and Thompson, J. (eds.), Economic Geology 100th Anniversary Volume, Society of Economic Geologists, p. 845-890.Tosdal, R.M., and Richards, J.P., 2001, Magmatic and structural controls on the development of porphyry Cu ± Mo ± Au deposits: Reviews in Economic Geology, v. 14, p. 157-181.van Bemmelen, R.S., 1949, The Geology of Indonesia, v. II, Economic Geology, Government Printing Office, The Hague, Netherlands, 265 p.Yang, T. F., Lee, T., Chen, C. H., Cheng, S. N., Knittel, U., Punongbayan, R. S., and Rasdas, A. R., 1996, A double island arc between Taiwan and Luzon; consequence of ridge subduction: Tectonophysics, v. 258, p. 85-101.

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