【技术交流】世界级的斑岩型铜金矿床系统
本文原著者为：Nick Hayward/小编矿矿整理、翻译。
斑岩铜矿床的特征 Characteristicsof Porphyry Copper Deposits
较大的吨位，低品位Cu, Cu-Au, Cu-Mo-A
Large tonnage, low grade Cu,Cu-Au, Cu-Mo-Au
与俯冲相关的岩浆热液源，钙碱性-碱性至碱性的斑岩，氧化型（磁铁矿系列）侵入岩浆
Magmatic hydrothermal originin subduction related, porphyritic calc-alkaline to alkaline,oxidid I-type (magnetite ries) intrusions
矿化形成在地壳的1.5 - 5 km
Mineralisation forms at 1.5- 5 km crustal depth
在侵入体和围岩中含有网脉装的石英硫化物脉，浸染状的硫化物
Stockwork of quartz-sulphide veinletswithin intrusion and surrounding country rocks, and as disminated sulphides
与广泛的热液蚀变相关联
Associated with extensivehydrothermal alteration
Zonation reflects a hot, metal-richcore dominated by magmatic hydrothermal fluid (with stockwork veins), gradational withdistal zones of cooler fluid which mixed with meteoric waters. Meteoric fluids precipitate little or no newcopper and have no stockwork veining
图1 世界上斑岩型矿床的分布
图片5 全球的资源分布情况
CriticalProcess Model
SOURCE:
Subduction facilitated,oxidative enrichment of “depleted”lithosphere (old?)
Lithospheric melting in compressional tting to form S-undersaturated, oxidid I-type,calc-alkaline to alkaline magma
TRANSPORT:
Focusd ascent along trans-lithospheric, transpressional structure
Moderate degree of fractionation to enrichmetals in late stage int. to felsic melts
No assimilation of reduced quences
TRAP:
Focusd structural emplacement of porphyritic stocks to high crustallevels
Development of spanning cluster permeabilitybetween magma chamber and stock and focusd fluid flow into stockwork veins (PCD)
Vapour pha gregation and ascent ofCu-Au-As-Sb bearing plume into permeable volcanicstrata (HS epithermals)
MagmaChemistry vs Metal Content
Varying composition andoxidation states leads to different metal combinations:
