智利Caspiche金铜矿床地质特征、勘查过程及意义
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摘要
Caspiche斑岩型Au-Cu矿床是智利北部马里昆冈金-银-铜成矿带上的一个世界级矿床,也是南美洲近年来发现的最大矿床之一,矿床金储量约716 t,铜储量约266万t。该矿床发现历史漫长,先后有3家公司进行了长达21年的勘查工作,直到2007年才最终被发现。这样一个位于研究程度很高的成矿带上的世界级矿床,却经历了如此长的勘查周期,表明矿床本身及勘查工作一定具有其独特性,其经验对同类矿床的勘查必然具有重要参考意义。经对勘查过程的详细分析,总结其经验主要为:(1)地质条件与矿床类型的认识是勘查工作最重要的基础;(2)传统地质方法与现代计算机技术的结合是有效的勘查方法;(3)详尽的资料收集与分析可迅速缩小靶区,节省投入;(4)必要的资金投入是商业勘查成功的重要因素。
The Caspiche porphyry gold-copper deposit, a world class deposit of Maricunga gold-silver-copper belt of Northern Chile, is one of the largest deposits explored in South America in recent years.The reserves contain approximately atotal of 716 t of gold and 2.66 Mt of copper. It takes at least 21 years to explore in Caspiche until it was totally revealed by the Exeter Resource Corporation in 2007. The exploration experience in Caspiche is unique as the latest discovery in the Maricunga metallogenic belt, though widely explored in previous decades. Delayed recognition offers guidance for other deposits of the same type. This paper analyzes the exploration history of Caspiche in detail. There are four enlightening experiences:(1)detailed realization of geology and the mineralization;(2)proper combination of the traditional geology method and computer technology;(3)comprehensive survey of information;(4)imperative economic support.
The Caspiche porphyry gold-copper deposit, a world class deposit of Maricunga gold-silver-copper belt of Northern Chile, is one of the largest deposits explored in South America in recent years.The reserves contain approximately atotal of 716 t of gold and 2.66 Mt of copper. It takes at least 21 years to explore in Caspiche until it was totally revealed by the Exeter Resource Corporation in 2007. The exploration experience in Caspiche is unique as the latest discovery in the Maricunga metallogenic belt, though widely explored in previous decades. Delayed recognition offers guidance for other deposits of the same type. This paper analyzes the exploration history of Caspiche in detail. There are four enlightening experiences:(1)detailed realization of geology and the mineralization;(2)proper combination of the traditional geology method and computer technology;(3)comprehensive survey of information;(4)imperative economic support.
引文
[1]Van Kerkvoort G,Tolman J,Hernandez O.Caspiche porphyry Au-Cu deposit,Maricunga Belt,Chile:exploration,discovery and resource development[C]//2009 NewGenGold Conference,Perth,2009.http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.611.9084&rep=rep1&type=pdf.
[2]Vila T,Sillitoe R H,Betzhold J,et al.The porphyry gold deposit at Marte,northern Chile[J].Economic Geology,1991,86:1271-1286.
[3]Muntean J L,Einaudi M T.Porphyry gold deposits of the Refugio district,Maricunga belt,northern Chile[J].Economic Geology,2000,95:1445-1472.
[4]Palacios C,Hérail G,Townley B,et al.The composition of gold in the Cerro Casale gold-rich porphyry deposit,Maricunga belt,northern Chile[J].The Canadian Mineralogist,2001,39:907-915.
[5]Vila T,Sillitoe R H.Gold-rich porphyry systems in the Maricunga belt,northern Chile[J].Economic Geology,1991,86:1238-1260.
[6]Holley E A,Bissig T,Monecke T.The Veladero high-sulfidation epithermal gold deposit,El Indio-Pascua belt,Argentina:geochronology of alunite and jarosite[J].Economic Geology,2016,111:311-330.
[7]Jannas R R,Beane R E,Ahler B A,et al.Gold and copper mineralization in the El Indio deposit,Chile[J].Journal of Geochemical Exploration,1990,36:233-266.
[8]Chouinard A,Williams-Jones A E,Leonardson R W,et al.Geology and genesis of the multistage high-sulfidation epithermal Pascua Au-Ag-Cu deposit,Chile and Argentina[J].Economic Geology,2005,100:463-490.
[9]Cahill T,Isacks B L.Seismicity and shape of the subducted Nazca plate[J].Journal of Geophysical Research,1992,97(B12):17503-17529.
[10]Kay S M,Mpodozis C.Magmatism as a probe to the Neogene shallowing of the Nazca plate beneath the modern Chilean flat-slab[J].Journal of South American Earth Sciences,2002,15:39-57.
[11]Kay S M,Mpodozis C.Central Andean ore deposits linked to evolving shallow subduction systems and thickening crust[J].Geological Society of America Today,2001,11(3):4-9.
[12]Kay S M,Coira B,Mpodozis C.Field trip guide:neogene evolution of the central Andean Puna plateau and southern Central Volcanic Zone[R].Geological Society of America,Field Guide 13,2008:119-183.
[13]Kay S M,Mpodozis C,Tittler A,et al.Tertiary magmatic evolution of the Maricunga mineral belt in Chile[J].International Geology Review,1994,36:1079-1112.
[14]Sillitoe R H,Tolman J,Kerkvoort G V.Geology of the Caspiche porphyry gold-copper deposit,Maricunga belt,northern Chile[J].Economic Geology,2013,108:585-604.
[15]Arriagada C,Roperch P,Mpodozis C,et al.Paleomagnetism and tectonics of the southern Atacama Desert (25°-28°S),northern Chile[J].Tectonics,2006,25:TC4001.DOI:10.1029/2005TC001923.
[16]Mpodozis C,Clavero J.Tertiary tectonic evolution of the southwestern edge of the Puna plateau:cordillera Claudio Gay(26°-27°S),northern Chile[C]//Andean Geodynamics,5th International Symposium Toulouse,France.Paris:Inst.Rech.Dev.,2002:445-448.
[17]McKee E H,Robinson A C,Rybuta J J,et al.Age and Sr isotopic composition of volcanic rocks in the Maricunga belt,Chile:implications for magma sources[J].Journal of South American Earth Sciences,1994,7(2):167-177.
[18]Gustafson L B,Hunt J P.The porphyry copper deposit at El Salvador,Chile[J].Economic Geology,1975,70:857-912.
[19]Sillitoe R H,McKee E H,Vila T.Reconnaissance K-Ar geochronology of the Maricunga gold-silver belt,northern Chile[J].Economic Geology,1991,86:1261-1270.
[20]Sillitoe R H.Some thoughts on gold-rich porphyry copper deposits[J].Mineralium Deposita,1979,14:161-174.
[21]Sillitoe R H.Porphyry copper systems[J].Economic Geology,2010,105:3-41.
[22]Sillitoe R H.Gold-rich porphyry deposits:descriptive and genetic models and their role in exploration and discovery[J].Reviews in Economic Geology,2000,13:315-345.
[23]Sillitoe R H.Characteristics and controls of the largest porphyry copper-gold and epithermal gold deposits in the circum-Pacific region[J].Australian Journal of Earth Sciences,1997,44:373-388.
[24]Hedenquist J W,Arribas A J R,Reynolds T J.Evolution of an intrusion-centered hydrothermal system:far Southeast-Lepanto porphyry and epithermal Cu-Au deposits,Philippines[J].Economic Geology,1998,93:373-404.
[25]Muntean J L,Einaudi M T.Porphyry-epithermal transition:Maricunga belt,northern Chile[J].Economic Geology,2001,96:743-772.
[2]Vila T,Sillitoe R H,Betzhold J,et al.The porphyry gold deposit at Marte,northern Chile[J].Economic Geology,1991,86:1271-1286.
[3]Muntean J L,Einaudi M T.Porphyry gold deposits of the Refugio district,Maricunga belt,northern Chile[J].Economic Geology,2000,95:1445-1472.
[4]Palacios C,Hérail G,Townley B,et al.The composition of gold in the Cerro Casale gold-rich porphyry deposit,Maricunga belt,northern Chile[J].The Canadian Mineralogist,2001,39:907-915.
[5]Vila T,Sillitoe R H.Gold-rich porphyry systems in the Maricunga belt,northern Chile[J].Economic Geology,1991,86:1238-1260.
[6]Holley E A,Bissig T,Monecke T.The Veladero high-sulfidation epithermal gold deposit,El Indio-Pascua belt,Argentina:geochronology of alunite and jarosite[J].Economic Geology,2016,111:311-330.
[7]Jannas R R,Beane R E,Ahler B A,et al.Gold and copper mineralization in the El Indio deposit,Chile[J].Journal of Geochemical Exploration,1990,36:233-266.
[8]Chouinard A,Williams-Jones A E,Leonardson R W,et al.Geology and genesis of the multistage high-sulfidation epithermal Pascua Au-Ag-Cu deposit,Chile and Argentina[J].Economic Geology,2005,100:463-490.
[9]Cahill T,Isacks B L.Seismicity and shape of the subducted Nazca plate[J].Journal of Geophysical Research,1992,97(B12):17503-17529.
[10]Kay S M,Mpodozis C.Magmatism as a probe to the Neogene shallowing of the Nazca plate beneath the modern Chilean flat-slab[J].Journal of South American Earth Sciences,2002,15:39-57.
[11]Kay S M,Mpodozis C.Central Andean ore deposits linked to evolving shallow subduction systems and thickening crust[J].Geological Society of America Today,2001,11(3):4-9.
[12]Kay S M,Coira B,Mpodozis C.Field trip guide:neogene evolution of the central Andean Puna plateau and southern Central Volcanic Zone[R].Geological Society of America,Field Guide 13,2008:119-183.
[13]Kay S M,Mpodozis C,Tittler A,et al.Tertiary magmatic evolution of the Maricunga mineral belt in Chile[J].International Geology Review,1994,36:1079-1112.
[14]Sillitoe R H,Tolman J,Kerkvoort G V.Geology of the Caspiche porphyry gold-copper deposit,Maricunga belt,northern Chile[J].Economic Geology,2013,108:585-604.
[15]Arriagada C,Roperch P,Mpodozis C,et al.Paleomagnetism and tectonics of the southern Atacama Desert (25°-28°S),northern Chile[J].Tectonics,2006,25:TC4001.DOI:10.1029/2005TC001923.
[16]Mpodozis C,Clavero J.Tertiary tectonic evolution of the southwestern edge of the Puna plateau:cordillera Claudio Gay(26°-27°S),northern Chile[C]//Andean Geodynamics,5th International Symposium Toulouse,France.Paris:Inst.Rech.Dev.,2002:445-448.
[17]McKee E H,Robinson A C,Rybuta J J,et al.Age and Sr isotopic composition of volcanic rocks in the Maricunga belt,Chile:implications for magma sources[J].Journal of South American Earth Sciences,1994,7(2):167-177.
[18]Gustafson L B,Hunt J P.The porphyry copper deposit at El Salvador,Chile[J].Economic Geology,1975,70:857-912.
[19]Sillitoe R H,McKee E H,Vila T.Reconnaissance K-Ar geochronology of the Maricunga gold-silver belt,northern Chile[J].Economic Geology,1991,86:1261-1270.
[20]Sillitoe R H.Some thoughts on gold-rich porphyry copper deposits[J].Mineralium Deposita,1979,14:161-174.
[21]Sillitoe R H.Porphyry copper systems[J].Economic Geology,2010,105:3-41.
[22]Sillitoe R H.Gold-rich porphyry deposits:descriptive and genetic models and their role in exploration and discovery[J].Reviews in Economic Geology,2000,13:315-345.
[23]Sillitoe R H.Characteristics and controls of the largest porphyry copper-gold and epithermal gold deposits in the circum-Pacific region[J].Australian Journal of Earth Sciences,1997,44:373-388.
[24]Hedenquist J W,Arribas A J R,Reynolds T J.Evolution of an intrusion-centered hydrothermal system:far Southeast-Lepanto porphyry and epithermal Cu-Au deposits,Philippines[J].Economic Geology,1998,93:373-404.
[25]Muntean J L,Einaudi M T.Porphyry-epithermal transition:Maricunga belt,northern Chile[J].Economic Geology,2001,96:743-772.