steve garwin
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Tectonic and Structural Controls to Porphyry and Epithermal Mineralization in CenozoicMagmatic Arcs of SE Asia and the W Pacific
STEVE GARWINIndependent Consultant
sgar@iinet.net.au 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
(Garwin et al., 2005)
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
> 5 M Oz Au Resource>10 M Oz Au Resource
Indonesian Region – Tectonic Elements
> 5 M Oz Au Resource>10 M Oz Au Resource
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)
> 5 M Oz Au Resource>10 M Oz Au Resource
Indonesian Region – Gold and Copper Deposits
> 5 M Oz Au Resource>10 M Oz Au Resource
Martabe
Indonesian Region – Gold and Copper Deposits
> 5 M Oz Au Resource>10 M Oz Au Resource
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
(Garwin et al., 2005)
>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
> 5 M Oz Au Resource>10 M Oz Au Resource
(Garwin et al., 2005)
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 sgar@iinet.net.au
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.
REFERENCES sgar@iinet.net.au
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.
REFERENCES sgar@iinet.net.au
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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