Isotope Systematics and Fluid Inclusion

Ore Geology Reviews 35 (2009) 245–261
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Ore Geology Reviews

j o u r n a l h o m e p a g e : w w w. e l s ev i e r. c o m / l o c a t e / o r e g e o r ev
Isotope systematics and fluid inclusion studies of the Qiyugou breccia pipe-hosted
gold deposit, Qinling Orogen, Henan province, China: Implications for ore genesis
Yan-jing Chen a,b, Franco Pirajno c,d,⁎, Nuo Li b, Dong-sheng Guo b, Yong Lai b
a
Key Laboratory for Metallogeny Dynamics, Guanzhou Institute of Geochemistry, Chinese Academy of Sciences, Guanzhou 510640, PR China
b
Open Laboratory of Orogen and Crustal Evolution, Peking University, Beijing 100871, PR China
c
Geological Survey of Western Australia, 100 Plain Street, East Perth, WA 6004, Australia
d
School of Earth and Geographical Sciences, The University of Western Australia, Crawley, WA 6009, Australia
a r t i c l e i n f o a b s t r a c t
Article history: The Qiyugou gold deposits, Henan Province, are hosted in breccia pipes within the Xiong'er terrane (Qinling
Received 30 June 2008 Orogen), on the southern margin of the North China Craton. In these deposits three paragenetic assemblages
Received in revised form 7 November 2008 have been recognized: an early K-feldspar–epidote–quartz–pyrite; a middle quartz-polymetallic sulfide; and a
Accepted 7 November 2008
late quartz–carbonate ± adularia. In this paper we review and interpret fluid inclusion and stable and
Available online 17 November 2008
radiogenic isotopic data of host rocks and ores. Fluid inclusions in quartz and calcite include water-rich, CO2-
Keywords:
rich, and daughter crystal-bearing. The CO2-rich and daughter mineral-bearing fluid inclusions are common in
Qinling Orogen the early-stage quartz and absent in the late-stage quartz and calcite which only contain water-rich fluid
North China Craton inclusions. Accordingly, the early-stage ore-fluids are magmatic in origin and characterized by high-
Breccia pipe temperature (N 350 °C), high-salinity (N 30 wt.% NaCl equiv.), and are CO2-rich. Fluid-boiling in the middle ore
Qiyugou stage resulted in CO2-release, decreasing oxygen fugacity and rapid precipitation of ore materials. The late stage
Gold deposit fluids, have low-temperature, low-salinity, are CO2-poor and lack daughter minerals. These fluids are probably
sourced from meteoric water. H–O–C isotope systematics confirm that, the ore–fluid system evolved from
magmatic to meteoric. The carbon and lead isotope ratios indicate that the Meso-Neoproterozoic sequence
south of the Xiong'er terrane was the likely source of the ore-forming materials. The Qiyugou breccia-pipes and
their associated gold ores were emplaced during an extensional regime following a transition from collision to
rifting tectonics, linked to collision and subduction of the Yangtze plate beneath the North China Craton.
Geochronological studies show that Mesozoic magmatism in the region occurred between the Triassic and
Cretaceous. The Triassic to Jurassic magmas were mostly derived from partial melting of ancient crust, whereas
the Cretaceous magmas show juvenile signatures, indicating mantle-derived components. Processes of
fragmentation of lithospheric roots, crustal and lithospheric thinning, extension and rifting were probably
associated with the subducting Pacific (Izanagi) plate. These crust–mantle geodynamic processes were
responsible for the development of anorogenic granitic melts that interacted with the Meso-Neoproterozoic
volatile-rich sedimentary successions, producing a flow of gas-rich hydrothermal fluids that resulted in the
emplacement of the Qiyugou auriferous breccia pipes. We conclude that the Qiyugou gold deposits are
intrusion-related explosive breccia pipe-type that evolved from hypothermal through mesothermal to
epithermal.
© 2008 Elsevier B.V. All rights reserved.
1. Introduction and regional geology metallogenic province are estimated at about 800 t, from about 55
orogenic lode deposits, placers and some 100 prospects, with a
A major metallogenic province endowed with considerable gold, production of 16.5 t/year (Mao et al., 2002; Yang et al., 2003). Porphyry
copper, lead, zinc and molybdenum resources is present in the and porphyry-skarn Mo and W deposits are part of this metallogenic
Xiong'ershan, Xiaoshan (Henan Province) and the Xiaoqinling (Shaanxi province and include the major Nannihu ore district with measured Mo
Province) regions, central China. This metallogenic province is located on metal resources in excess of 2.7 Mt (Li, 2005) and the Jinduicheng,
the southern margin of the North China Craton, along the tectonic Nannihu, Sandaozhuang, Shangfanggou and Dawanggou porphyry and
boundary with the Qinling orogenic belt (Fig. 1). Gold resources in this porphyry-skarn Mo–W deposits. In the same belt is the Leimengou
porphyry Mo deposit, spatially associated with the Qiyugou breccia
⁎ Corresponding author. Geological Survey of Western Australia, 100 Plain Street, East
pipes, and described in more detail below. Mao et al. (2008) recorded
Perth, WA 6004, Australia. three groups of molybdenite Re–Os ages from these porphyry systems,
E-mail address: franco.pirajno@doir.wa.gov.au (F. Pirajno). namely: 232–221 Ma; 148–138 Ma; and 133–112 Ma, which they
0169-1368/$ – see front matter © 2008 Elsevier B.V. All rights reserved.
doi:10.1016/j.oregeorev.2008.11.003
246 Y.J. Chen et al. / Ore Geology Reviews 35 (2009) 245–261
Fig. 1. Simplified regional geology of the Xiongershan–Waifangshan region, showing a range of selected mineral deposits; inset A shows the position of Fig. 1 in the Central China
Orogen; inset B shows a section of the Qinling Orogen, major structures in the region, SDF is Shangnan–Danfeng fault zone. After Chen et al. (2004).
attributed to a geodynamic evolutionary sequence from collisional 2004). The Qinling–Dabie Orogen was essentially formed during the
tectonics between the North China Craton and the Yangtze Craton, to collision and subduction of the Yangtze continental plate beneath the
a transitional tectonic regime with development of I-type granites at southern margin of the North China Orogen. It is not clear exactly
148–138 Ma, caused by subduction of the Paleopacific plate beneath the where is the suture boundary between the Yangtze and the North
eastern margin of Asia. The last event (133–112 Ma), according to Mao China Craton, but near the historical city of Xi'an, a geosuture marked
et al. (2008), is related to an extensional regime linked to lithospheric by the Shang–Dan (Shangnan–Danfeng) fault, possibly defines the
thinning and delamination. southern boundary of the Qinling Orogen (inset B of Fig. 1). Details of
The Qinling Orogen (also Qinling–Dabie or Kunlun–Qinling) is part the geodynamic evolution of the Qinling Orogen can be found in Zhang
of the wider Central China Orogen, which extends for more than et al. (1995), Meng and Zhang (2000) and Ratschbacher et al. (2003).
2000 km, separating the North China Craton from the South China As mentioned above, the Qinling Orogen was built during collision
Block (Fig. 1, inset A). To the east and against the Tanlu Fault, the orogen processes that sutured the Yangtze Craton with the North China
is called the Dabie belt, which is renowned for its ultrahigh pressure Craton, at about 450 Ma, when the intervening Shang Dan Ocean
mineral assemblages that include coesite and diamond (Bryant et al., closed, followed by the opening of the Mian-Lue Ocean splitting the
Y.J. Chen et al. / Ore Geology Reviews 35 (2009) 245–261 247
northern margin of the Yangtze Craton. Between 400 and 250 Ma the (Xiong'er Group) and Mesozoic igneous rocks (Chen et al., 2004). The
opening of the Mian-Lue Ocean and re-opening of the Shang–Dan Taihua Supergroup consists of greenstone rocks, mainly amphibolites
Ocean, led to the formation of Devonian–Middle Triassic flyschoid and (Beizi Group; N2.5 Ga) and metasedimentary rocks (graphitic schist,
volcanic rocks in the areas of the Shang–Dan fault, and of Late marble and iron formation units of the 2.3–2.2 Ga Shuidigou Group).
Carboniferous–Late Triassic coal-bearing sediments north of the San- The Xiong'er Group is a low-strain, low metamorphic grade and well-
Bao fault. In the Triassic to Late Jurassic (240–140 Ma), final closure of preserved volcanic succession with thicknesses ranging from 3 to
oceans and full-scale collision between the Yangtze and North China 7.6 km and an inferred present day areal extent of about 60,000 km2
continents occurred with intracontinental slab stacking, crustal (Zhao et al., 2002; Peng et al., 2008). The volcanic sequence
shortening and thickening. This was followed by extensional collapse unconformably overlies the metamorphic basement (Taihua Super-
of the Orogen during the Cretaceous, which in conjunction with group) and is overlain by Mesoproterozoic clastic and carbonate rocks
asthenospheric upwelling brought about the emplacement of crustal of the Ruyang Group and Guandaokou Group. The Xiong'er volcanic
melts (I- and A-type granitoids) within and along major crustal and rocks include basaltic andesite, andesite, trachyandesite, dacite,
lithospheric breaks in the Qinling Orogen. It is within this geodynamic rhyodacite and rhyolite, with minor sedimentary intercalations and
regime that metallogenic events occurred, resulting in the develop- pyroclastic units. The age of the Xiong'er Group and the associated
ment of important hydrothermal mineral systems in the region. We North China Dyke Swarm is reasonably well constrained at 1.78 Ga,
return to this topic in the last section. together constituting a large igneous province (LIP) that is probably
The Xiong'ershan region, situated on the southern margin of the related to a post-orogenic 1.8 Ga rifting event that affected the
North China Craton, along the Tieluzi–Luanchan fault zone, is southern margin of the North China Craton (Peng et al., 2005, 2008),
underlain by Neoarchaean (Taihua Supergroup), Palaeoproterozoic and forming a triple-junction rift system that could have separated the
Fig. 2. Simplified geological map of the Qiyugou–Leimengou area and position of selected breccia pipes. After Zhang (2006), Zhang et al. (2005, 2007).
Fig. 3. Photographs showing aspects of the Qiyugou breccia pipes; A) Open pit showing a steep boundary between breccia pipe and wallrocks of Taihua Supergroup. (B) Boundary
between breccia-pipe and clasts of brecciated metamorphic rocks. (C) Late stage carbonate vein and breccia ores mainly composed of K-feldspathized breccias. (D) Intensive K-feldspar
alteration.
North China Craton from the Dharwar Craton in India (Peng et al., molybdenite, and minor chalcopyrite, sphalerite, and galena. Three
2005; Hou et al., 2008). An alternative interpretation is that the stages of mineralization and temperature are recognized (Luo et al.,
Xiong'er Group developed in a volcanic arc related to the subduction 1991): 1) K-feldspar–quartz, 380–420 °C for quartz; 2) sulfide–quartz,
of the Kuanping Group (Hu, 1988; Chen and Fu, 1992; Zhao et al.,
2004; He et al., 2007).
The Mesozoic (Jurassic–Cretaceous) igneous rocks are mainly
granitoids, including several plutons, such as the Huashani monzogra-
nite, the Wuzhangshan pluton, quartz–feldspar porphyry intrusions,
dacite sills and dykes, diatremes and the Qiyugou breccia pipes that are
the subject of this paper. These Mesozoic intrusions have isotopic ages
ranging from 183 to 105 Ma and are related to the Yanshanian tectono-
thermal event (Chen and Fu, 1992; Chen et al., 2000, 2004; Mao et al.,
2002). More specifically, these intrusions appear to be post-orogenic
and associated with orogenic collapse and extensional tectonics (Yang
et al., 2003; Chen et al., 2004).
In the Xiong'ershan, a cluster of breccia pipes in the Qiyugou area
are spatially associated with the Leimengou porphyry Mo deposit, and
the Dagongyu Au deposit (Fig. 2). The Leimengou porphyry Mo
deposit is situated about 2 km west of Qiyugou (Figs. 1 and 2), with
reserves of 340,110 t Mo metal at a cut-off grade of 0.075% Mo (Mao
et al., 2008). The ore bodies are lensoid in shape and sub-horizontal
and are developed along the contact zone between the porphyry
granite and the gneissic rocks of Taihua Group (Luo et al., 1991). The
mineralized stocks are porphyritic fine-grained biotite granite and
hornblende monzonite. The porphyritic granite has a SHRIMP U–Pb
age of 137 ±2 Ma (Li, 2005) and its chemistry indicates that it belongs
to the alkaline series (Luo et al., 1991). Some breccia pipes are
developed along the margins or around the granite stock. Based on our
field visits, the deposit has typical stockworks developed in granitic rocks
with abundant molybdenite and pervasive hydrothermal alteration. The
potassic K-feldspar, quartz-sericitic and minor chlorite +argillic altera-
tion zones are recognized from the center of the intrusion stock towards Fig. 4. Schematic representation of sub-horizontal ore lenses in the Qiyugou breccia
the margins (Luo et al., 2000). Ore minerals are mainly pyrite, pipe; no particular orientation implied. After Zhang (2006).
350–410 °C for quartz and pyrite; 3) fluorite–sulfide and potassic-quartz, together with the available age determinations of ore materials and
290–385 °C for K-feldspar and fluorite. The isotopic composition of sulfur associated granitic rocks, allow us to propose a genetic model to
ranges from −2.8 to+3.72‰, average about +2.08‰ (Luo et al., 1991). explain the origin of the breccia pipes in the Qiyugou district.
Quartz fluid inclusions from the breccia cement show second boiling
temperature and salinity in the range from about 500 to 600 °C, and 5– 2. The Qiyugou Au-bearing breccia pipes
35 wt.% NaCl equiv., respectively (Luo et al., 2000).
The Qiyugou area, located 100 km south of the historical city of In the Qiyugou area at least seven breccia pipes are auriferous, with
Luoyang, contains 35 breccia pipes, which are clustered along E–W No. 2 and No. 4 being the main producers with total reserves of about
trending zones. Chen and Fu (1992) and Fan et al. (2000) proposed 40 t (Mao et al., 2002). Ore grades range from 3 to 5 g/t and can reach
that the formation of the Qiyugou Au-bearing breccia pipes was the values of up to 7 g/t (Mine staff, pers. comm., 2004). Higher gold
result of cryptoexplosions related to magmatic-hydrothermal activity. grades are present in zones of complex alteration and of greater clast
In this paper we use published stable (S, O–D, C) and radiogenic population (Mine staff, pers. comm., 2004). Gold has been mined in
(Pb) isotope systematics data combined with microthermometric the region since ancient times, reaching a peak during the Han
studies on fluid inclusions from the Qiyugou Au deposit which, dynasty about 2200 years ago (Gernet, 1999). The mineralisation of
Fig. 5. Photomicrographs of fluid inclusions; (A) Isolated S-type fluid inclusion containing daughter halite. (B) Isolated L-type fluid inclusion. (C) Opaque daughter mineral-bearing
S-type inclusion coexisting with L-type fluid inclusion. (D) C-type fluid inclusions comprising vapor CO2, liquid CO2 and liquid H2O. (E) V-type inclusions co-existing with C-type
fluid inclusion, which contains halite daughter mineral (H). (F) Coexisting V-, L- and S-types inclusions, implying for fluid boiling.
Table 1
Microthermometric data of fluid inclusions of the Qiyugou gold deposit.
Sample no. Ore stage FI type Num. Size Vapor T-h (°C) T-ice Salinity T-dmd Salinity T-clm Salinity
(μm) (vol.%) (°C) (wt.%NaCl eq) (°C) (wt.%NaCl eq) (°C) (wt.%NaCl eq)
QYG1 Early V, L, C 21 3–9 5–85 374–460 − 10.1 to −8.7 12.5–14.0 2.7–4.8 9.3–12.3
QYG2 Middle S, L 25 4–12 15–40 265–349 − 5.3 to − 2.5 4.2–8.3 105–208 28.1–32.3
QYG4 Early V, S, L 23 5–12 6–90 351–426 − 15.3 to − 7.0 10.5–18.9 177–288 30.6–37.2
QYG5 Middle S, V, L 12 5–16 15–85 287–335 − 7.2 to − 5.4 8.4–10.7 114–187 28.2–31.0
QYG3 Early V, L 8 5–18 15–70 368–443 − 16.5 to − 9.3 13.2–19.8
Late L 5 3–8 3–18 157–224 − 3.7 to − 2.3 3.7–6.0
QYG6 Early V, S, L 5 6–15 25–80 398–443 − 14.5 to − 9.8 13.7–18.2 161–189 30.1–31.4
Middle L, C 14 5–8 5–30 276–345 − 4.5 to − 3.4 5.6–7.2 5.2–7.5 4.8–8.7
Notation: clm, clathrate melting; dmd, daughter mineral dissolution.
the Qiyugou pipes has been previously reported by Chen et al. (1992), adularia, calcite and sericite. Field and textural evidences suggest that
Mao et al. (2002), Zhang (2006) and Zhang et al. (2005, 2007). In this the paragenetic sequence of this alteration is from green biotite +
paper, we focus on the Au deposits hosted by the No. 4 and No. 2 actinolite to epidote + chlorite + pyrite. The second sub-stage is
breccia pipes. represented by quartz, adularia with calcite and minor sericite. This
These breccia pipes and contained Au deposits are hosted in the alteration affects not only the breccia clasts, but also the matrix.
Taihua Supergroup on the west side of a Cenozoic basin bounded by Calcite is a late phase, and cuts quartz veins, clasts, and the cementing
Taocun–Mayuan fault (Fig. 1). Northwest- and NE-trending faults, the material. Adularia and calcite infill open spaces and/or fissures in
most important hosting structures, were formed by NE–SW and NW–SE pyrite, or form veins that cut altered clasts. Adularia with calcite are
compression in the Mesozoic (Gao et al., 1994). The pipes have a spindle commonly found in the 310 m, 370 m, 520 m levels and in the open pit
or elliptical shape in plan with long axes ranging from less than 40 m to of the No. 4 breccia pipe. Adularia + calcite are also observed in the No.
over a km and have been traced vertically for more than 300 m. The 2 breccia pipe. Textural relationships indicate that gold mineralization
breccia pipes contain clasts of Archaean basement rocks (migmatite, is paragenetically associated with adularia-calcite and pyrite.
gneiss and amphibolite), Palaeoproterozoic Xiong'er volcanic rocks and
Mesozoic granitic rocks (Fig. 3). The clasts range in size from a few cm to 4. Fluid inclusions
metres and have angular shapes with jigsaw-fit type breccia to round
shapes, suggesting multiple phases of volatile activity from hydraulic Microthermometric measurements were conducted using a LIN-
fracturing (jigsaw fit) to features typical of fluidization processes KAN THMSG600 heating–freezing stage in the State Key Laboratory
(e.g., rounded clasts; Zhang et al., 2007) (Fig. 3). of Lithospheric Evolution, Institute of Geology and Geophysics,
The contact between breccia pipes and wallrock is abrupt. Proximal
wallrocks of the breccia pipes were seismically cracked, forming
shatter rims several to tens of meters wide (Fan et al., 2000). Orebodies
are sited in the parts of the breccia pipes that are associated with faults.
The ores are associated with vein-like fine-grained metasomatic chert.
3. Mineralisation and hydrothermal alteration
The mineralization styles include vein, disseminations and stock-

works and the ore zones form sub-parallel sheets that are nearly
perpendicular to the pipe walls (Fig. 4). Most of the gold ore is
associated with sub-horizontal quartz veins that contain adularia
and pyrite. The principal ore minerals are pyrite, chalcopyrite, galena
and native gold. Sphalerite, electrum, molybdenite, chalcocite and
magnetite are present in lesser amounts. Shao and Li (1989) reported
the presence of Bi-sulfosalts and -sulfides. These minerals infill open
spaces between the breccia clasts. Gold is mainly found within the
fine-grained pyrite, both as inclusions and as fissure-fillings (Fig. 6).
Wallrock alteration consists of potassic and silica alteration, epidoti-
zation, sericitization, chloritization, carbonation, propylitization and
pyritization. Adularia, epidote and silica alteration mainly occur
within the breccia pipe, whereas propylitic alteration affects the
wallrock, thereby showing a clear zoning. In the breccia pipe,
alteration and gold mineralization of the matrix are more prominent
than in the breccia clasts. Potassic alteration (including K-feldspar,
adularia, biotite and sericite), silicification, and abundant sulfides
(especially pyrite) are generally indicative of good gold grades (Chen
and Fu, 1992). We have recognized two main styles of alteration. The
first is potassic and pre-dates gold mineralization, mainly affecting
gneisses and volcanic rocks and consisting of K-feldspar and quartz.
The second is exclusively confined to the pipes and comprises two
sub-stages: 1) pervasive; 2) vein and open space filling. The pervasive Fig. 6. Laser Raman spectra of water-rich inclusions, the CO2 signal appears in early-
stage consists of chlorite, actinolite, green biotite, epidote, quartz, stage inclusion (A), but not in the late-stage inclusion (B).
Table 2
Thermometric data of fluid inclusions of the Qiyugou deposit from previous studies.
Ore stage Inclusion combination T-h (°C) Salinity⁎ of V-L-type FIs Salinity⁎ of S-type FIs logfO2 Reference
Early V, V-L, S 368–476 12.85–17.61 31–42 Fan et al. (2000)
Middle V, V-L 310–390 5–7
Late L, V-L 109–289 2–3
Early V, V-L, S 298–470 N 47 − 28 to − 29 Xie et al. (1991)
Middle V-L 201–315 7–16 − 36 to − 38
Late L 130–240 0.7–1.5
Early V, V-L 380–480 18.1–24.2 − 23.70 to − 24.03 Gao et al. (1995)
Main V, V-L, S, C 250–390 10.7–19.3 30.5–33.5 − 26.98 to − 27.34
Late L 165–240 3.4–6.5 − 38.86 to − 41.64
Early 331.2–433.3 − 25.39 Wang and Li (1996)
Main 328–380 − 31.43
Late 174–272 − 39.98
I V, L 301.2–465.4 9.1–18.6 Qi et al. (2004)
II V, L, S, C 236.4–445.2 5.8–23.2 30.1–31.8
III S, C, L 243.9–372.6 4.7–23.0 30.8–37.2
IV L, S, C 183.1–335.7 4.8–21.7 28.2–31.9
V L 186.6–339.0 3.7–20.9
VI L 122.8–254.9 3.5–11.6
Early V, L, S, C 351–460 10.5–19.8 30.1–37.2 This paper
Middle V, L, S, C 265–349 4.2–10.7 28.1–32.3
Late L, V 157–244 3.7–6.0
Note: salinity is expressed in wt.% NaCl. equiv.
Chinese Academy of Sciences. The heating / freezing rate is generally LH2O or VCO2–LCO2–LH2O) and show round or oval shape. Larger
0.2–5 °C/min, but reduced to less than 0.2 °C/min near the phase size (5 to 15 μm) fluid inclusions can be observed although
transformation. The heating–freezing stage was calibrated using the most are very small. The carbonic phase occupies 10 to 85 vol.%
standard of synthetic fluid inclusions produced by America FLUID INC. of the inclusion. A few contain halite daughter-mineral (Fig. 5D,
Temperature errors are estimated at ±0.5 °C in the span of −120 °C to E) and were accordingly assigned to C-type.
−70 °C, and ±0.2 °C in the range between −70 °C and 500 °C. The
Quartz formed in different hydrothermal stages contains different
salinities of water-solution inclusions were calculated according to the
combination of fluid inclusions. The early- and middle-stages quartz
freezing temperature and using the equation provided by Bodnar
contain fluid inclusions of W-, S- and C-types; whereas the late-stage
(1993).
quartz only contains W-type fluid inclusions, including V- and L-
subtypes, although the L-subtype dominates over the V-subtype.
4.1. Petrography and types
4.2. Microthermometry
Three types of fluid inclusions were recognized in quartz and
calcite associated with the ore according to their composition and
Table 1 summarizes the microthermometric data. Three stages,
phase-transformation:
early, middle and late are recognised based on the homogenisation
(1) Water-rich inclusions (W-type). They are two-phase aqueous temperatures of fluid inclusions, which range from 351 to 460 °C, 265
inclusions, consisting of vapor and liquid water at room to 349 °C, and 157 to 244 °C, respectively, thus decreasing from early to
temperature, and can be divided into two subtypes, i.e. V- and late stages. Quartz formed in early and middle ore-forming stages
L-subtypes, according to their vapor to liquid ratio. The V-subtype
inclusions, with VH2O/(LH2O + VH2O) N 50% by volume, show
negative crystal or oval shapes and generally from 5 to 25 μm in
size. They occur isolated or coexist with the L-subtype inclusions.
The vapor bubbles are usually dark brown (Fig. 5) and contain
low proportions of CO2, N2, and CH4. The L-subtype inclusions,
with VH2O/(LH2O + VH2O) b 50 vol.%, ranging from 3 to 32 μm, and
round or irregular or occasionally negative shape. They occur
isolated or cluster along healed crystal fissures (Fig. 5B, C, E and F).
(2) Daughter mineral-bearing inclusions (S-type) are round and
with negative shape, and isolated, with size varying between 7
and 25 μm. Daughter minerals are dominantly cube-shaped
halite, and minor potassium chloride, pyrite, chalcopyrite and
hematite (Fig. 5A, C).
(3) CO2-rich fluid inclusions (C-type). Most of the C-type fluid
inclusions are two- or three-phase at room temperature (LCO2–
Table 3
Estimated trapping pressure of FIs of the Qiyugou gold deposit.
Reference This paper Xie et al. Gao et al. Wang and Qi et al.
(1991) (1995) Li (1996) (2004)
Fig. 7. δD–δ18O diagram of ore-fluids from the Qiyugou gold deposit (from Guo et al.,
Pressure (MPa) 22–45 20–40 25–40 51–101 29–50
2007). Details in text.
Table 4
The δ18O, δD (SMOW) and δ13C (PDB) values of the Qiyugou gold deposit.
No. Sample Mineral δ18OM δ18OW T/°C δD δ13CPDB Stage Reference

1 ZK6-31 Hornblende 6.2 8.9 470 − 65 Early Gao et al. (1994)
2 Q91-20 Chlorite 2.5 7.0 470 − 58 Early Gao et al. (1994)
3 XZ-26 Quartz 11.7 8.3 430 − 76 Early Xie et al. (1991)
4 XZ-01 Quartz 11.5 6.6 365 − 77 Early Xie et al. (1991)
5 Z-24-3 Quartz 11.5 7.7 410 − 62 Early Fan et al. (1994)
6 Z-25 Quartz 11.9 7.8 400 − 71 Early Fan et al. (1994)
7 Z-26 Quartz 11.7 7.6 400 − 68 Early Fan et al. (1994)
8 Q9801 Quartz 11.6 6.0 340 − 78 Early Fan et al. (2000)
9 Q9806 Quartz 11.8 6.5 350 − 68 Early Fan et al. (2000)
Average ± standard deviation (n = 9) 7.4 ± 0.9 404 − 69 ± 7 Early
10 Quartz 9.4 3.7 335 Middle Zhang (1985)
11 Quartz 12.0 6.3 335 Middle Zhang (1985)
12 6J2 Quartz 10.7 5.4 350 − 74 Middle Gao et al. (1994)
13 J2LQ4 Quartz 10.5 5.5 360 Middle Gao et al. (1994)
14 JLQ4 Quartz 10.5 4.6 330 Middle Gao et al. (1994)
15 J2Q2 Quartz 9.2 4.3 365 − 66 Middle Gao et al. (1994)
16 QJ2W1 Quartz 9.1 3.2 330 − 65 Middle Gao et al. (1994)
17 QF21 Quartz 12.5 6.0 310 Middle Gao et al., 1994
18 XZ-26 Quartz 11.7 4.0 280 − 68 Middle Xie et al., 1991
19 Z-01 Quartz 11.5 3.8 280 − 77 Middle Fan et al. (1994)
20 Z-24-3 Quartz 11.5 4.2 290 − 78 Middle Fan et al. (1994)
21 Z-25 Quartz 11.9 4.6 290 − 76 Middle Fan et al. (1994)
22 Q9804 Quartz 11.3 5.1 320 − 70 Middle Fan et al. (2000)
Average ± standard deviation (n = 13) 10.9 ± 1.1 4.7 ± 0.9 321 − 72 ± 5 Middle
23 Calcite 9.2 − 2.1 170 − 4.2 Late Shao and Li (1989)
26 C3 Calcite 9.1 − 2.2 170 − 4.2 Late Gao et al. (1994)
27 VCA3⁎ Calcite 9.5 − 1.8 170 − 2.1 Late Gao et al. (1994)
30 Calcite 9.9 − 1.4 170 Late Jin and Liu (1994)
Average ± standard deviation (n = 10) 8.4 ± 1.2 − 2.9 ± 1.2 170 − 3.5 ± 1.7
33 SRV7 Quartz 11.9 2.9 250 Late Gao et al. (1994)
34 J2L20 Quartz 10.4 1.4 250 − 74 Late Gao et al. (1994)
35 Quartz 10.1 − 1.9 196 Late Jin and Liu (1994)
36 Quartz 11.9 − 2.7 160 Late Jin and Liu (1994)
37 Q9860 Quartz 10.3 0.3 230 − 102 Late Fan et al. (2000)
Average ± standard deviation (n = 8) 11.2 ± 0.8 0.6 ± 1.9 222 − 81 ± 12 Late
Note: δ18OW of ore fluids in equilibrium with calcite and quartz are calculated according to formulas of 1000lnαquartz–water = 3.38 × 106 / T2 − 3.4 (Clayton et al., 1972) and
1000lnαcalcite–water = 2.78 × 106 / T2 − 2.89 (O'Neil et al., 1969) respectively. Measured homogeneity temperatures or peak temperatures of different ore stages are used to calculate.
Samples with ⁎ denote disseminated ores.
contains co-existing V-, L- and S-types fluid inclusions (Fig. 5E, F). clathrate melting points range from 9.3 to 12.3 wt.% NaCl equiv. for the
Some of these fluid inclusions homogenized to contrasting to liquid early stage, and from 4.8 to 8.7 wt.% NaCl equiv. for the middle stage
and vapor, at similar temperatures during heating, implying that ore- (Table 1), showing similar change to those shown by the S- and W-
fluids boiled in the early and middle stages. types fluid inclusions. In other words, the salinities of ore-fluids
The fluid inclusions in the early-stage quartz crystals are mainly of consistently decrease from early to late stages.
the S-type. During heating halite daughter minerals usually dissolved Trapping pressure of CO2-rich fluid inclusions of the early and
before the vapor-bubble disappeared. Dissolution temperatures of middle stages was estimated to be 22–45 MPa, according to partial
halite range between 161 and 288 °C and the estimated salinities and total homogeneous temperatures and the phase-transformation
range from 30.1 to 37.2 wt.% NaCl equiv. (Table 1). In middle stage diagram for H2O–CO2 system of Schwartz (1989). This estimate is
quartz a few S-type fluid inclusions are observed. Their daughter similar to the pressure measured for porphyry ore-systems (Seedorff
halite dissolved at temperatures of between 114 and 187 °C, yielding et al., 2005; William-Jones and Heinrich, 2005), and suggests that the
estimated salinities ranging from 28.1 to 31.0 wt.% NaCl equiv. mineralization depth ranges from 2.2 to 4.5 km under hydrostatic
(Table 1), which are lower than those of the early stage. In late pressure. The mineralization depth is therefore deeper than that of
minerals no S-type inclusions was observed, suggesting that the epithermal systems, which generally develop at depths shallower
late stage fluid was a diluted fluid. Freezing temperatures of fluid than 2 km (Kerrich et al., 2000; White, 2003).
inclusions were measured between −16.5 to −7.0 °C, − 7.2 to −2.5 °C
and −3.7 to −2.3 °C for the early, middle and late stages, respectively. 4.3. Laser Raman spectra
Their corresponding salinities were estimated in the ranges of 10.5–
19.8 wt.% NaCl equiv, 4.2–10.7 wt.% NaCl equiv. and 3.7–6.0 wt.% NaCl Compositions of single fluid inclusions were identified using RM-2000
equiv., respectively, also suggesting a gradual dilution from early to Laser Raman probe (Britain Renishaw Company), in the Key Laboratory of
late. Salinities of CO2-rich fluid inclusions estimated according to CO2 Lithospheric Evolution, Institute Geological and Geophysical Chinese
Table 5
δ34S of ores and rocks from the Qiyugou gold deposit.
No. Sample description Mineral δ34S Reference

1 Breccia ore (J2L119) Chalcopyrite − 0.7 Gao et al. (1994)
2 Breccia ore (J2S3-1) Chalcopyrite − 1.1 Gao et al. (1994)
3 Breccia ore (J2-2) Chalcopyrite − 2.0 Gao et al. (1994)
4 Breccia ore (J2L119) Galena − 1.5 Gao et al. (1994)
5 Breccia ore (J2Pb) Galena − 2.1 Gao et al. (1994)
6 Breccia ore (J2S2-2) Galena − 3.5 Gao et al. (1994)
7 Breccia ore (BJ2) Galenobismuthite − 1.7 Gao et al. (1994)
8 Breccia ore (QJ2W1) Pyrite − 0.2 Gao et al. (1994)
9 Breccia ore (2J2-1) Pyrite − 0.2 Gao et al. (1994)
10 Breccia ore (J2Q2) Pyrite 0.3 Gao et al. (1994)
11 Breccia ore (BJ2) Pyrite 0.2 Gao et al. (1994)
12 Breccia ore (J2L119) Pyrite 0.9 Gao et al. (1994)
13 Breccia ore (J2L129) Pyrite − 0.2 Gao et al. (1994)
14 Breccia ore (J2S2-1) Pyrite − 0.7 Gao et al. (1994)
15 Breccia ore (J2S3-2) Pyrite − 0.8 Gao et al. (1994)
16 Breccia ore (QJ2-5) Pyrite 0.2 Gao et al. (1994)
17 Breccia ore (J2L20) Pyrite − 0.5 Gao et al. (1994)
18 Disseminated ores (QP3) Chalcopyrite 0.9 Gao et al. (1994)
19 Disseminated ores (VCV-23) Galena 0.6 Gao et al. (1994)
20 Disseminated ores (1P3D) Galena 0.1 Gao et al. (1994)
21 Disseminated ores (QP3) Galena 0.8 Gao et al. (1994)
22 Disseminated ores (VCV-26) Pyrite 1.7 Gao et al. (1994)
23 Disseminated ore (1P4) Pyrite 1.7 Gao et al. (1994)
24 Disseminated ore (1P3B) Pyrite 0.7 Gao et al. (1994)
25 Disseminated ore(1P3D) Pyrite 2.5 Gao et al. (1994)
26 Disseminated ore (QP3) Pyrite 2.2 Gao et al. (1994)
27 Disseminated ore (1P3E) Pyrite 0.8 Gao et al. (1994)
28 Disseminated ore (Q91-1) Pyrite 1 Gao et al. (1994)
29 Disseminated ore (Q91-2) Pyrite − 0.5 Gao et al. (1994)
30 Ore (XQ-1) Pyrite − 0.3 Fan et al. (1994)
36 Ore (XQ-14) Pyrite 0.0 Fan et al. (1994)
Average ± standard deviation (n = 43) − 0.2 ± 1.3
44 Volcanic rocks, Xiong'er Gp. Pyrite 3.6 Chen et al. (2004)
45 Amygdaloidal andesite, Xiong'er Gp. (SH6-3) Pyrite 4.3 Chen et al. (2004)
46 Amygdaloidal andesite, Xiong'er Gp. (SH-22) Pyrite 4.6 Chen et al. (2004)
47 Amygdaloidal megaphyric andesite, Xiong'er Gp. Pyrite 2.5 Chen et al. (2004)
48 Andesite, Xiong'er Gp. Pyrite 5.4 Chen et al. (2004)
Average ± standard deviation (n = 5) 4.1 ± 1.1
49 Biotite plagiogneiss, Taihua Supergroup Pyrite 5.7 Chen et al. (2004)
50 Amphibolite, Taihua Supergroup Pyrite 2.9 Chen et al. (2004)
53 Haoping granite of Huashan complex Pyrite 2.7 Chen et al. (2004)
54 Adamellite of Huashan complex Pyrite 2.3 Chen et al. (2004)
55 Adamellite of Huashan complex Pyrite 1.8 Chen et al. (2004)
56 Biotite granite of Huashan complex Pyrite 5.4 Chen et al. (2004)
Academy of Sciences. The wavelength of Ar+ laser is 514 nm and the 4.4. Nature and evolution of ore-forming fluid
measured spectrum time is 10 s. Counting rate is one time per cm. The
spectrum diagram is taken from the wave band of 100–4000 cm− 1. The Table 2 lists thermometric data reported in previous studies
size of laser beam spot is 1 mm and the resolution is 2/cm. (references cited therein). All the researchers classified the ore-forming
The liquid phase of early-stage water-rich inclusion gives a spectra process into three stages except for Qi et al. (2004), who divided the ore-
diagram characteristic of peaks of CO2 (1386 and 1284 cm− 1) in forming process into six stages, but with overlapping homogenization
addition to peaks of host quartz and liquid H2O (3310–3610 cm− 1) temperatures. These microthermometric results as reported by different
(Fig. 6A), showing that trapped inclusions contain variable proportions researchers are consistent and summarized below:
of CO2. However, the spectra diagram for liquid phase of late-stage
water-rich inclusion does not show CO2 (Fig. 6B). This would indicate (1) The types of fluid inclusions that were recognized include vapor-
that CO2 must have escaped from the ore-forming fluid-system. dominant water-rich (V-type), liquid-dominant water-rich (L-
Table 6
Lead isotope ratios of ores and associated rocks from the Qiyugou deposit.
206
No. Geology of ore or rocks Sample no. Mineral Pb/204Pb 207
Pb/204Pb 208
Pb/204Pb Reference
1 Granite porphyry breccia Qi-6 Galena 17.219 15.405 37.512 Zhang (1985)
2 Explosive breccia Qi-13 Galena 17.259 15.474 37.378 Zhang (1985)
3 Explosive breccia Qi-43 Galena 17.259 15.474 37.696 Zhang (1985)
4 Granite porphyry breccia N-6 Galena 17.740 15.820 38.980 Zhang (1985)
5 Polymetallic ore Qi-4 Galena 18.078 15.484 37.370 Zhang (1985)
6 Ore ZK033-168 Pyrite 17.272 15.437 37.660 Tang (1988)
9 Ore BP2T-58 Pyrite 17.335 15.495 37.805 Tang (1988)
10 Ore BP2-3d Pyrite 17.202 15.425 37.380 Tang (1988)
11 Ore BP2-1d Pyrite 17.386 15.472 37.770 Tang (1988)
12 Ore BP2T-5 Pyrite 17.342 15.483 37.737 Tang (1988)
13 Ore J2 Galena 17.443 15.619 38.090 Shao (1992)
14 Ore J4 Galena 17.282 15.481 37.776 Shao (1992)
15 Ore J4 Galena 18.530 16.620 40.760 Shao (1992)
16 Ore N6 Galena 17.730 15.820 38.980 Shao (1992)
17 Ore Qy-56 Galena 17.177 15.371 37.464 Luo and Guan (1995)
21 Ore Chalcopyrite 17.080 15.257 37.192 Cui (1991)
22 Ore Chalcopyrite 17.139 15.303 37.145 Cui (1991)
23 Disseminated ore HP1 Galena 17.290 15.478 37.823 Gao et al. (1994)
24 Disseminated ore HP2 Galena 17.252 15.425 37.653 Gao et al. (1994)
Average ± standard deviation (n = 27) Ores 17.386 ± 0.354 15.535 ± 0.272 37.871 ± 0.781
25 granite porphyry dyke K-feldspar 17.415 15.379 38.674 Cui (1991)
26 granite porphyry dyke Whole rock 17.271 15.278 37.265 Cui (1991)
27 Granite R5A K-feldspar 17.440 15.570 39.970 Gao et al. (1994)
28 Granite R5B K-feldspar 17.199 15.391 37.477 Gao et al. (1994)
29 granite porphyry BP3-Q1 Whole rock 17.231 15.278 37.265 Tang (1988)
30 granite porphyry BP3-Q2 Whole rock 17.562 15.344 37.822 Tang (1988)
31 Granite K-feldspar 17.440 15.520 37.975 Shao (1992)
32 Granite K-feldspar 17.473 15.455 37.886 Shao (1992)
Average ± standard deviation (n = 8) Porphyry 17.379 ± 0.129 15.402 ± 0.107 38.042 ± 0.904
type), daughter mineral-bearing (S-type) and CO2-rich (C-type). (6) Table 3 lists estimated trapping pressure of fluid inclusions of
The late-stage minerals only contain water-rich inclusions. the Qiyugou gold deposits. Again different researchers got
(2) The estimated oxygen fugacities (logfO2) of the ore-fluids similar results, i.e. trapping pressure ranging from 20 to
decreased from early to middle stages (Table 2). This is 50 MPa, with corresponding hydrostatic depths ranging from
supported by the fact that hematite daughter-minerals are 2 to 5 km. The high end-member pressure is 2.5 times of the
present in the early-stage S-type fluid inclusions (Xie et al., low end-member, analogous to density discrepancy between
1991; Gao et al., 1995), and that most of sulfides were supracrustal rocks (ca. 2.5 g/cm3) and water, suggesting that
precipitated in the middle ore stage. the pressure of the fluid-system changed from lithostatic to
(3) Estimates of fluid salinities show that the ore-fluids were hydrostatic at a depth of ca. 2 km. The only exception is made by
gradually diluted from early to late, which accord with the Wang and Li (1996) whose estimated pressure is higher than
findings of our study. Salinities of the S-type fluid inclusions in the others. However, Wang and Li's estimates are not
quartz of early and middle ore stages are as high as N30 wt.% acceptable because they did not report the methodology used.
NaCl equiv., and up to N47 wt.% NaCl equiv., indicating that the
initial ore-fluids was likely sourced from a magmatic system. To summarize, the initial ore-fluids are CO2-rich, high-tempera-
(4) Previous measurements show that fluid inclusions of early, ture, high-salinity and high-fO2 and likely magmatic in origin. Fluid-
middle and late stages homogenized in temperature ranges boiling, possibly characteristic of CO2-escape, resulted in decrease in
of 298–476 °C, 201–390 °C, 109–290 °C, respectively. This is temperature, salinity and fO2, and rapid precipitation of ore-forming
similar to the results obtained in our study, supporting our materials. Boiling-related hydrofractures were open and connected to
contention that the Qiyugou hydrothermal fluid-system began the surface, leading to inflow of voluminous meteoric-water into and
as a hypothermal intrusion-related ore system that subse- its mixing with the intrusion-related hypothermal fluid-system. The
quently evolved towards meso- and epithermal stages with ore-fluid system became low-temperature, low-salinity and CO2-poor.
cooling and the influx of meteoric waters in the final stages. These conclusions are further supported by studies in isotope
(5) CO2-rich (C-type) fluid inclusions can be recognized in the geochemistry (Fig. 7; Guo et al., 2007). The fluid inclusions studies
early and middle stages but not in late stage (Table 2). Laser show that ore fluids temperatures cluster in three ranges of 350 °C to
Raman analysis detected a certain amount of CO2 contained in 470 °C, 250 °C to 345 °C and 150 °C to 250 °C (this work).
liquid phase of early-stage water-rich fluid inclusions (Fig. 6A),
but not in late-stage fluid inclusions (Fig. 6B). This implies that 5. Isotope systematics
the ore-fluids evolved from CO2-rich to CO2-poor. This conclu-
sion is supported by the early-stage anhydrous alteration, Stable and radiogenic isotopic compositions for ore materials, host
represented by K-feldspar and epidote (Fig. 4C, D), instead of rocks and associated granites, sourced from the literature and our
hydrous minerals such as chlorite and sericite, which are work are presented in Tables 4 (O, D and C), 5 (S), 6 and 7 (Pb ratios).
common in the middle and late mineral assemblages. The data are discussed below.
Table 7
Lead isotope ratios of the main geologic bodies in the Xiong'er terrane.
206
No. Sample description Testing object Pb/204Pb 207
Pb/204Pb 208
Pb/204Pb Reference
Huashan complex
1 Biotite monzonitic granite Whole rock 17.476 15.418 37.832 Luo, 1992
5 Biotite monzonitic granite K-feldspar 17.440 15.520 37.975 Luo, 1992
8 Biotite monzonitic granite K-feldspar 17.420 15.381 37.660 Cui (1991)
9 Biotite monzonitic granite K-feldspar 17.150 15.318 37.240 Cui (1991)
10 Biotite monzonitic granite K-feldspar 17.469 15.425 37.660 Chen, 1995
15 Biotite monzonitic granite K-feldspar 17.745 15.412 37.983 Wang et al., 1997
Average ± standard deviation (n = 15) 17.551 ± 0.275 15.436 ± 0.062 37.794 ± 0.303
Taihua Supergroup
16 Amphibolite Whole rock 17.322 15.620 37.973 Li and Ren, 1990
17 Biotite plagiogneiss Whole rock 17.373 15.420 40.447 Li and Ren, 1990
18 Coarse-grained migmatite Whole rock 16.892 15.203 37.242 Li and Ren, 1990
19 K-feldspar pegmatite Whole rock 16.368 15.192 35.902 Li and Ren, 1990
20 Amphibole gneiss Whole rock 17.530 15.345 38.569 Cui (1991)
21 Gneiss Whole rock 17.495 15.279 37.839 Cui (1991)
22 Biotite gneiss Whole rock 17.400 15.469 38.174 Cui (1991)
23 Amphibole gneiss Whole rock 17.162 15.504 37.746 Shao, 1992
24 Migmatite Magnetite 17.475 15.504 40.427 Shao, 1992
25 Amphibole gneiss K-feldspar 15.788 15.351 36.476 Shao, 1992
26 amphibole gneiss Whole rock 19.428 15.667 41.260 Luo, 1992
27 Biotite gneiss Whole rock 17.353 14.492 42.558 Fan et al., 1994
28 Amphibolite Whole rock 16.968 15.359 37.775 Fan et al., 1994
29 Amphibolite Whole rock 17.609 15.547 37.654 Fan et al., 1994
30 Biotite gneiss Whole rock 15.406 15.188 37.526 Fan et al., 1994
31 Biotite-amphibole gneiss Whole rock 16.511 15.512 36.266 Fan et al., 1994
Average ± standard deviation (n = 16) 17.130 ± 0.893 15.353 ± 0.273 38.365 ± 1.867
Xiong'er group
32 Xiong'er group (n = 2) Whole rock 17.322 15.620 37.973 Zhang et al., 2002
33 Megaphyric andesite Whole rock 17.373 15.420 40.447 Luo, 1992
34 Andesite Whole rock 16.892 15.203 37.242 Luo, 1992
35 Amygdaloidal andesite Whole rock 16.368 15.192 35.902 Luo, 1992
36 Diorite porphyrite Whole rock 17.530 15.345 38.569 Luo, 1992
37 Diorite porphyrite Whole rock 17.495 15.279 37.839 Zhao, 2000
38 High-K basaltic andesite Whole rock 17.400 15.469 38.174 Zhao, 2000
39 trachyandesite Whole rock 17.162 15.504 37.746 Zhao, 2000
40 High-K andesite Whole rock 17.475 15.504 40.427 Zhao, 2000
Average ± standard deviation (unaltered) (n = 8) 16.532 ± 0.377 15.331 ± 0.148 36.786 ± 1.445
5.1. Hydrogen and oxygen 5.2. Carbon
Hydrogen and oxygen isotopes are important monitors of the Three calcite samples of the late stage phase have δ13CPDB of −4.2
character and evolution of ore fluids. The oxygen isotope ratios of to −5.8‰ and average − 5.0‰. Three calcite samples of late ore stage
waters in equilibrium with the minerals are calculated using the disseminated ores show δ13CPDB of −1.6 to −4.2‰, and average
fractionation formulas from Clayton et al. (1972) for quartz, and from − 2.4‰. These δ13C values are significantly higher than carbon
O'Neil et al. (1969) for calcite. The results show that the δ18O of early reservoirs, such as organic matter (− 27‰), atmospheric CO2 (−8‰,
ore stages range between 6.0 to 8.9‰, with an average of 7.4‰; and Schidlowski, 1998), dissolved CO2 in fresh water (− 9 to −20‰, Hoefs,
the δD values vary between − 58 and − 78‰ and an average of 1997), continental crust (−7‰, Faure, 1986), but are similar to or
− 69‰. These values all plot in the magmatic water box (Fig. 7). The slightly higher than those of mantle (−5 to −7‰, Hoefs, 1997) or
δ18OW of the middle stages range from 3.2 to 6.3‰ with an average of igneous rocks (−3 to −30‰, Hoefs, 1997). This indicates that CO2 of
4.7‰; δD values range from − 65 to − 78‰ with an average of − 72‰, ore fluids were probably sourced from a magmatic system, perhaps
which are lower than those of the early stage suggesting input of and/ with some input from metamorphic decarbonation of carbonate
or interaction with meteoric water (Fig. 7). The calculated δ18OW in strata (δ13C = 0.5‰) (Chen et al., 2005, 2006; Qi et al., 2005).
equilibrium with late-stage quartz range between − 2.7 and 2.9‰
with an average of 0.6‰; the calculated δ18OW in equilibrium with 5.3. Sulfur
calcite vary between − 5.1 and − 1.4‰ with an average of − 2.9‰.
These values are typical of meteoric water. Data points from early to The δ34S ratios of the ores range between − 3.5 and 2.5‰, largely
late stages shift from the magmatic water box towards the meteoric clustering between −1 and 1‰, and averaging −0.2‰, showing a
water line (Fig. 7). pronounced normal distribution (Fig. 8). The narrow range of sulfur
Shanggong gold deposit (δ34S = −14.6–6.3‰; Chen et al., 2006,

2008), Tieluping silver deposit (δ34S = − 8.8 to − 0.6‰; Chen et al.,
2004), Kangshan gold deposit (δ34S = −0.2–5.4‰, with an average of
2.8‰; Wang et al., 2001a,b) all in the Xiong'er terrane, the Qinyugou
breccia pipe gold deposits have a narrower δ34S range, mostly close to
zero, implying a magmatic control on the mineralizing event.
5.4. Lead
The ores have lead isotope ratios of 206Pb/204Pb from 16.771 to

18.530, with an average of 17.386; 207Pb/204Pb from 15.257 to 15.820,
with an average of 15.535. The Qiyugou granite porphyries have 206Pb/
204
Pb ratios between 17.199 and 17.562, with an average of 17.379, and
207
Pb/204Pb ratios between 15.278 and 15.570, with an average of
15.402. In Fig. 9, Pb isotope data plot across upper crust, orogen, mantle
and lower crust lines (Zartman and Doe, 1981), with most clustering
near the mantle line, indicating complex lead sources. Pb isotopic data
from the ores, porphyry, breccias and biotite granite largely fall in the
data range of the Taihua Group. Most Pb isotope data of K-feldspar in
the Qiyugou granite fall in or close to the data range of the ores,
indicating similar sources. In addition, lead isotopic compositions of
the Qiyugou porphyry and the ores resemble those of Huashan
Complex (Tables 6 and 7, Fig. 9), indicating similar sources. Some
geologists suggested that Qiyugou porphyry-breccia and associated
metallogenic system resulted from the fractional crystallization of
Huashan granite (Zhang, 1985; Cui, 1991; Shao, 1992). However, the
following needs to be considered: (1) Qiyugou porphyries are more
basic and were formed at higher temperatures than the Huashan
granites; (2) fractional crystallization of magma usually results in
enrichment of U in the residual magma, leading to the later magmatic
products with higher 206Pb/204Pb and 207Pb/204Pb ratios, which
Fig. 8. Histogram of δ34S values for the Qiyugou Au deposits and hosting lithologies.
contrasts with the Qiyugou porphyries that have lower Pb isotope
ratios than the Huashan granites; (3) If Qiyugou porphyry-breccia and
associated metallogenic system originated from Huashan magma, the
isotopic values of the ores indicates that the sulfur was sourced from a Qiyugou deposit should have similar isotopic compositions with other
magmatic system. deposits surrounding the Huashan granites, but this is not observed
Compared with volcanic rocks of the Xiong'er group (δ34S = 4.1‰), because the isotopic characteristics are different from deposits south of
metamorphic rocks of the Taihua group (δ34S = 3.2‰) and Huashan the Huashan granite, such as the Tieluping silver deposit (Chen et al.,
complex (δ34S = 3.0‰), the ores from Qiyugou tend to have lower 2004, 2005), Shanggong gold deposit (Chen et al., 2006, 2008), Yaogou
δ34S values. Considering that fractionation is caused by variations in gold deposit (Chen and Fu, 1992) and Kangshan gold deposit (Wang
physico-chemical conditions, the discrepancies of δ34S cannot pre- et al., 2001a,b). Therefore, the Qiyugou magma–fluid system is unlikely
clude these geologic bodies as possible sulfur sources. Compared with to be the product of fractional crystallization of Huashan granites.
Fig. 9. Lead isotope diagram (206Pb/204Pb vs. 207Pb/204Pb) for the Qiyugou Au ores and associated lithologies. Based on Zartman and Doe (1981).
Table 8
Isotopic ages of the Qiyugou gold deposit and associated granitoids.
Huashan Wuzhangshan K-feldspar granite Rb–Sr isochron 183 HBGMR, 1989

Huashan Wuzhangshan K-feldspar granite Zircon SHRIMP 156.8 ± 1.2 Li, 2004
Huashan Haoping K-feldspar granite Rb–Sr isochron 123 HBGMR, 1989
Huashan Haoping K-feldspar granite Zircon SHRIMP 130.7 ± 1.4 Li, 2004
Huashan Huashan biotite granite Zircon SHRIMP 132.0 ± 1.6 Li, 2004
Huashan Jinshanmiao K-feldspar granite Rb–Sr isochron 105 HBGMR, 1989
Huashan Whole rock or mineral of granite K–Ar 159, 127, 125 HBGMR, 1989
Heyu Heyu granite Ar/Ar plateau 131.8 ± 0.7 Han et al. (2007a)
Taishanmiao Taishanmiao granite porphyry Ar/Ar plateau ~ 115 Han et al. (2007a)
Wangfangshan Donggou granite porphryr Zircon SHRIMP 112 ± 1 Ye et al. 2006
Wuzhangshan Wuzhangshan granite Ar/Ar 156.0 ± 1.1 Han et al. (2007a)
Qiyugou K-feldspar of ore Ar/Ar plateau 125 ± 3, 124 ± 4 Wang et al., 2001a,b
Qiyugou K-feldspar of ore Ar/Ar plateau 115 ± 2, 122 ± 0.4 Wang et al., 2001a,b
Qiyugou Motianling porphyry K–Ar 125.7 ± 7.2 Ren et al., 2001
Qiyugou Zircon of Qiyugou porphyry U–Pb 119.6 ± 7.5 Ren et al., 2001
Qiyugou Quartz porphyry dyke cutting ore body K–Ar 114.7 ± 1.7 Chen and Fu, 1992
Qiyugou Granodiorite porphyry K–Ar 113 ± 2 Chen and Fu, 1992
Qiyugou Alteration K-feldspar K–Ar 121 ± 2 Chen and Fu, 1992
Qiyugou Pyrite Rb–Sr 126 ± 11 Han et al. (2007b)
The ores have Pb-isotope ratios higher than the Xiong'er Group Qiyugou deposit, yielded two molybdenite Re–Os model ages of 131.6 ±
(Tables 6 and 7, Fig. 9), which indicates that the Xiong'er group cannot 2.0 Ma and 133.1 ± 1.9 Ma, respectively (not shown in Table 8; Li et al.,
be have provided the primary lead sources. The Taihua Supergroup 2006). Other granitoids on the southern margin of the NCC were dated
could have provided lead for the ores, since only two out of 19 ore using the SHRIMP U–Pb zircon method (Mao et al., 2005). The results
samples fall outside the, admittedly poorly defined, Taihua Super- indicate that the Wenyu and Niangniangshan granitic plutons in the
group envelope (Fig. 9). Consequently, the high Pb-isotope ratios of Xiaoqinling region were emplaced at 138.4± 2.5 and 141.7± 2.5 Ma,
the ores indicate that a crustal source with more radiogenic lead respectively, whereas granitic porphyries in the Xiong'ershan region
compositions is probably required. yielded 136.2 ± 1.5 Ma for Leimengou, 158.2 ± 3.1 Ma for Nannihu and
157.6± 2.7 Ma for Shangfanggou (Mao et al., 2005). Han et al. (2007a)
6. Geochronological constraints and ore genesis investigated the evolution of granitic systems in the Xiong'ershan–
Waifangshan region on the basis of Ar–Ar age data, initial 87Sr/86Sr
Selected age data from various sources are shown in Table 8. The ratios and in terms of Ba–Sr geochemistry. These authors concluded that
Haoping pluton of the Huashan granitic complex have zircon SHRIMP the emplacement of granitoids on the southern margin of the NCC
ages of 130.7 ± 1.4 and 132.0± 1.6 Ma, respectively (Li, 2004). The K- occurred in three stages: an early stage of I-type granites at ~157 Ma, a
feldspar of the Qiyugou deposit, formed during potassic metasomatism, middle stage also of I-type granites at ~130 Ma and a final stage
yielded Ar/Ar plateau ages between 125± 3 and 115 ± 2 Ma (Wang characterized by A-type granites at ~115 Ma. According to Han et al.
et al., 2001a,b). The Leimengou porphyry Mo deposit, neighboring the (2007a) the emplacement of these granites in three stages is a
Fig. 10. Breccia pipe model, after Zhang et al. (2007), modified from Kirwin (1985).
Fig. 11. Schematic representation of crust–mantle geodynamic processes (modified after Chen et al., 2007) and associated metallogeny that may have affected the Qinling Orogen and
eastern China, illustrated in four stages, each being an end-member of a time-continuum. In the first stage (A), Triassic collision of the Yangtze and North China cratons,
underthrusting of the Yangtze slab (A-type subduction) with imbricate stacking of crustal slices occur, and are accompanied by uplift, high-P metamorphism. In this stage there is
typically an absence of igneous activity. In the second stage (B), detachment and sinking of the lithospheric mantle and the underthrust continental slab induce upwelling of
asthenospheric mantle, which tends to replace the space created by the sinking lithosphere. In the third stage (C), the tectonic regime is transitional from compression to extensional,
partial melting of the lower crust occurs with the development of I- and A-type granitoids, this is probably the stage at ca. 130 to 135 Ma, when interaction of melts with volatile-rich
lithologies resulted in the emplacement of breccia pipes; during this stage meteoric fluid circulation is enhanced, leading to mixing with deep-sourced fluids and ore deposition
changes from mesothermal to epithermal. The last “snap shot”(D) is characterized by full scale extension, and the eruption of alkali basalts, during this stage more low-T meteoric
fluids may percolate downward. The inset shows a simplified spatial arrangement of the terranes that make up mainland China and the orogens that resulted from their collision,
including the Qinling Orogen (QO), the crustal boundaries and sutures facilitated the access of asthenospheric mantle. JRS Jinshanjan-Red River suture, KL Kunlun terrane, SQL
Southern Qinling terrane, TLF Tanlu Fault, QD Qaidam block, GS Gunahai suture, XS Xiangganzhe suture.
reflection of the geodynamic evolution of the Qinling Orogen. More surface. Exsolution of the aqueous phase during second boiling and
specifically, these stages would represent a tectonic transition from subsequent decompression will cause expansion and the exsolution of
post-collisional to intraplate anorogenic geodynamics in the southern more fluids leading to the formation of breccia pipes (Burnham, 1985).
margin of the North China Craton. Pulses of volatile release and gas streaming will result in the full range
The genesis of breccia pipes and breccia-hosted ores have been of jigsaw breccias and fluidization breccias, where the gas/solid ratios
reviewed by Sillitoe (1985), who listed six possible mechanisms of are very high (McCallum, 1985). Fluidization results in the upward
breccia formation, namely: 1) release of magmatic-hydrothermal transport, mixing and milling of fragments and production of rock
fluids during second boiling; 2) magmatic heating of meteoric pore flour (Sillitoe, 1985; McCallum, 1985). Fig. 10 shows a model of breccia
fluids; 3) interaction of ground waters with magmas causing pipe formed by the degassing of a volatile-rich intrusion. It is possible
phreatomagmatic explosions; 4) eruption from the top part of a that in some cases the development of a pipe does not run to
magma chamber due to sudden decompression, leading to fragmen- completion but may cease due to local exhaustion of volatile
tation of the roof rocks; 5) mechanical disruption of wall rocks during discharge. This may resume at a later stage, but the pipe develops
subsurface movement of melts; 6) tectonic brecciation processes. The along a different channel or pre-existing fracture or fault.
mechanisms of breccia formation in the porphyry-epithermal envir- The age of the Qiyugou alteration minerals and host rocks range
onment is associated with the emplacement of hydrous melts near the from ~125 to ~ 115 Ma; a Rb–Sr dating of pyrite from the No. 4 pipe
yielded an age of 126 ± 11 Ma (Table 8; Han et al., 2007b). The upwelling of asthenospheric mantle, as corroborated by seismic
mineralization includes three stages, an early K-feldspar–quartz– tomography and studies of xenoliths (Griffin et al., 1998; Yuan,
epidote–pyrite, a middle quartz-polymetallic sulfide, and a late 1999; Wilde et al., 2003; Wu et al., 2005). The Mesozoic igneous rocks
quartz–carbonate ± adularia stage. Fluid inclusions include H2O-rich, are accompanied by metamorphic core complexes and basin struc-
CO2-rich, and daughter crystal-bearing. The CO2-rich and daughter tures, indicating crustal uplift and extension. Geochronological
mineral-bearing fluid inclusions are common in the early and middle studies show that this Mesozoic magmatism occurred from the
stages and absent in the late-stage minerals. The early-stage ore-fluids Triassic to Cretaceous, with peaks of activity at 233–210 Ma, 180–
are characteristic of high-temperature (N350 °C), high-salinity 150 Ma and 135–115 Ma. The Triassic to Jurassic magmas were mostly
(N30 wt.% NaCl equiv.), high-fO2, and CO2-rich. The late-stage fluids derived from partial melting of ancient crust, whereas the Cretaceous
are characteristic of low-temperature, low-salinity and CO2-poor. magmas show juvenile signatures, indicating stronger mantle-derived
Boiling possibly resulted in CO2-escape from the fluid-system, and components, leading to alkali basaltic magmatism that continued to
consequently causing rapid precipitation of ore-forming materials and present day (Xu et al., 2005; Yang et al., 2008). These processes of
significant decrease in fO2 and salinity of the ore-fluids from early to fragmentation of lithospheric roots, crustal and lithospheric thinning,
late. Fluid-boiling likely resulted in further hydrothermal brecciation, extension and rifting were probably triggered by the Triassic collision
which connected the fissure-system to the surface, and was followed between the North China Craton and the Yangtze Craton, followed by
by inflow of voluminous meteoric water. Estimated trapping pressures and/or associated with slab break-off of the subducting Pacific
range from 20 to 50 MPa, suggesting that the mineralization occurred (Izanagi) plate (Yang et al., 2008). It is within these evolving
at a depth of about 2 km and resulted from a fluid-system with geodynamic regimes, schematically depicted in Fig. 11, that wide-
alternating lithostatic and hydrostatic pressure controlled by hydrau- spread metallogeny occurred, not only in the Qinling Orogen, but all
lic broken and healing. along major sutures and lithospheric breaks in eastern and north-
The numerous breccia pipes in the Qiyugou area, the proximity of the eastern China.
Leimengou porphyry Mo deposit, together with the common presence
of calcite and fluorite, are indicative of a large scale hydrothermal 7. Conclusions
system that was driven by frequent volatiles exsolution. This would
suggest interaction of magmas with a volatile-rich source. Chen et al. The Qiyugou gold deposits are hosted in breccia pipes that were
(2004) working on the lode deposits of the Xiong'ershan proposed that formed through fluidization processes, similar to those created by
the collision between the Yangtze and North China Cratons that formed experiment in the laboratory and in industry (Zhang et al., 2007). The
the Qinling Orogen, between 240 and 140 Ma, resulted in subduction of Qiyugou pipes were emplaced in metamorphic rocks of the Taihua
a continental plate, crustal thickening and formation of a complex stack Supergroup. Carbon, hydrogen, oxygen, sulfur and lead isotope
of north-verging thrust slabs. This underthrusting or A-type subduction geochemistry indicates that the ore fluids were sourced from
was accompanied by metamorphic devolatilization of sedimentary magmatic water in early stage and evolved to meteoric water in late
rocks that included carbonate–shale–chert successions of the Guan- stage, and ore-forming elements were sourced from magma–fluid
daokou and Luanchan Groups, south of the Maochaoying fault (Fig. 1). system mostly contributed by metamorphic devolatilization of an
Northward underthrusting, crustal shortening and thickening was underthrust continental slab. The Qiyugou breccia-pipes and their
followed by extensional collapse and the emplacement of granitic associated gold ores were emplaced during an extensional regime
magmas during the late Cretaceous phase of the Yanshanian tecto- following a transition from collision to rifting tectonics. The Qiyugou
nothermal events, as elaborated below. Based on robust isotopic and gold deposits are intrusion-related explosive breccia pipe-type.
fluid inclusions evidence, Chen et al. (2004) further proposed that
metallogeny in the east Qinling area which, as previously mentioned, Acknowledgments
comprises precious metal lodes, porphyry and the breccia pipes
discussed in this paper, exhibit a zoning from the Maochaoying fault This work was financially supported by the National 973-program
in the southwest to the northeast, from orogenic lodes to porphyry to (Project 2006CB403508), the NSFC (Grant Nos. 40425006, 40730421,
the Qiyugou breccia pipes, respectively. 40352003) and Hundred Young Scientists Program of CAS. Franco
During the extensional collapse referred to above, we argue that Pirajno publishes with the permission of the Executive Director of the
the magmas interacted with the volatile-rich sedimentary rocks Geological Survey of Western Australia.
thereby resulting in the emplacement of high level plutons from
which a range of porphyry and intrusion-related ore systems
References
developed between ~130 and ~ 115 Ma. From fluid inclusion data we
suggest that the Qiyugou deposits may have first formed in a Bodnar, R.J., 1993. Revised equation and stable for determining the freezing point
hypothermal regime that subsequently evolved through mesothermal depression of H2O–NaCl solutions. Geochimica et Cosmochimica Acta 57, 683–684.
to epithermal. As such, the Qiyugou breccia pipe gold deposits may be Bryant, D.L., Ayers, J.C., Gao, S., Miller, C.F., Zhang, H.-F., 2004. Geochemical, age and isotopic
constraints on the location of the Sino-Korean/Yangtze suture and evolution of the
considered as an intrusion-related ore system (Lang et al., 2000; Lang Northern Dabie Complex, east central China. GSA Bulletin 116, 698–717.
and Baker, 2001). Burnham, C.W., 1985. Energy release in subvolcanic environments: Implications for
The volatile-rich nature of the hydrothermal fluids was conducive breccia formation. Economic Geology 80, 1515–1522.
Chen, W., 1995. Lead isotope study of gold and silver (lead) deposits in Xiong'er Shan,
to the formation of the numerous breccia pipes in the region. The western Henan. Geology of Precious Metals 4, 168–176 (in Chinese with English
weakly negative δ34S values for the Qiyugou sulfides could be derived abstract).
from a “memory” of a sedimentary source, as postulated for similar Chen, Y.J., Fu, S.G., 1992. Gold Mineralization in West Henan. Seismological Press,
Beijing. 234 pp. (in Chinese with English abstract).
values obtained from the orogenic lodes in the region (Chen et al., Chen, Y.J., Fu, S.G., Qiang, L.Z., 1992. The tectonic environment for the formation of the
2004). The sub-horizontal (least compressive stress σ3 perpendicular Xiong'er Group and the Xiyanghe Group. Geological Review 38, 325–333 (in Chinese).
to the palaeosurface?) sheeted ore zones within the pipes are difficult Chen, Y.J., Li, C., Zhang, J., Li, Z., Wang, H.H., 2000. Sr and O isotopic characteristics of
porphyries in the Qinling molybdenum deposit belt and their implication to genetic
to explain in our present state of knowledge. It is possible that heated
mechanism and type. Science in China. Series D 43 (Suppl.), 82–94.
groundwater flow circulated in the pipe causing the redistribution of Chen, Y.J., Pirajno, F., Sui, Y.H., 2004. Isotope geochemistry of the Tieluping silver
ore minerals and gold in shears or fractures that were formed during deposit, Henan, China: a case study of orogenic silver deposits and related tectonic
the solidification of the breccia pipes. setting. Mineralium Deposita 39, 560–575.
Chen, Y.J., Pirajno, F., Sui, Y.H., 2005. Geology and D–O–C isotope systematics of the
The widespread Mesozoic magmatism of eastern China has been Tieluping silver deposit, Henan, China: implications for ore genesis. Acta Geologica
attributed to removal of subcontinental mantle lithosphere and Sinica (English edition) 79, 106–119.
Chen, Y.J., Pirajno, F., Qi, J.P., Li, J., Wang, H.H., 2006. Ore geology, fluid geochemistry and Luo, M.J., Li, S.M., Lu, X.X., Su, Z.B., 2000. Metallogenesis and Deposit Series of Main
genesis of the Shanggong gold deposit, eastern Qinling Orogen, China. Resource Minerals Resources of Henan Province. Geological Publishing House, Beijing. 452 pp.
Geology 56, 99–116. (in Chinese).
Chen, Y.J., Chen, H.Y., Zaw, K., Pirajno, F., Zhang, Z.J., 2007. Geodynamic settings and Mao, J.W., Goldfarb, R.J., Zhang, Z.W., 2002. Gold deposits in the Xiaoqingling–
tectonic model of skarn gold deposits in China: an overview. Ore Geology Reviews Xiong'ershan region, Qinling Mountains, central China. Mineralium Deposita 37,
31, 139–169. 306–325.
Chen, Y.J., Pirajno, F., Qi, J.P., 2008. The Shanggong gold deposit, Eastern Qinling Orogen, Mao, J.W., Xie, G.Q., Zhang, Z.H., Li, X.F., Wang, Y.T., Zhang, C.Q., Li, Y.F., 2005. Mesozoic
China: isotope geochemistry and implications for ore genesis. Journal of Asian Earth large-scale metallogenic pulses in North China and corresponding geodynamic
Sciences 33, 252–266. setting. Acta Petrologica Sinica 21 (1), 169–188 (in Chinese with English abstract).
Clayton, R.N., O' Neil, J.R., Mayeda, T.K., 1972. Oxygen isotope exchange between quartz Mao, J.W., Xie, G.Q., Bierlein, F., Qü, W.J., Du, A.D., Ye, H.S., Pirajno, F., Li, H.M., Guo, B.J., Li,
and water. Journal of Geophysical Research B77, 3057–3067. Y.F., Yang, Z.Q., 2008. Tectonic implications from Re–Os dating of Mesozoic
Cui, B., 1991. Lead isotope compositions of non-ferrous and precious metallic deposits at molybdenum deposits in the East Qinling–Dabie orogenic belt. Geochimica et
the southern margin of the North China Platform. Mineral Deposit Exploration (2), Cosmochimica Acta 72, 4607–4626.
30–41 (in Chinese). McCallum, M.E., 1985. Fluidization processes in breccia formation. Economic Geology
Fan, H.R., Xie, Y.H., Zhao, R., Wang, Y.L., 1994. Stable isotope geochemistry of rocks and 80, 1523–1543.
gold deposits in Xion'ershan area, Western Henan. Collections of Geology and Meng, Q.-R., Zhang, G.-W., 2000. Geologic framework and tectonic evolution of the
Exploration 9, 54–64 (in Chinese with English abstract). Qinling orogen, central China. Tectonophysics 323, 183–196.
Fan, H.R., Xie, Y.H., Zheng, X.Z., Wang, Y.L., 2000. Ore-forming fluids in hydrothermal O'Neil, J.R., Clayton, R.N., Mayada, T.K., 1969. Oxygen isotope fractionation in divalent
breccia-related gold mineralization in Qiyugou, Henan Province. Acta Petrologica metal carbonates. Journal of Chemical Physics 51, 5547–5558.
Sinica 16, 559–563 (in Chinese with English abstract). Peng, P., Zai, M.G., Zhang, H.F., Guo, J.H., 2005. Geochronological constraints on the
Faure, G., 1986. Principles of Isotope Geology, 2nd edition. John Wiley and Sons, New Paleoproterozoic evolution of the North China Craton: SHRIMP zircon ages of
York. 589 pp. different types of mafic dikes. International Geology Review 47, 492–508.
Gao, Y.F., Luan, W.L., Wei, R.H., 1994. Stable isotope study of the Qiyugou gold deposits. Peng, P., Zhai, M.G., Ernst, R.E., Guo, J.G., Liu, F., Hu, B., 2008. A 1.78 Ga large igneous
Mineral Deposits 13, 354–361 (in Chinese with English abstract). province in the North China Craton: the Xiong'er Volcanic Province and the North
Gao, Y.F., Luan, W.L., Wei, R.H., Li, Y.S.,1995. Fluid inclusion studies of Qiyugou gold deposits, China Dyke Swarm. Lithos 101, 260–280.
Henan. Geochimica 24 (Suppl.), 150–159 (in Chinese with English abstract). Qi, J.Z., Ma, Z.R., Li, L., 2004. Fluid evolution of Qiyugou cryptoexplosive-breccia
Gernet, J., 1999. A History of Chinese Civilization. Cambridge University Press, type gold deposit, Henan. Gold Geology 10 (4), 1–10 (in Chinese with English
Cambridge, U.K. 801 pp. abstract).
Guo, D.S., Chen, Y.J., Qi, J.P., 2007. Isotope geochemistry and ore genesis of the Qiyugou Qi, J.P., Zhang, J., Tang, G.J., 2005. Carbon and oxygen isotope composition of the Meso-
gold deposit, Henan: a synthesis. Geological Review 53, 217–228 (in Chinese with Neoproterozoic strata south of the Xiong'er Terrane: evidences of the CMF model.
English abstract). Acta Petrologica Sinica 21, 1365–1372 (in Chinese with English abstract).
Griffin, W.L., Andi, Z., O'Reilly, S.Y., Ryan, C.G., 1998. Phanerozoic evolution of the Ratschbacher, L., Hacker, B.R., Calvert, A., Webb, L.E., Grimmer, J.C., McWilliams, M.O.,
lithosphere beneath the Sino-Korean Craton. In: Flower, M., Chung, S.L., Lo, C.-H., Ireland, T., Dong, S., Hu, J., 2003. Tectonics of the Qinling (Central China):
Lee, T.-Y. (Eds.), Mantle Dynamics and Plate Interactions in East Asia. Geodynamic tectonostratigraphy, geochronology and deformation history. Tectonophysics 366,
Series, vol. 27. American Geophysical Union, pp. 107–126. 1–53.
Han, Y.-G., Zhang, S.-H., Pirajno, F., Zhang, Y.-H., 2007a. Evolution of the Mesozoic Ren, F.G., Yin, Y.J., Li, S.B., 2001. Isotope geochronology as evidence of the Indosinian
granites in the Xiong'ershan–Waifangshan region, western Henan province, China, metallogenesis in the Xiong'er Rift. Bulletin of Mineralogy, Petrology and
and its tectonic implications. Acta Geologica Sinica 81, 253–265. Geochemistry 20, 286–288 (in Chinese with English abstract).
Han, Y.-G., Zhang, S.-H., Zhang, Y.-H., Chen, F.-K., 2007b. Single grain Rb–Sr dating of Schidlowski, M., 1998. Beginning of terrestrial life: problems of the early record and
euhedral and cataclastic pyrite from the Qiyugou gold deposit in western Henan, implications for extraterrestrial scenarios. Instruments, methods, and missions for
central China. Chinese Science Bulletin 52, 1820–1826. astrobiology. SPIE 3441, 149–157.
HBGMR (Henan Bureau of Geology and Mineral Resources), 1989. Regional Geology of Schwartz, M.O., 1989. Determining phase volumes of missed CO2–H2O inclusions using
Henan Province. China Geological Publishing House, Beijing. 772 pp. (in Chinese microthermometric measurements. Mineralium Deposita 24, 43–47.
with English abstract). Seedorff, E., Dilles, J.H., Proffett, J.M., Einaudi, M.T., Zurcher, L., Stavast, W.J.A., Johnson, D.A.,
He, Y.H., Zhao, G.C., Sun, M., Wilde, S.A., 2007. Geochemistry, isotope systematics and Barton, M.D., 2005. Porphyry deposits: characteristics and origin of hypogene features.
petrogenesis of the volcanic rocks in the Zhongtiao Mountain: an alternative Economic Geology 100th Anniversary Volume, pp. 251–298.
interpretation for the evolution of the southern margin of the North China Craton. Shao, K.Z., 1992. Characteristics of Qiyugou gold deposits and their prospecting
Lithos 102, 158–178. perspective geological setting. Journal of Hebei College of Geology 15, 105–195
Hoefs, J., 1997. Stable Isotope Geochemistry, 4th edition. Springer-Verlag, Berlin. 201pp. (in Chinese with English abstract).
Hou, G.-T., Santosh, M., Qian, X.-L., Lister, G.S., Li, J.-H., 2008. Configuration of the late Shao, K.Z., Li, S.R., 1989. Significance of quartz thermoluminescence in the study of
Palaeoproterozoic supercontinent Columbia: insights from radiating mafic dyke Qiyugou (type) gold deposits. Journal of Hebei College of Geology 12 (2), 127–133
swarms. Gondwana Research. doi:10.1016/j/gr.2008.01.010. (in Chinese with English abstract).
Hu, S.-X. (Ed.), 1988. Geology and Metallogeny of the Collision Belt Between the North Sillitoe, R.H., 1985. Ore-related breccias in volcanoplutonic arcs. Economic Geology 80,
and the South China Plates. Nanjing University Press, Nanjing. 558 pp. (in Chinese). 1467–1514.
Jin, W., Liu, F., 1994. Isotopic compositions of S, O, C and Pb of the Qiyugou gold deposit Tang, R., 1988. Study of the ore-forming conditions of gold deposits in the Qiyugou area,
and their implications to the source of ore-forming materials. Modern Geology 8, Songxian county, Henan province. Henan Bureau of Geological Exploration of Non-
139–145 (in Chinese). ferrous Metals, Zhengzhou, Unpublished report. (in Chinese).
Kerrich, R., Goldfarb, R., Groves, D., Garwin, S., Jia, Y.F., 2000. The characteristics, origins Wang, B.D., Li, S.R., 1996. Geology and geochemical features of the Qiyugou explosive
and geodynamic settings of supergiant gold metallogenic provinces. Science in breccia type gold deposits, Henan Province. Geology-Geochemistry 6, 37–44
China. Series D 43 (suppl.), 1–68. (in Chinese).
Kirwin, D.J. 1985. Tourmaline breccia pipes. Unpublished Msc Thesis, James Cook Wang, Z.G., Cui, B., Xu, M.L., 1997. Tectonic Evolution and Mineralization of the Southern
University, North Queensland, 139 pp. Margin of the North China Block. China Metallurgical Industry Press, Beijing. 310 pp.
Lang, J.R., Baker, T., 2001. Intrusion-related gold systems: the present level of (in Chinese).
understanding. Mineralium Deposita 36, 477–489. Wang, H.H., Chen, Y.J., Gao, X.L., 2001a. The isotope geochemistry of the Kangshan gold
Lang, J.R., Baker, T., Hart, C.J.R., Mortensen, J.K., 2000. An exploration model for deposit, Henan and its illustration of the CPMF model. Mineral Deposits 20,
intrusion-related gold systems. SEG Newsletter 40, 1–15. 190–198 (in Chinese with English abstract).
Li, Y.F., 2004. Study of the large-scale hydrothermal ore-forming gold systems in Wang, Y.T., Mao, J.W., Lu, X.X., 2001b. 40Ar/39Ar dating and geochronological constraints
Xiaoqinling–Xiong'ershan area. Unpublished report of state key project (973), 57 pp. on the ore-forming epoch of the Qiyugou deposit in Songxian County, Henan
(in Chinese). Province. Geology Reviews 47, 551–555 (in Chinese with English Abstract).
Li, Y.F., 2005. The temporal-spatial evolution of Mesozoic granitoids in Xiong'ershan White, N.C., 2003. Epithermal gold deposits. Society of Economic Geologists Beijing
area and their relationships to molybdenite–gold mineralization. Unpublished Ph. Gold Workshop, October 25–26, 2003. 118 pp. (Confidential document distributed
D. thesis, China University of Geosciences, Beijing, 135 pp. (in Chinese). in China University of Geosciences).
Li, Y., Ren, C.S., 1990. Lead isotope evolution of the southern margin of North China Wilde, S.A., Zhou, X.-H., Nemchin, A.A., Sun, M., 2003. Mesozoic crust–mantle
Platform. Journal of Xi'an College of Geology 13 (2), 1–12 (in Chinese with English interaction beneath the North China Craton: a consequence of the dispersal of
abstract). Gondwanaland and accretion of Asia. Geology 31, 817–820.
Li, Y.F., Mao, J.W., Liu, D.Y., Wang, Y.B., Wang, Z.L., Wang, Y.T., Li, X.F., Zhang, Z.H., Guo, B.J., William-Jones, A.E., Heinrich, C.A., 2005. Vapor transport of metals and the formation of
2006. SHRIMP zircon U–Pb and molybdenite Re–Os dating for the Leimengou magmatic–hydrothermal ore deposits. Economic Geology 100, 1287–1312.
prophyry molybdenum deposit, Western Henan and its geological implication. Wu, H.C., Zhang, S.H., Li, Z.X., Li, H.Y., Dong, J., 2005. New paleomagnetic results from the
Geological Review 52 (1), 122–131 (in Chinese with English abstract). Yangzhuang Formation of the Jixian System, North China, and tectonic implications.
Luo, M.J. (Ed.), 1992. Introduction to Gold Deposits in Henan Province. Beijing: China Chinese Science Bulletin 50, 1483–1489.
Seismological Press, Beijing. 312 pp. (in Chinese). Xie, Y.H., Fan, H.R., Li, R.M., Wang, Y.L., 1991. Fluid inclusion studies of Qiyugou
Luo, Z.K., Guan, K., 1995. Study of the geology, geochemistry and ore genesis of the exploration breccia-type gold deposit, Henan. Acta Mineralogica Sinica 11 (4),
Qiyugou gold deposit, Henan province. Geology of Precious Metals 4 (1), 1–12 370–376 (in Chinese).
(in Chinese). Xu, Y.G., Ma, J.L., Frey, F.A., Feigenson, M.D., Liu, J.-F., 2005. Role of lithosphere–
Luo, M.J., Zhang, F.M., Dong, Q.Y., Xu, Y.R., Li, S.M., Li, K.H., 1991. China Molybdenite astenosphere interaction in the genesis of Quaternary alkali and tholeiitic basalts
Deposits. Henan Scientific technology Press, Zhengzhou. 355 pp. (in Chinese). from Datong, western North China Craton. Chemical Geology 224, 247–271.
Yang, J.H., Wu, F.Y., Wilde, S.A., 2003. A review of the geodynamic setting of large scale Zhang, Y.-H., Zhang, S.-H., Han, Y.-G., Pirajno, F., 2005. Low-sulphidation epithermal
Late Mesozoic gold mineralization in the North China Craton: an association with gold-bearing Qiyugou breccia pipes, Xiong'ershan mountains, China. In: Mao, J.W.,
lithospheric thinning. Ore Geology Reviews 23, 125–152. Bierlein, F.P. (Eds.), Mineral Deposit Research: Meeting the Global Challenge, vol. 2.
Yang, J.H., Wu, F.Y., Wilde, S.A., Belousova, E., Griffin, W.L., 2008. Mesozoic decratoniza- Springer, Berlin, pp. 1111–1113.
tion of the North China block. Geology 36, 467–470. Zhang, Y.-H., Zhang, S.-H., Pirajno, F., 2007. Fluidization: an important process in the
Ye, H.S., Mao, J.W., Li, Y.F., Guo, B.J., Zhang, C.Q., Liu, J., Yan, Q.R., Liu, G.Y., 2006. SHRIMP formation of the Qiyugou Au-bearing breccia pipes in Central China. Acta Geologica
zircon U-Pb and molybdenite Re-Os dating for the superlarge Donggou porphyry Sinica 81, 226–238.
Mo deposit in East Qinling, China and its geological implication. Acta Geologica Zhao, T.P., 2000. The characteristics and genesis of the high-K volcanic rocks within the
Sinica 80, 1078–1088. Proterozoic Xiong'er Group at the southern margin of the North China block. Ph.D.
Yuan, X.C., 1999. Velocity structure of the Qinling lithosphere and mushroom cloud thesis, Institute of Geology and Geophysics, Chinese Academy of Sciences, 102 pp.
model. Science in China. Series D, Earth Sciences 39, 235–244. (in Chinese with English abstract).
Zartman, R.E., Doe, B.R., 1981. Plumbotectonics—the model. Tectonophysics 75, 135–162. Zhao, T.P., Zhou, M.F., Zhai, M., Xia, B., 2002. Paleoproterozoic rift-related volcanism of
Zhang, Y.S., 1985. Research Report of the genetic types and metallogenic conditions of the Xiong'er Group, North China Craton: implications for the breakup of Columbia.
the gold deposits in Henan province. Henan Institute of Geology, Zhengzhou, International Geology Reviews 44, 336–351.
unpublished. (in Chinese). Zhao, G.C., Sun, M., Wilde, S.A., Li, S.Z., 2004. A Paleo-Mesoproterozoic supercontinent:
Zhang, Y.H., 2006. The Qiyugou auriferous breccia pipes: an adularia-sericite epithermal assembly, growth and breakup. Earth-Science Reviews 67, 91–123.
system, associated with porphyry Mo in the Xiong'ershan, Henan Province, China.
Unpublished Ph.D. thesis, China University of Geosciences, Beijing.
Zhang, G.W., Xiang, L.W., Meng, Q.R., 1995. The Qinling Orogen and intracontinental
orogen mechanism. Episodes 18, 36–39.

Isotope Systematics and Fluid Inclusion

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Ore Geology Reviews 35 (2009) 245–261

Contents lists available at ScienceDirect

Ore Geology Reviews

Notation: clm, clathrate melting; dmd, daughter mineral dissolution.

3. Mineralisation and hydrothermal alteration

The mineralization styles include vein, disseminations and stock-

Note: salinity is expressed in wt.% NaCl. equiv.

No. Sample Mineral δ18OM δ18OW T/°C δD δ13CPDB Stage Reference

No. Sample description Mineral δ34S Reference

5.1. Hydrogen and oxygen 5.2. Carbon

Shanggong gold deposit (δ34S = −14.6–6.3‰; Chen et al., 2006,

The ores have lead isotope ratios of 206Pb/204Pb from 16.771 to

Huashan Wuzhangshan K-feldspar granite Rb–Sr isochron 183 HBGMR, 1989

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