pacrim 2015, hong kong the mesozoic iocg deposits in the ... · the mesozoic iocg deposits in the...
TRANSCRIPT
![Page 1: PACRIM 2015, Hong Kong The Mesozoic IOCG Deposits in the ... · The Mesozoic IOCG Deposits in the Central Andes A Refined IOCG Ore-forming Model ... (Pollard, 2001, 2006; Marschik](https://reader036.vdocuments.net/reader036/viewer/2022062600/5ac6852a7f8b9a333d8e7dcf/html5/thumbnails/1.jpg)
The Mesozoic IOCG Deposits in the Central Andes
A Refined IOCG Ore-forming Model in the
Palaeozoic Continental Margin
Huayong Chen
Guangzhou Institute of Geochemistry Chinese Academy of Sciences
PACRIM 2015, Hong Kong
![Page 2: PACRIM 2015, Hong Kong The Mesozoic IOCG Deposits in the ... · The Mesozoic IOCG Deposits in the Central Andes A Refined IOCG Ore-forming Model ... (Pollard, 2001, 2006; Marschik](https://reader036.vdocuments.net/reader036/viewer/2022062600/5ac6852a7f8b9a333d8e7dcf/html5/thumbnails/2.jpg)
Distribution of IOCG Deposits
Modified from Corriveau, 2007
Cloncurry
Olympic Dam
Norbotten
Central Andes Carajás
Kangdian
![Page 3: PACRIM 2015, Hong Kong The Mesozoic IOCG Deposits in the ... · The Mesozoic IOCG Deposits in the Central Andes A Refined IOCG Ore-forming Model ... (Pollard, 2001, 2006; Marschik](https://reader036.vdocuments.net/reader036/viewer/2022062600/5ac6852a7f8b9a333d8e7dcf/html5/thumbnails/3.jpg)
Global Resources of IOCG Deposits Deposit Tonnage
(Mt) Cu (%)
Au (g/t)
Ag (g/t)
Other metals (%)
Olympic Dam, Australia
3810 1.0 0.5 3.6 U (0.04) REE
Salobo, Brazil 789 0.96 0.52 55
Cristalino, Brazil 500 1.0 0.3
Aitik, Sweden 606 0.38 0.21
Candelaria, Chile 470 0.95 0.22 3.1
Mantoverde, Chile 400 0.52 0.11
Mina Justa, Peru 347 0.71 0.03 3.83
Ernest Henry, Australia
167 1.1 0.54 Co (0.05)
![Page 4: PACRIM 2015, Hong Kong The Mesozoic IOCG Deposits in the ... · The Mesozoic IOCG Deposits in the Central Andes A Refined IOCG Ore-forming Model ... (Pollard, 2001, 2006; Marschik](https://reader036.vdocuments.net/reader036/viewer/2022062600/5ac6852a7f8b9a333d8e7dcf/html5/thumbnails/4.jpg)
Timing of IOCG
Deposits
Corriveau, 2009
Late Archean Carajas District, Brazil
Early-mid Proterozoic Olympic Dam, Cloncurry District, Australia; Aitik, Sweden Kangdian district, China
Mesozoic Central Andes
![Page 5: PACRIM 2015, Hong Kong The Mesozoic IOCG Deposits in the ... · The Mesozoic IOCG Deposits in the Central Andes A Refined IOCG Ore-forming Model ... (Pollard, 2001, 2006; Marschik](https://reader036.vdocuments.net/reader036/viewer/2022062600/5ac6852a7f8b9a333d8e7dcf/html5/thumbnails/5.jpg)
IOCG Model: Ore-forming fluids
Williams et al., 2005; Williams, 2009
![Page 6: PACRIM 2015, Hong Kong The Mesozoic IOCG Deposits in the ... · The Mesozoic IOCG Deposits in the Central Andes A Refined IOCG Ore-forming Model ... (Pollard, 2001, 2006; Marschik](https://reader036.vdocuments.net/reader036/viewer/2022062600/5ac6852a7f8b9a333d8e7dcf/html5/thumbnails/6.jpg)
IOCG Ore-forming fluids Debate in the Central Andes
IO + CG
Magmatic-hydrothermal (Pollard, 2001, 2006; Marschik and Fontboté, 2001; Sillitoe, 2003; Rieger et al., 2010)
Similar to Porphyry, Skarn systems
Non-magmatic hydrothermal (Ullrich and Clark, 1999; Benavides et al., 2007; Chen
et al., 2011; Marschik and Kendrick, 2014)
![Page 7: PACRIM 2015, Hong Kong The Mesozoic IOCG Deposits in the ... · The Mesozoic IOCG Deposits in the Central Andes A Refined IOCG Ore-forming Model ... (Pollard, 2001, 2006; Marschik](https://reader036.vdocuments.net/reader036/viewer/2022062600/5ac6852a7f8b9a333d8e7dcf/html5/thumbnails/7.jpg)
IOCG’s in the Andes
Mina Justa ([email protected]% Cu 3.8g/t Ag; 0.03g/t Au)
Mantoverde ([email protected]% Cu 0.11g/t Au)
La Candelaria ([email protected]% Cu 0.22g/t Au)
![Page 8: PACRIM 2015, Hong Kong The Mesozoic IOCG Deposits in the ... · The Mesozoic IOCG Deposits in the Central Andes A Refined IOCG Ore-forming Model ... (Pollard, 2001, 2006; Marschik](https://reader036.vdocuments.net/reader036/viewer/2022062600/5ac6852a7f8b9a333d8e7dcf/html5/thumbnails/8.jpg)
To constrain a ore deposit model
Candelaria, Chile
1. Ore Deposit Geology
2. Paragenesis of alteration and mineralization
3. Nature of ore-forming fluids
Ore Deposit Model
![Page 9: PACRIM 2015, Hong Kong The Mesozoic IOCG Deposits in the ... · The Mesozoic IOCG Deposits in the Central Andes A Refined IOCG Ore-forming Model ... (Pollard, 2001, 2006; Marschik](https://reader036.vdocuments.net/reader036/viewer/2022062600/5ac6852a7f8b9a333d8e7dcf/html5/thumbnails/9.jpg)
Regional Geology of South-Central Peru
Chen et al., 2010
![Page 10: PACRIM 2015, Hong Kong The Mesozoic IOCG Deposits in the ... · The Mesozoic IOCG Deposits in the Central Andes A Refined IOCG Ore-forming Model ... (Pollard, 2001, 2006; Marschik](https://reader036.vdocuments.net/reader036/viewer/2022062600/5ac6852a7f8b9a333d8e7dcf/html5/thumbnails/10.jpg)
Deposit Geology – Mina Justa
![Page 11: PACRIM 2015, Hong Kong The Mesozoic IOCG Deposits in the ... · The Mesozoic IOCG Deposits in the Central Andes A Refined IOCG Ore-forming Model ... (Pollard, 2001, 2006; Marschik](https://reader036.vdocuments.net/reader036/viewer/2022062600/5ac6852a7f8b9a333d8e7dcf/html5/thumbnails/11.jpg)
Deposit Geology – Mina Justa
Chen et al., 2010
![Page 12: PACRIM 2015, Hong Kong The Mesozoic IOCG Deposits in the ... · The Mesozoic IOCG Deposits in the Central Andes A Refined IOCG Ore-forming Model ... (Pollard, 2001, 2006; Marschik](https://reader036.vdocuments.net/reader036/viewer/2022062600/5ac6852a7f8b9a333d8e7dcf/html5/thumbnails/12.jpg)
Location of the Chilean IOCGs
![Page 13: PACRIM 2015, Hong Kong The Mesozoic IOCG Deposits in the ... · The Mesozoic IOCG Deposits in the Central Andes A Refined IOCG Ore-forming Model ... (Pollard, 2001, 2006; Marschik](https://reader036.vdocuments.net/reader036/viewer/2022062600/5ac6852a7f8b9a333d8e7dcf/html5/thumbnails/13.jpg)
Ages of host rocks in the Mantoverde district: Sierra Dieciocho pluton 120-125 Ma La Negra Formation: Middle to Upper Jurassic
Deposit Geology of
Mantoverde
Benavides et al., 2007
![Page 14: PACRIM 2015, Hong Kong The Mesozoic IOCG Deposits in the ... · The Mesozoic IOCG Deposits in the Central Andes A Refined IOCG Ore-forming Model ... (Pollard, 2001, 2006; Marschik](https://reader036.vdocuments.net/reader036/viewer/2022062600/5ac6852a7f8b9a333d8e7dcf/html5/thumbnails/14.jpg)
Benavides et al., 2007
Cu orebody
magnetite
![Page 15: PACRIM 2015, Hong Kong The Mesozoic IOCG Deposits in the ... · The Mesozoic IOCG Deposits in the Central Andes A Refined IOCG Ore-forming Model ... (Pollard, 2001, 2006; Marschik](https://reader036.vdocuments.net/reader036/viewer/2022062600/5ac6852a7f8b9a333d8e7dcf/html5/thumbnails/15.jpg)
Deposit Geology – La Candelaria
After Marschik and Fontboté, 2001
![Page 16: PACRIM 2015, Hong Kong The Mesozoic IOCG Deposits in the ... · The Mesozoic IOCG Deposits in the Central Andes A Refined IOCG Ore-forming Model ... (Pollard, 2001, 2006; Marschik](https://reader036.vdocuments.net/reader036/viewer/2022062600/5ac6852a7f8b9a333d8e7dcf/html5/thumbnails/16.jpg)
La Candelaria Cross section
Modified from Marschik and Fontboté, 2001; Arevalo et al., 2006
![Page 17: PACRIM 2015, Hong Kong The Mesozoic IOCG Deposits in the ... · The Mesozoic IOCG Deposits in the Central Andes A Refined IOCG Ore-forming Model ... (Pollard, 2001, 2006; Marschik](https://reader036.vdocuments.net/reader036/viewer/2022062600/5ac6852a7f8b9a333d8e7dcf/html5/thumbnails/17.jpg)
Summary of Geology
1. located in the margin of the Mesozoic volcanic basin
2. controlled by faults (most are normal or detachement)
3. genetic relationships to intrusions not clear in many cases
Coast near Mantoverde Chile
![Page 18: PACRIM 2015, Hong Kong The Mesozoic IOCG Deposits in the ... · The Mesozoic IOCG Deposits in the Central Andes A Refined IOCG Ore-forming Model ... (Pollard, 2001, 2006; Marschik](https://reader036.vdocuments.net/reader036/viewer/2022062600/5ac6852a7f8b9a333d8e7dcf/html5/thumbnails/18.jpg)
To constrain a ore deposit model
Candelaria, Chile
1. Ore Deposit Geology
2. Paragenesis of alteration and mineralization
3. Nature of ore-forming fluids
Ore Deposit Model
![Page 19: PACRIM 2015, Hong Kong The Mesozoic IOCG Deposits in the ... · The Mesozoic IOCG Deposits in the Central Andes A Refined IOCG Ore-forming Model ... (Pollard, 2001, 2006; Marschik](https://reader036.vdocuments.net/reader036/viewer/2022062600/5ac6852a7f8b9a333d8e7dcf/html5/thumbnails/19.jpg)
Alteration and Mineralization Paragenesis– Mina Justa
![Page 20: PACRIM 2015, Hong Kong The Mesozoic IOCG Deposits in the ... · The Mesozoic IOCG Deposits in the Central Andes A Refined IOCG Ore-forming Model ... (Pollard, 2001, 2006; Marschik](https://reader036.vdocuments.net/reader036/viewer/2022062600/5ac6852a7f8b9a333d8e7dcf/html5/thumbnails/20.jpg)
Alteration and Mineralization Paragenesis– Mina Justa
![Page 21: PACRIM 2015, Hong Kong The Mesozoic IOCG Deposits in the ... · The Mesozoic IOCG Deposits in the Central Andes A Refined IOCG Ore-forming Model ... (Pollard, 2001, 2006; Marschik](https://reader036.vdocuments.net/reader036/viewer/2022062600/5ac6852a7f8b9a333d8e7dcf/html5/thumbnails/21.jpg)
Alteration and Mineralization Paragenesis– Mina Justa
540- 600 oC
80-220 oC (mode at 140 oC)
154-156 Ma 142 Ma
109 Ma
101-104 Ma
95-99 Ma
![Page 22: PACRIM 2015, Hong Kong The Mesozoic IOCG Deposits in the ... · The Mesozoic IOCG Deposits in the Central Andes A Refined IOCG Ore-forming Model ... (Pollard, 2001, 2006; Marschik](https://reader036.vdocuments.net/reader036/viewer/2022062600/5ac6852a7f8b9a333d8e7dcf/html5/thumbnails/22.jpg)
Alteration and Mineralization – Mantoverde
128 Ma (U-Pb)
117-121 Ma (K-Ar)
Benavides et al., 2007
![Page 23: PACRIM 2015, Hong Kong The Mesozoic IOCG Deposits in the ... · The Mesozoic IOCG Deposits in the Central Andes A Refined IOCG Ore-forming Model ... (Pollard, 2001, 2006; Marschik](https://reader036.vdocuments.net/reader036/viewer/2022062600/5ac6852a7f8b9a333d8e7dcf/html5/thumbnails/23.jpg)
Alteration and Mineralization – La Candelaria
(Ullrich and Clark, 1999)
115 Ma
112 Ma
Act Cpy Mus
Mt
![Page 24: PACRIM 2015, Hong Kong The Mesozoic IOCG Deposits in the ... · The Mesozoic IOCG Deposits in the Central Andes A Refined IOCG Ore-forming Model ... (Pollard, 2001, 2006; Marschik](https://reader036.vdocuments.net/reader036/viewer/2022062600/5ac6852a7f8b9a333d8e7dcf/html5/thumbnails/24.jpg)
Summary of Paragenesis
Candelaria, Chile
1. magnetite stage commonly prior to the Cu stage, could be about 5-10 my. in some cases
2. magnetite stage could form under much higher temperatures than Cu stage
3. Calcite and hematite are common in Cu stage
![Page 25: PACRIM 2015, Hong Kong The Mesozoic IOCG Deposits in the ... · The Mesozoic IOCG Deposits in the Central Andes A Refined IOCG Ore-forming Model ... (Pollard, 2001, 2006; Marschik](https://reader036.vdocuments.net/reader036/viewer/2022062600/5ac6852a7f8b9a333d8e7dcf/html5/thumbnails/25.jpg)
To constrain a ore deposit model
Candelaria, Chile
1. Ore Deposit Geology
2. Paragenesis of alteration and mineralization
3. Nature of ore-forming fluids
Ore Deposit Model
![Page 26: PACRIM 2015, Hong Kong The Mesozoic IOCG Deposits in the ... · The Mesozoic IOCG Deposits in the Central Andes A Refined IOCG Ore-forming Model ... (Pollard, 2001, 2006; Marschik](https://reader036.vdocuments.net/reader036/viewer/2022062600/5ac6852a7f8b9a333d8e7dcf/html5/thumbnails/26.jpg)
Low-temperature fluids of the Cu mineralization stage, Mina Justa
• Low-T, Ca-dominant medium to high salinity (basin brine ?) • Low-T, Na-K dominant low salinity (meteoric water ?)
![Page 27: PACRIM 2015, Hong Kong The Mesozoic IOCG Deposits in the ... · The Mesozoic IOCG Deposits in the Central Andes A Refined IOCG Ore-forming Model ... (Pollard, 2001, 2006; Marschik](https://reader036.vdocuments.net/reader036/viewer/2022062600/5ac6852a7f8b9a333d8e7dcf/html5/thumbnails/27.jpg)
Laser Ablation-Time Of Flight-ICPMS analysis of individual inclusions
![Page 28: PACRIM 2015, Hong Kong The Mesozoic IOCG Deposits in the ... · The Mesozoic IOCG Deposits in the Central Andes A Refined IOCG Ore-forming Model ... (Pollard, 2001, 2006; Marschik](https://reader036.vdocuments.net/reader036/viewer/2022062600/5ac6852a7f8b9a333d8e7dcf/html5/thumbnails/28.jpg)
Basinal Brines for Cu (-Ag) mineralization at Mina Justa
Sulfur Isotope data
![Page 29: PACRIM 2015, Hong Kong The Mesozoic IOCG Deposits in the ... · The Mesozoic IOCG Deposits in the Central Andes A Refined IOCG Ore-forming Model ... (Pollard, 2001, 2006; Marschik](https://reader036.vdocuments.net/reader036/viewer/2022062600/5ac6852a7f8b9a333d8e7dcf/html5/thumbnails/29.jpg)
O-H isotopes of ore-forming fluids at Mina Justa
Magmatic fluids
Basinal Brines
![Page 30: PACRIM 2015, Hong Kong The Mesozoic IOCG Deposits in the ... · The Mesozoic IOCG Deposits in the Central Andes A Refined IOCG Ore-forming Model ... (Pollard, 2001, 2006; Marschik](https://reader036.vdocuments.net/reader036/viewer/2022062600/5ac6852a7f8b9a333d8e7dcf/html5/thumbnails/30.jpg)
System evolved under retrograde conditions. The incursion of fluids with isotopically heavy sulphur and light oxygen is evident from the intermediate to the late stages.
Magnetite Orthoclase Biotite Tourmaline Titanite Quartz Muscovite Chlorite Anhydrite Scapolite Rutile Epidote Hematite Pyrite Chalcopyrite Gold Siderite Calcite
STAGE I STAGE II ORE STAGE III STAGE IV K and Fe Chlorite-Muscov. Specular Hematite- Late calcite Metasomatism Quartz Chalcopyrite veins
500 to 550˚C δ34Sfluid~0‰ δ18Ofluid~+9‰
300 to 350˚C δ34Sfluid~+10 to +15‰ δ18Ofluid~+6 to +10‰
200 to 250˚C δ34Sfluid~ +25‰ δ18Ofluid~ +5‰
Basinal Brines for Cu (-Au) mineralization at Mantoverde
![Page 31: PACRIM 2015, Hong Kong The Mesozoic IOCG Deposits in the ... · The Mesozoic IOCG Deposits in the Central Andes A Refined IOCG Ore-forming Model ... (Pollard, 2001, 2006; Marschik](https://reader036.vdocuments.net/reader036/viewer/2022062600/5ac6852a7f8b9a333d8e7dcf/html5/thumbnails/31.jpg)
Basinal Brines for Cu (-Au) mineralization at Mantoverde (seawater ?)
δ18Ofluid
δDflu
id
Fluid mixing in ore stage
![Page 32: PACRIM 2015, Hong Kong The Mesozoic IOCG Deposits in the ... · The Mesozoic IOCG Deposits in the Central Andes A Refined IOCG Ore-forming Model ... (Pollard, 2001, 2006; Marschik](https://reader036.vdocuments.net/reader036/viewer/2022062600/5ac6852a7f8b9a333d8e7dcf/html5/thumbnails/32.jpg)
Compositional range for Fluid in equilibrium with Mt (500˚C)
Basinal Brines for Cu (-Au) mineralization at Mantoverde
From Alex Fitzpatrick (2008)
![Page 33: PACRIM 2015, Hong Kong The Mesozoic IOCG Deposits in the ... · The Mesozoic IOCG Deposits in the Central Andes A Refined IOCG Ore-forming Model ... (Pollard, 2001, 2006; Marschik](https://reader036.vdocuments.net/reader036/viewer/2022062600/5ac6852a7f8b9a333d8e7dcf/html5/thumbnails/33.jpg)
External fluids for Cu (-Au) mineralization at La Candelaria
Fluid inclusion A wide range of temperatures (200-450oC)
Ullrich and Clark (1997)
![Page 34: PACRIM 2015, Hong Kong The Mesozoic IOCG Deposits in the ... · The Mesozoic IOCG Deposits in the Central Andes A Refined IOCG Ore-forming Model ... (Pollard, 2001, 2006; Marschik](https://reader036.vdocuments.net/reader036/viewer/2022062600/5ac6852a7f8b9a333d8e7dcf/html5/thumbnails/34.jpg)
External fluids for Cu (-Au) mineralization at La Candelaria
From Ullrich and Clark (1999) Ullrich et al., 2001
δ34 S
δ18O
![Page 35: PACRIM 2015, Hong Kong The Mesozoic IOCG Deposits in the ... · The Mesozoic IOCG Deposits in the Central Andes A Refined IOCG Ore-forming Model ... (Pollard, 2001, 2006; Marschik](https://reader036.vdocuments.net/reader036/viewer/2022062600/5ac6852a7f8b9a333d8e7dcf/html5/thumbnails/35.jpg)
External fluids for Cu (-Au) mineralization at La Candelaria
Marschik and Kendrick, 2014
![Page 36: PACRIM 2015, Hong Kong The Mesozoic IOCG Deposits in the ... · The Mesozoic IOCG Deposits in the Central Andes A Refined IOCG Ore-forming Model ... (Pollard, 2001, 2006; Marschik](https://reader036.vdocuments.net/reader036/viewer/2022062600/5ac6852a7f8b9a333d8e7dcf/html5/thumbnails/36.jpg)
Summary of ore-forming fluids
1. magnetite stage fluids has higher temperatures and clear magmatic-hydrothermal features
2. Cu stage fluids show lower temperatures and signals of external fluids (e.g., seawater or basin brines)
![Page 37: PACRIM 2015, Hong Kong The Mesozoic IOCG Deposits in the ... · The Mesozoic IOCG Deposits in the Central Andes A Refined IOCG Ore-forming Model ... (Pollard, 2001, 2006; Marschik](https://reader036.vdocuments.net/reader036/viewer/2022062600/5ac6852a7f8b9a333d8e7dcf/html5/thumbnails/37.jpg)
To constrain a ore deposit model
Candelaria, Chile
1. Ore Deposit Geology
2. Paragenesis of alteration and mineralization
3. Nature of ore-forming fluids
Ore Deposit Model
![Page 38: PACRIM 2015, Hong Kong The Mesozoic IOCG Deposits in the ... · The Mesozoic IOCG Deposits in the Central Andes A Refined IOCG Ore-forming Model ... (Pollard, 2001, 2006; Marschik](https://reader036.vdocuments.net/reader036/viewer/2022062600/5ac6852a7f8b9a333d8e7dcf/html5/thumbnails/38.jpg)
Ore Genetic Model – Mina Justa
Chen et al., 2010
![Page 39: PACRIM 2015, Hong Kong The Mesozoic IOCG Deposits in the ... · The Mesozoic IOCG Deposits in the Central Andes A Refined IOCG Ore-forming Model ... (Pollard, 2001, 2006; Marschik](https://reader036.vdocuments.net/reader036/viewer/2022062600/5ac6852a7f8b9a333d8e7dcf/html5/thumbnails/39.jpg)
Ore Genetic Model – Mina Justa
Chen et al., 2010
![Page 40: PACRIM 2015, Hong Kong The Mesozoic IOCG Deposits in the ... · The Mesozoic IOCG Deposits in the Central Andes A Refined IOCG Ore-forming Model ... (Pollard, 2001, 2006; Marschik](https://reader036.vdocuments.net/reader036/viewer/2022062600/5ac6852a7f8b9a333d8e7dcf/html5/thumbnails/40.jpg)
Mantoverde: Ore Genetic Model
Mantoverde
ca. 130 Ma Benavides, 2006
![Page 41: PACRIM 2015, Hong Kong The Mesozoic IOCG Deposits in the ... · The Mesozoic IOCG Deposits in the Central Andes A Refined IOCG Ore-forming Model ... (Pollard, 2001, 2006; Marschik](https://reader036.vdocuments.net/reader036/viewer/2022062600/5ac6852a7f8b9a333d8e7dcf/html5/thumbnails/41.jpg)
Mantoverde: Ore Genetic Model
Benavides, 2006
Mantoverde
ca. 117 Ma
![Page 42: PACRIM 2015, Hong Kong The Mesozoic IOCG Deposits in the ... · The Mesozoic IOCG Deposits in the Central Andes A Refined IOCG Ore-forming Model ... (Pollard, 2001, 2006; Marschik](https://reader036.vdocuments.net/reader036/viewer/2022062600/5ac6852a7f8b9a333d8e7dcf/html5/thumbnails/42.jpg)
Ore Genetic Model – La Candelaria
Magmatic fluids
external fluids
IV
V
From Ullrich and Clark, 1999 Ullrich et al., 2001
![Page 43: PACRIM 2015, Hong Kong The Mesozoic IOCG Deposits in the ... · The Mesozoic IOCG Deposits in the Central Andes A Refined IOCG Ore-forming Model ... (Pollard, 2001, 2006; Marschik](https://reader036.vdocuments.net/reader036/viewer/2022062600/5ac6852a7f8b9a333d8e7dcf/html5/thumbnails/43.jpg)
![Page 44: PACRIM 2015, Hong Kong The Mesozoic IOCG Deposits in the ... · The Mesozoic IOCG Deposits in the Central Andes A Refined IOCG Ore-forming Model ... (Pollard, 2001, 2006; Marschik](https://reader036.vdocuments.net/reader036/viewer/2022062600/5ac6852a7f8b9a333d8e7dcf/html5/thumbnails/44.jpg)
Ore Genetic Model – Andean IOCG
Large Andean IOCG deposits and potentially related deposits, e.g., Manto-type Cu, CIB iron, small IOCG veins and porphyry Cu (Au-Mo)
S, Cu ?
![Page 45: PACRIM 2015, Hong Kong The Mesozoic IOCG Deposits in the ... · The Mesozoic IOCG Deposits in the Central Andes A Refined IOCG Ore-forming Model ... (Pollard, 2001, 2006; Marschik](https://reader036.vdocuments.net/reader036/viewer/2022062600/5ac6852a7f8b9a333d8e7dcf/html5/thumbnails/45.jpg)
Andean IOCG – not lonely
1
4 5
Kangdian
Eastern Tianshan
![Page 46: PACRIM 2015, Hong Kong The Mesozoic IOCG Deposits in the ... · The Mesozoic IOCG Deposits in the Central Andes A Refined IOCG Ore-forming Model ... (Pollard, 2001, 2006; Marschik](https://reader036.vdocuments.net/reader036/viewer/2022062600/5ac6852a7f8b9a333d8e7dcf/html5/thumbnails/46.jpg)
IOCG deposits in Eastern Tianshan
345-320 Ma intra-arc or back-arc basin 320-300 Ma inversion of basin
Important ore deposits formed during basin inversion, including Fe, Cu-Fe and some Ag-Cu deposits
![Page 47: PACRIM 2015, Hong Kong The Mesozoic IOCG Deposits in the ... · The Mesozoic IOCG Deposits in the Central Andes A Refined IOCG Ore-forming Model ... (Pollard, 2001, 2006; Marschik](https://reader036.vdocuments.net/reader036/viewer/2022062600/5ac6852a7f8b9a333d8e7dcf/html5/thumbnails/47.jpg)
Similar features to Andean IOCG deposits
1. Cu stage postdated magnetite and pyrite
2. magnetite stage has much higher temperatures (580oC) than Cu stage (170oC)
3.Cu stage ore-forming fluids are Ca-Mg dominated
Peak at 170 oC
![Page 48: PACRIM 2015, Hong Kong The Mesozoic IOCG Deposits in the ... · The Mesozoic IOCG Deposits in the Central Andes A Refined IOCG Ore-forming Model ... (Pollard, 2001, 2006; Marschik](https://reader036.vdocuments.net/reader036/viewer/2022062600/5ac6852a7f8b9a333d8e7dcf/html5/thumbnails/48.jpg)
Candelaria, Chile
Central Andean IOCG Deposit
Model
Can be applied to
Other districts on the Paleozoic continental
margins
We need more work… Eastern Tianshan
![Page 49: PACRIM 2015, Hong Kong The Mesozoic IOCG Deposits in the ... · The Mesozoic IOCG Deposits in the Central Andes A Refined IOCG Ore-forming Model ... (Pollard, 2001, 2006; Marschik](https://reader036.vdocuments.net/reader036/viewer/2022062600/5ac6852a7f8b9a333d8e7dcf/html5/thumbnails/49.jpg)
May you have a great Year of Goat !
and
Welcome to Guangzhou