Fluid overpressure and its relationship with the genesis of metal deposits

doi:10.13745/j.esf.sf.2025.7.26

Abstract

Abstract:

Fluid overpressure plays a key role in the formation of metal deposits. This paper presents the first systematic summary of the definitions and types of fluid overpressure, reporting three representative deposits closely associated with this mechanism: the Oulbulage porphyry Cu-Au deposit (Inner Mongolia), the Jinchuan magmatic Cu-Ni-(Pt) sulfide deposit (Gansu Province), and the Wuan Nanminghe iron deposit (Hebei Province). In the Oulbulage deposit, key evidence includes shock-induced textures in anisotropic garnet and phengite paragenetic with sulfides, which formed at 14.5 kbar. For the Jinchuan deposit, evidence includes dense radial fractures within early-formed sulfides and olivine. In the Wuan deposit, evidence comprises radial fractures in early-stage magnetite and plagioclase porphyry with multiple feldspar phenocrysts. Notably, cryptoexplosive breccias are widespread in all three deposits. Finally, the authors propose a fluid-overpressure-based mineralization prediction model that could significantly reduce exploration costs, and discuss key scientific challenges and future research directions.

Key words: fluid overpressure, porphyry copper-gold deposit, magmatic copper-nickel (platinum) sulfide deposit, Fe deposit

CLC Number:

P611

SU Shangguo, ZHANG Yanan, CHEN Xuegen, WANG Wenbo, LU Xin, LIU Cui, WANG Peng, WANG Yue, HAO Jinhua, YANG Zongfeng, XUE Song, CHEN Zhen, ZHANG Xinyan, LIU Yingtian, LI Mengtong, WANG Chengrui, CUI Xiaoliang, JIANG Xiao, ZHANG Bo, CUI Ying, LI Xiaowei, ZHAO Zhidan. Fluid overpressure and its relationship with the genesis of metal deposits[J]. Earth Science Frontiers, 2025, 32(6): 210-223.

Figures/Tables 10

Fig.1 Geological map of the Oubulage porphyry Cu-Au deposit. Modified after [7].

Fig.2 Characteristics of garnet in ores in Oubulage porphyry Cu-Au deposit

Fig.3 Relationship of anisotropic and isotropic garnet in Oubulage porphyry Cu-Au deposit

Fig.4 Characteristics of phengite in ores in Oubulage porphyry Cu-Au deposit

Fig.5 Fracture characteristics of minerals in the net and disseminated ores in the Jinchuan deposit

Fig.6 Fracture characteristics of sulfide in massive ores in the Jinchuan deposit

Fig.7 The magnetite mapping of Si element in massive ore in the Nanminghe Fe deposit

Fig.8 The trace elements spider diagram of magnetite (a) and the distribution diagram of REE (b) in the Nanminghe Fe deposit

Fig.9 Iron isotope composition of two types of magnetite in the Nanminghe deposit. Adapted from [48].

Fig.10 Exploration model diagram of metallic deposits

References 64

[1]	BOORMAN S L, MCGUIRE J B, ALAN E, et al. Fluid overpressure in layered intrusions: formation of a breccia pipe in the eastern bushveld complex, republic of South Africa[J]. Mineralium Deposita, 2003, 38(3): 356-369.
[2]	SU S G, Lu X, SANTOSH M, et al. Geochemical and Fe-isotope characteristics of the largest Mesozoic skarn deposit in China: implications for the mechanism of Fe skarn formation[J]. Ore Geology Review, 2021, 138: 104400.
[3]	TRAMONTANO S, GUALDA G A R, GHIORSO M S. Internal triggering of volcanic eruptions: tracking overpressure regimes for giant magma bodies[J]. Earth and Planetary Science Letters, 2017, 472: 142-151.
[4]	BHATTACHARYA P, VIESCA R C. Fluid-induced aseismic fault slip outpaces pore-fluid migration[J]. Science, 2019, 364(6439): 464-468.
[5]	TARLING M S, SMITH S A F, SCOTT J M. Fluid overpressure from chemical reactions in serpentinite within the source region of deep episodic tremor[J]. Nature Geoscience, 2019, 12(12): 1034-1042.
[6]	霍晓燕. 内蒙古欧布拉格铜金矿床的成矿特征与成矿机制[D]. 北京: 中国地质大学(北京), 2021.
[7]	ZHANG Y, XUE S, SU S, et al. Timing of S-saturation in the formation of the Oubulage porphyry Cu-Au deposit, Inner Mongolia, Northern China[J]. Journal of Asian Earth Sciences, 2025, 280: 106399.
[8]	张雅南. 内蒙古欧布拉格斑岩-矽卡岩铜金矿床新的成矿机制[D]. 北京: 中国地质大学(北京), 2025.
[9]	MASSONNE H, SZPURKA Z. Thermodynamic properties of white micas on the basis of high-pressure experiments in the systems K₂O-MgO-Al₂O₃-SiO₂-H₂O and K₂O-FeO-Al₂O₃-SiO₂-H₂O[J]. Lithos, 1997, 41(1/2/3): 229-250.
[10]	CHEN X, SU S, SANTOSH M, et al. The role of fluid overpressure in CuAu porphyry mineralization: evidence from the Oubulage deposit, Inner Mongolia, China[J]. Geochemistry, 2025: 126258.
[11]	LI C, NALDRETT A J, RIPLEY E M. Critical factors for the formation of a Ni-Cu deposit in evolved magmatic system: lessons from a comparison of the Pants Lake and Voisey’s Bay sulfide occurrences in Labrador[J]. Mineralium Deposita, 2001, 36: 85-92.
[12]	汤中立, 焦建刚, 闫海卿, 等. 小岩体成(大)矿理论体系[J]. 中国工程科学, 2015, 17(2): 4-18
[13]	汤中立, 钱壮志, 姜常义, 等. 中国镍铜铂岩浆硫化物矿床与成矿预测[M]. 北京: 地质出版社, 2006.
[14]	宋谢炎, 肖家飞, 朱丹. 岩浆通道系统与岩浆硫化物成矿研究新进展[J]. 地学前缘, 2010, 17(1): 153-163.
[15]	刘平平, 秦克章, 苏尚国. 新疆东天山图拉尔根大型铜镍矿床硫化物珠滴构造的特征及其对通道式成矿的指示[J]. 岩石学报, 2010, 26(2): 523-532.
[16]	秦克章, 田野, 姚卓森, 等. 新疆喀拉通克铜镍矿田成矿条件、岩浆通道与成矿潜力分析[J]. 中国地质, 2014, 41(3): 912-935.
[17]	苏尚国, 汤中立, 罗照华, 等. 岩浆通道成矿系统[J]. 岩石学报, 2014, 30(11): 3120-3130.
[18]	苏尚国, 汤中立. 岩浆通道成矿系统的理论与实践[J]. 矿床地质, 2010, 29(增刊1): 885-886.
[19]	MUNGALL J E, BRENAN J M, GODEL B, et al. Transport of metals and sulphur in magmas by flotation of sulphide melt on vapour bubbles[J]. Nature Geoscience, 2015, 8(3): 216-219.
[20]	LESHER C M. Up, Down, or Sideways: emplacement of magmatic Ni-Cu-(PGE) sulfide melts in large igneous provinces[J]. Canadian Journal of Earth Sciences, 2019, 56(7): 756-763.
[21]	LIU M Y, ZHOU M F, SU S G, et al. Contrasting geochemistry of apatite from peridotites and sulfide ores of the Jinchuan Ni-Cu sulfide deposit, NW China[J]. Economic Geology, 2021, 116(5): 1073-1092.
[22]	BARNES S J, YUDOVSKAYA M A, IACONO-MARZIANO G, et al. Role of volatiles in intrusion emplacement and sulfide deposition in the supergiant Norilsk-Talnakh Ni-Cu-PGE ore deposits[J]. Geology, 2023, 51(11): 1027-1032.
[23]	LI C, RIPLEY E M, NALDRETT A. A new genetic model for the giant Ni-Cu-PGE sulfide deposits associated with the Siberian flood basalts[J]. Economic Geology, 2009, 104(2): 29-301.
[24]	MAIER W D, LI C S, DEWAAL S A. Why are there no major Ni-Cu sulfide deposits in large layered mafic-ultramafic intrusions?[J]. The Canadian Mineralogist, 2001, 39(2): 547-556.
[25]	LESHER C M, CAMPBELL I H. Geochemical and fluid dynamic modeling of compositional variations in Archean komatiite-hosted nickel sulfide ores in Western Australia[J]. Economic Geology, 1993, 88(4): 804-816.
[26]	LIGHTFOOT P C, KEAYS R R. S saturation history of Nain Plutonic Suite mafic intrusions: origin of the Voisey’s Bay Ni-Cu-Co sulfide deposit, Labrador, Canada[J]. Mineralium Deposita, 2012, 47: 23-50.
[27]	NALDRETT A J, ASIF M, KRSTIC S, et al. The composition of ore at the Voisey’s Bay Ni-Cu sulfide deposit with special reference to platinum-group elements[J]. Economic Geology, 2000, 95: 845-866.
[28]	NALDRETT A J. Magmatic sulfide deposits: geology, geochemistry and exploration[M]. Berlin, Heidelberg: Springer-Verlag, 2004: 1-309.
[29]	汤中立, 李文渊. 金川铜镍硫化物(含铂)矿床成矿模式及地质对比[M]. 北京: 地质出版社, 1995: 1-209.
[30]	汤中立, 任端进. 中国硫化镍矿床类型及成矿模式[J]. 地质学报, 1987(4): 350-361.
[31]	汤中立. 甘肃金川铜镍硫化物(含铂)矿床模式及区域成矿预测[R]. 兰州: 甘肃省地矿局, 金川有色金属公司, 1993.
[32]	汤中立. 金川铜镍硫化矿床成矿模式[J]. 现代地质, 1990, 4(4): 55-64.
[33]	TANG Z L. Genetic model of the Jinchuan nickel copper deposit[J]. Geological Association of Canada Special Paper, 1993, 40: 389-401.
[34]	MUNGALL J, SU S G, WANG J, et al. Interfacial tension studies between Fe-Cu-Ni sulfide and halo-norilsk basalt slag system[J]. Science in China, 2005, 48(6): 834-839.
[35]	NALDRETT A J. World-class Ni-Cu-PGE deposits: key factors in their genesis[J]. Mineralium Deposita, 1999, 34(3): 227-240.
[36]	罗照华, 卢欣祥, 陈必河. 透岩浆流体成矿作用导论[M]. 北京: 地质出版社, 2009.
[37]	ROBERTSON J C, BARNES S J, LEVAILLANT M. Dynamics of magmatic sulphide droplets during transport in silicate melts and implications for magmatic sulphide ore formation[J]. Journal of Petrology, 2015, 56(12): 2445-2472.
[38]	苏尚国, 崔晓亮, 罗照华, 等. 流体晶、流体晶矿物组合、流体岩及其研究意义[J]. 地学前缘, 2018, 25(6): 283-289.
[39]	刘美玉, 苏尚国, 姚远, 等. 金川岩浆铜镍(铂)硫化物矿床中两类橄榄石的发现及其成矿意义[J]. 岩石学报, 2020, 36(4): 1151-1173.
[40]	陈学根, 苏尚国, 施南, 等. 金川岩浆铜镍(铂)硫化物矿床铂族金属富集过程及富集机制[J]. 地质学报, 2023, 97(11): 3715-3736.
[41]	MUNGALL J E, BRENAN J M. Experimental evidence for the chalcophile behavior of the halogens[J]. Canadian Mineralogist, 2003, 41: 207-220.
[42]	陈学根. 金川岩浆铜镍(铂)硫化物矿床铂族、钴等关键金属的富集过程及富集机制[D]. 北京: 中国地质大学(北京), 2025.
[43]	KESSEL R, SCHMIDT M W, ULMER P, et al. Trace element signature of subduction-zone fuids, melts and supercritical liquids at 120-180 km depth[J]. Nature, 2005, 437(7059): 724-727.
[44]	CHEN T N, CHEN R X, ZHENG Y F, et al. The effect of supercritical fluids on Nb-Ta fractionation in subduction zones: geochemical insights from a coesite-bearing eclogite-vein system[J]. Geochimica et Cosmochimica Acta, 2022, 335: 23-55.
[45]	NI H W, ZHANG L, XIONG X L, et al. Supercritical fluids at subduction zones: evidence, formation condition, and physicochemical properties[J]. Earth-Science Reviews, 2017, 167: 62-71.
[46]	彭湃. 金川岩浆铜镍(铂)硫化物矿床中块状矿石特征及成因[D]. 北京: 中国地质大学(北京), 2025.
[47]	连民杰, 张志献. 邯邢地区铁矿资源利用状况分析[J]. 矿业工程, 2006(1): 13-14.
[48]	鲁鑫. 矽卡岩铁矿床成矿新机制: 来自河北武安南洺河铁矿床证据[D]. 北京: 中国地质大学(北京), 2024.
[49]	DUPUIS C, BEAUDOIN G. Discriminant diagrams for iron oxide trace element fingerprinting of mineral deposit types[J]. Mineralium Deposita, 2011(4): 319-335.
[50]	NADOLL P, ANGERER T, MAUK J L, et al. The chemistry of hydrothermal magnetite: a review[J]. Ore Geology Reviews, 2014(61): 1-32.
[51]	DARE S A S, BARNES S J, BEAUDOIN G. Trace elements in magnetite as petrogenetic indicators[J]. Mineralium Deposita, 2014(7): 785-796.
[52]	GONH Q, LI F, LU C, et al. Tracing seawater- and terrestrial-sourced REE signatures in detritally contaminated, diagenetically altered carbonate rocks[J]. Chemical Geology, 2021, 570: 120169.
[53]	DARE S A, BARNES S J, BEAUDOIN G. Variation in trace element content of magnetite crystallized from a fractionating sulfide liquid, Sudbury, Canada: implications for provenance discrimination[J]. Geochimica et Cosmochimica Acta, 2012, 88: 27-50.
[54]	SUN S S, MCDONOUGH W F. Chemical and isotopic systematics of oceanic basalts: implications for mantle composition and processes[J]. Geological Society, London, Special Publication, 1989, 42(1): 313-345.
[55]	HELEN M W, CATHERINE A M, ANNE H P, et al. Iron isotope fractionation and the oxygen fugacity of the mantle[J]. Science, 2004, 304: 1656-1659.
[56]	NIE N X, SHAHAR A, NI P, et al. Equilibrium Fe isotope fractionation between olivine, pyroxene, spinel and MORB glass: implications for mantle partial melting to generate MORBs[J]. Geochimica et Cosmochimica Acta, 2025, 403: 130-151.
[57]	DAUPHAS N, ROSKOSZ M, ALP E E, et al. A general moment NRIXS approach to the determination of equilibrium Fe isotopic fractionation factors: application to goethite and jarosite[J]. Geochimica et Cosmochimica Acta, 2012, 94: 254-275.
[58]	TENG F Z, DAUPHAS N, HELZ R T. Iron isotope fractionation during magmatic differentiation in Kilauea Iki lava lake[J]. Science, 2008, 320(5883): 1620-1622.
[59]	TENG F Z, DAUPHAS N, HELZ R T, et al. Diffusion-driven magnesium and iron isotope fractionation in Hawaiian olivine[J]. Earth and Planetary Science Letters, 2011, 308(3/4): 317-324.
[60]	TENG F Z, DAUPHAS N, HUANG S, et al. Iron isotopic systematics of oceanic basalts[J]. Geochimica et Cosmochimica Acta, 2013, 107: 12-26.
[61]	SCHUESSLER J A, SCHOENBERG R, SIGMARSSON O. Iron and lithium isotope systematics of the Hekla volcano, Iceland: evidence for Fe isotope fractionation during magma differentiation[J]. Chemical Geology, 2009, 258(1/2): 78-91.
[62]	SOSSI P A, FODEN J D, HALVERSON G P. Redox-controlled iron isotope fractionation during magmatic differentiation: an example from the Red Hill intrusion, S. Tasmania[J]. Contributions to Mineralogy and Petrology, 2012, 164(5): 757-772.
[63]	TELUS M, DAUPHAS N, MOYNIER F, et al. Iron, zinc, magnesium and uranium isotopic fractionation during continental crust differentiation: the tale from migmatites, granitoids, and pegmatites[J]. Geochimica et Cosmochimica Acta, 2012, 97: 247-265.
[64]	刘璐璐, 苏尚国, 侯建光, 等. 河北武安坦岭多斑斜长斑岩的成因: 冻结岩浆房活化机制[J]. 岩石学报, 2017, 33(1): 204-220.