Formation of porphyry Mo deposit in a deep fault zone, example from the Dabaoshan porphyry Mo deposit in northern Guangdong, South China

    Formation of porphyry Mo deposit in a deep fault zone, example from the Dabaoshan porphyry Mo deposit in northern Guangdong, South China Wenting Huang, Hua-ying Liang, Jing Wu, Yin-qiao Zou, Jian Zhang PII: DOI: Reference:

S0169-1368(16)30436-X doi: 10.1016/j.oregeorev.2016.07.013 OREGEO 1877

To appear in:

Ore Geology Reviews

Received date: Revised date: Accepted date:

27 September 2015 18 July 2016 20 July 2016

Please cite this article as: Huang, Wenting, Liang, Hua-ying, Wu, Jing, Zou, Yin-qiao, Zhang, Jian, Formation of porphyry Mo deposit in a deep fault zone, example from the Dabaoshan porphyry Mo deposit in northern Guangdong, South China, Ore Geology Reviews (2016), doi: 10.1016/j.oregeorev.2016.07.013

This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

ACCEPTED MANUSCRIPT Formation of porphyry Mo deposit in a deep fault zone, example from the

IP

T

Dabaoshan porphyry Mo deposit in northern Guangdong, South China

a

SC R

Wenting Huanga, Hua-ying Lianga*, Jing Wub, c, Yin-qiao Zoua, c, Jian Zhang a, c，

Key Laboratory of Mineralogy and Metallogeny, Guangzhou Institute of Geochemistry,

NU

Chinese Academy of Sciences, 511 Kehua Street, Wushan, Guangzhou 510640, China b

MA

College of Resources and Metallurgy, Guangxi University, Nanning, Guangxi 530004,

China

University of Chinese Academy of Sciences, Beijing 100049, China;

TE

D

c

CE P

First author: Wenting Huang

AC

Key Laboratory of Mineralogy and Metallogeny, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, 511 Kehua Street, Wushan, Guangzhou 510640, China Tel: 86-20-85290107 E-mail: [email protected] Corresponding author: Hua-ying Liang Key Laboratory of Mineralogy and Metallogeny, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, 511 Kehua Street, Wushan, Guangzhou 510640, China Tel: 86-20-85290107

ACCEPTED MANUSCRIPT E-mail: [email protected] Names and addresses of co-authors:

IP

T

Jing Wu

SC R

College of Resource and Metallurgy, Guangxi University, Nanning, Guangxi 530004, China, E-mail: [email protected] Yin-qiao Zou

NU

Key Laboratory of Mineralogy and Metallogeny, Guangzhou Institute of Geochemistry,

MA

Guangzhou 510640, China, E-mail: [email protected] Jian Zhang

D

Key Laboratory of Mineralogy and Metallogeny, Guangzhou Institute of Geochemistry,

AC

CE P

TE

Guangzhou 510640, China, E-mail: [email protected]

ACCEPTED MANUSCRIPT Abstract The Dabaoshan porphyry Mo deposit is located in the Wuchuan-Sihui fault zone, a deep

IP

T

fault system in South China. The Dabaoshan Mo mineralization occurs as disseminations and

SC R

veinlets in the Dabaoshan porphyries and skarn-greisen associated with the Chuandu porphyritic monzogranite. Here we report the zircon LA-ICP-MS U-Pb ages of the porphyries mentioned above. We also present the major and trace elements, whole-rock Sr-Nd and the

NU

zircon Hf isotopic compositions of the Dabaoshan porphyries. The Dabaoshan porphyries are

MA

composed of weakly to strongly peraluminous monzogranite porphyry and granite porphyry. They yield ages of 166.3±2.0 Ma (MSWD=1.9) and 166.2±2.7 Ma (MSWD=2.7),

D

respectively, slightly older than the Chuandu porphyritic monzogranite pluton which

TE

crystallized at 162.1±1.6 Ma (MSWD=2.7). This is indicative of two distinct magmatic pulses

CE P

in this region. The Dabaoshan porphyries have 64.42%-75.41% SiO2 and show an affinity of high-K calc-alkaline and shoshonite in the plot of Th vs. Co. They have [La/Yb]N of 14.6 -

AC

35.0 and Ɛ Nd(t) values ranging from -8.2 to -6.6. The Ɛ Nd(t) values of the rocks are more negative than those for the Middle Jurassic mafic rocks (Ɛ Nd(t)= -2.7 to +7.9) in the region, but similar to those for Proterozoic crust in the Cathaysia Block at ~165 Ma. Zircon from the Dabaoshan porphyries have Ɛ Hf(t) values ranging from -13.2 to -7.5 and two-stages Hf model ages (TDM2) from 1.7 to 2.0 Ga, close to the TDM2 (~1.7 Ga) of the basement in the western Cathaysia Block. The Dabaoshan porphyries have averaged Th/U of 5.0, similar to those for the Proterozoic crystalline basement (Th/U = 5.3 - 5.4) in the Cathaysia Block, but higher than those for arc magmas (Th/U = 1.5 - 3.0). Moreover, Nb/Ta ratios of the porphyries (average 11.8) are also similar to those of the Cathaysia Protorozoic crystalline basement

ACCEPTED MANUSCRIPT (average 12.4). These geochemical features indicate that the porphyries were derived from high-degree partial melting of the crystalline basement in the Cathaysia Block. Based on the

IP

T

available geochemical data of the Dabaoshan porphyries, together with that of porphyry Mo

SC R

deposits distributed along the Wuchuan-Sihui deep fault zone, it is concluded that the Dabaoshan porphyry Mo deposit is genetically related to the movements of the Wuchuan-Sihui deep fault induced by the subduction of the paleo-Pacific plate during the

NU

Jurassic.

MA

Keywords: Porphyry Mo deposit; Deep fault characteristics; the Dabaoshan; northern Guangdong province;

D

1 Introduction

TE

Porphyry deposits worldwide commonly occur in convergent margins, either in

CE P

subduction environments associated with subduction-derived calc-alkaline felsic magmas (Camus and Dilles, 2001; Mitchell, 1973; Sillitoe, 1972; Sun et al., 2015; Sun et al., 2010), or

AC

continental collision-subduction environment related to high-K calc-alkaline and shoshonitic magmas (Chen, 2002; 2013; Chen et al., 2000; Chen and Li, 2009; Hou et al., 2015; Hou et al., 2013b; Liang et al., 2006; Liang et al., 2009; Richards, 2009b). Porphyry copper deposits in subduction environments have been extensively studied for a few decades (Camus and Dilles, 2001; Cooke et al., 2005; Richards, 2003; Sillitoe, 1972; 2010; Sun et al., 2015; Sun et al., 2010) but there are porphyry deposits in continental collision zones (Chen, 2013; Chen et al., 2016; Hou et al., 2009; Richards, 2009a). It is thought that subduction-related arc magmas are formed by the partial melting of metasomatized mantle wedge (Richards, 2003) while collision-related fertile magmas are derived from remelting of thickened juvenile lower crust

ACCEPTED MANUSCRIPT (Hou et al., 2009; Richards, 2009a). Neither model explains the occurrence of porphyry Cu (Mo) deposits occur in the interior of the South China Block (SCB) (Zhong et al., 2016),

IP

T

several hundred kilometers away from the subduction zones. Explanations for the SCB

SC R

porphyries included partial melting of juvenile lower crust in an intracontinental setting (Hou et al., 2013a; Wang et al., 2006), or slab melting related to flat subduction (Sun et al., 2012; Zhang et al., 2013).

NU

The Dabaoshan porphyry Mo deposit is a newly discovered porphyry deposit in northern

MA

Guangdong, interior of the SCB. Models for its petrogenesis depends on knowing the crystallization age of the system (Chen et al., 2012; Li et al., 2012; Wang et al., 2011b; Zhong

D

et al., 2010). Wang et al. (2011) suggested that the Dabaoshan porphyry and the adjacent

TE

Chuandu porphyritic intrusion were emplaced at about 175 Ma during a post-collisional

CE P

lithosphere extension. On the other hand, Li et al. (2012) proposed that the magma of the Dabaoshan porphyries was emplaced at about 166 Ma, which was induced by slab rollback of

AC

the obliquely subducted paleo-Pacific plate. Zhang et al. (2013) considered that the porphyry deposits in northern Guangdong are related to the westward subduction of the Paleo-Pacific plate.

The Dabaoshan porphyry Mo deposit is located in the Wuchuan-Sihui deep fault zone in northern Guangdong (GDGBMR, 1985). It is suggested that the Wuchuan-Sihui deep fault zone is a zone rich in porphyry Mo mineralization, as three porphyry Mo deposits have been found recently along this fault zone (Xu, 2013). This close geographical proximity implies a close relationship between the presence of the fault and the porphyry Mo mineralization. Moreover, the locality of the Dabaoshan porphyry Mo deposit is more than 1500 km away

ACCEPTED MANUSCRIPT from the present-day northeastward Pacific-oceanic trench. It is believed that the paleo-Pacific plate was subducted southwestward from the Early Jurassic to Early Cenozoic

IP

T

and then northwestward after the Early Cenozoic (Sun et al., 2007). Thus, the subduction zone

SC R

in the Jurassic should have been even more distant from the Dabaoshan porphyry Mo deposit than the present-day oceanic trench. This means that a petrogenetic association with a concurrent subduction zone is nearly impossible. The Dabaoshan porphyry Mo deposit is a

NU

rare type formed in an intracontinental setting.

MA

This work presents a geochronology and geochemistry of the intrusions in the Dabaoshan district and addresses the metallogenesis and geodynamic setting of the Dabaoshan porphyry

2 Geological Setting

TE

D

Mo deposit.

CE P

The Dabaoshan porphyry Mo orebodies contain over 90% resources of the deposit, and the Chuandu skarn-greisen Mo orebodies the remaining 10% (Fig. 1). The porphyry system

AC

contains 0.25 Mt Mo at grades of 0.06-0.11% and 0.06 Mt WO3 at grades of 0.07-0.30%. The Dabaoshan porphyry Mo deposit, specifically, is the largest porphyry Mo deposit so far discovered in the district. The South China Block consists of the Yangtze block in the northwest and the Cathaysia Block in the southeast (Chen and Jahn, 1998) (Fig. 1). The Yangtze and Cathaysia blocks have Archean (Qu et al., 2007, Xu et al., 2016) and Early Proterozoic crystalline basements (Chen and Jahn, 1998), respectively. The Yangtze Block collided with the Cathaysia Block in the Neoproterozoic (Li and McCulloch, 1996) near what is now the Shi-Hang rift zone (Gilder et al., 1991; Goodell et al., 1991), and this amalgamation along a lithosphere thick

ACCEPTED MANUSCRIPT suture resulted in the formation of the coherent SCB during the Phanerozoic. Several porphyry deposits have been found along the Shi-Hang rift zone (Fig. 1), which is now

IP

T

considered a porphyry ore-rich zone. The Wuchuan-Sihui fault is a major deep fault that

SC R

initiated in the early Ordovician with a strike of NE 35 - 45 and a length of >800km in Guangdong and Jiangxi provinces (GDGBMR, 1985). The Wuchuan-Sihui deep fault zone is characterized by denudation along a 1~20km-wide belt of migmatite and mylonite. The

NU

Wuchuan-Sihui fault cuts through the lithosphere (GDGBMR, 1985), which is evidenced by

MA

the Nanhu PGE mineralized ultramafic igneous rocks derived from mantle occurring at the southern part of the deep fault zone (Fig. 1) (GDGBMR, 1985), the strong Bouguer

D

gravitational anomalies, and the Moho deep variation across the Wuchuan-Sihui fault zone

TE

(GDGBMR, 1985; Zheng, 1996). More detailed information on the structure, geology, and

CE P

lithologies of the Wuchuan-Sihui deep fault zone is given by Zhen (1996), Huang and Zheng (2001) and Wang et al. (2001). Two large and one medium-sized porphyry Mo deposits have

AC

been found in the Wuchuan-Sihui fault zone (Fig. 1, Xu, 2013), of which the Dabaoshan porphyry Mo deposit is the largest one. The Dabaoshan porphyry Mo deposit was discovered in the northwestern part of the Dabaoshan polymetallic (Cu-Pb-Zn-Fe) ore field in 2006. It is located about 40 km north of Shaoguan

City,

Guangdong

province.

The

Dabaoshan

polymetallic

Cu-Pb-Zn-Fe

mineralization occurs as stratiform orebodies associated with Silurian volcanic rocks (zircon U-Pb ages of 436.4±4.1Ma to 434.1±4.4Ma, Wu et al., 2014). The Dabaoshan porphyries, with an outcrop area of 0.18 km2, intruded carbonaceous shale and quartz sandstone and the Silurian volcanics (Fig. 2a) (Wu et al., 2014). These rocks display porphyritic textures (Fig.2b,

ACCEPTED MANUSCRIPT c), with K-feldspar, plagioclase, quartz, muscovite and biotite phenocrysts set in a fine-sized phanerocrystalline matrix of similar mineralogical assemblage (Fig. 2b, c). The Dabaoshan

IP

T

porphyries are composed of monzogranite and granite porphyry. The Dabaoshan porphyry Mo

SC R

deposit consists of veinlets and disseminated ores hosted in the porphyries (Fig. 2d, e) and adjacent Silurian volcanic rocks. The ore minerals include molybdenite, pyrite, scheelite and wolframite, with minor chalcopyrite and bismuthinite. The gangue minerals include quartz,

NU

feldspar, mica, calcite, clay minerals and minor fluorite. The Dabaoshan porphyries

MA

underwent strong hydrothermal alteration. Four alteration stages are recognized: 1. an early potassic alteration stage, which is characterized by the formation of secondary muscovite and

D

quartz or K-feldspar and quartz associated with pyrite, some molybdenite and minor

TE

magnetite; 2. a quartz-sericite alteration stage, which is characterized by the replacement of

CE P

fine grained quartz and sericite, together with abundant quartz-sulfide (molybdenite + pyrite) veinlets; 3. a propylitic alteration stage characterized by the formation of carbonate minerals,

AC

pyrite and chlorite; 4. and an argillic alteration stage characterized by the formation of clay minerals and hydromica. The Chuandu pluton consists mainly of porphyritic monzogranite with minor porphyritic granite. It intruded Silurian volcanics, Cambrian sandstone-slate and Devonian limestone and sandstone with an outcrop area of 0.7 km2 (Fig. 1). The Chuandu rocks show porphyritic texture, with coarse-grained (>3mm) phenocrysts of plagioclase, K-feldspar, quartz and muscovite set in a medium grained (1-2 mm) phanerocrystalline matrix of similar mineralogical assemblage (Fig. 2f). It is altered in the form of potassic-silica alteration (Fig. 2f), greisenization, quartz-sericite and argillic alteration. The Mo mineralization occurs

ACCEPTED MANUSCRIPT mainly in the skarn and greisen, which are located in the northern and southern contact zones between the Chuandu intrusion, and the Devonian limestone and the Cambrian

IP

T

sandstone-slate. Metallic minerals include principally molybdenite, scheelite, wolframite,

SC R

pyrite and minor chalcopyrite.

3 Analytical method and Samples

NU

3.1 Zircon U-Pb dating

Zircon grains were separated from small rock samples (1 kg) using the standard separation

MA

techniques, i.e., handpicking under microscope after a combined density-magnetic separation.

D

The separated zircon grains were then mounted in epoxy and polished. Optical microscopic

TE

and cathodoluminescent images of zircon separates were used to ensure that the least fractured, inclusion-free zones of zircon grains were selected for laser ablation. The zircon

CE P

U-Pb dating was carried out in the State Key Laboratory of Isotope Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences (GIG-CAS). Laser

AC

ablation was conducted using a pulsed Resonetic 193 nmArF excimer laser operated at a constant energy of 100 mJ, with a repetition rate of 8 Hz and a spot of 31μm in diameter. The ablated aerosol was carried from a specially designed sample cell to an Agilent 7500a ICP-MS by He gas via a Squid system to smooth signals (Li et al., 2012; Tu et al., 2011). Temora zircon standard (Black et al., 2003) and NIST 610 standard glass (Pearce et al., 1997) were ablated in each rotation of unknown zircons (five analyses each). The final age data and Concordia plots were acquired using the software ISOPLOT (Ludwig, 2003). All data for the analyzed samples were processed using cumulative probability plots to identify Pb inheritance and/or Pb loss. Cumulative probability plots feature a nonlinear scale

ACCEPTED MANUSCRIPT along the x-axis that is calibrated to represent a normal distribution as a straight line with a positive slope. Data lying above or below the projection of the straight line are explained to

IP

T

be Pb inheritance and Pb loss, respectively (Liang et al., 2007). U-Pb age of the main

SC R

population, obtained by removing the data of inherited cores of zircons and zircons suffering Pb loss, is explained to be the cooling or crystallization age of the intrusion. 3.2 Zircon Lu-Hf isotope

NU

In situ Hf isotope measurements were carried out using a Neptune Plus MC-ICPMS at the

MA

isotope laboratory of GIG-CAS. Laser ablation was conducted using a Resolution M-50 laser operated at a constant energy of 80 mJ, with a repetition rate of 8 Hz and a spot of 45μm in

D

diameter. Detailed analytical procedures, instrumental conditions and data acquisition were 176

Hf/177Hf ratio of 0.282015

TE

given by Wu et al. (2006). Zircon GJ-1 with the recommended

CE P

was used as the secondary standard for data quality assessment. Model ages of the analyzed samples were calculated, based on the assumption that the 176Lu/177Hf ratio of average crust is

AC

0.015, and (176Hf/177Hf)CHUR and (176Lu/177Hf)CHUR of the present-day chondrite and depleted mantle are 0.282772 and 0.0332, and 0.28325 and 0.0384, respectively (Blichert-Toft and Albarede, 1997; Griffin et al., 2002). The decay constant of

Lu used for this study is λ =

176

1.867×10-11 (Scherer et al., 2001). 3.3 Whole rock major and trace element analysis Major element compositions of less altered samples were analyzed using the standard X-ray fluorescence method at the isotope laboratory of IGG-CAS. The analytical uncertainties for major elements are estimated to be lower than 5% (Li et al., 2005). Trace elements were determined on a Bruker Aurora M90 inductively-coupled plasma mass

ACCEPTED MANUSCRIPT spectrometry (ICP-MS) using the method of Qi et al. (2000). The accuracies of the ICP-MS analyses are estimated to be better than ±5-10% for most elements.

IP

T

3.4 Whole-rock Sr-Nd isotope

SC R

The Sr and Nd isotopic compositions of less altered samples were analyzed using a method similar to that of Chu et al. (2009). The 87Sr/86Sr and 143Nd/144Nd isotopic ratios were measured using a Neptune Plus multi-collection mass spectrometry equipped with nine

NU

Faraday cup collectors and eight ion counters. During the Sr and Nd measurements, the

146

86

Sr/88Sr=0.1194 and

MA

normalizing factors used to correct the mass fractionation were

Nd/144Nd=0.7219. NIST SRM-987 and JMC-Nd were used as certified reference standard 87

Sr/86Sr and

143

Nd/144Nd isotopic ratios, respectively and BCR-1 and

D

solutions for the

CE P

4. Results

TE

BHVO-1 were used as the reference materials.

4.1 Zircon U-Pb ages and Lu-Hf isotopic compositions

AC

Rock samples for the main rock types of the Dabaoshan porphyries (monzogranite porphyry and granite porphyry) and its adjacent Chuandu porphyritic monzogranite were dated to determine their crystallization ages and for age differences between the 2 different types of ore-bearing porphyries. Zircon U-Pb ages for various rocks of the Dabaoshan porphyries and its adjacent Chuandu porphyritic monzogranite are listed in Table 1. The Concordia and probability plots are shown in Figs. 3a, b, c. The Dabaoshan monzogranite porphyry and granite porphyry have zircon U-Pb ages of 166.3±2.0 Ma with MSWD=1.9 and 166.2 ± 2.7 Ma with MSWD = 2.7, respectively. The Chuandu porphyritic monzogranite has zircon U-Pb age of 162.1 ± 1.6 Ma with MSWD =

ACCEPTED MANUSCRIPT 2.7 (Fig.3c).

In both cases cathodoluminescence shows tight concentric banding around

obvious inherited cores, with the cores giving ages as old as 850 Ma with a significant

176

Hf/177Hf ratios ranging from 0.282302 to

SC R

Zircons from the Dabaoshan porphyries have

IP

T

“Panafrican” aged component (Figure 4).

0.282461, Ɛ Hf(t) values from -13.21 to -7.51, and TDM2 ages ranging from 1682 to 2045 Ma (Table 2) (average of 1.78 Ga). Note that the Ɛ Hf(t) values are much more negative than those

MA

Cathaysia Block (Li et al., 2003, 2004).

NU

of the Middle Jurassic (168-178 Ma) intraplate basalts and gabbros (Ɛ Hf(t) = -2.7 to +7.9) of the

4.2 Major and trace elements and Sr-Nd isotopic compositions

D

The least altered samples were selected for major and trace elements and Sm-Nd and Rb-Sr

TE

isotope analyses. Although only the relatively fresh samples were selected for the analysis, the

CE P

modest loss on ignition (LOI) values (1.41-4.80), primarily reflecting variant H2O and CO2 concentrations in most samples, suggest that the analyzed samples had undergone some

AC

hydrothermal alteration. Such processes could have modified the contents of mobile elements, such as Na, K, Ca Rb, Ba and Sr (Fig 5a, 5b). Thus we use only immobile elements (e.g., high field strength elements and REE) to describe the original geochemical characteristics of the rocks. The Dabaoshan porphyries are characterized by low TiO2 (<0.5 wt %) and P2O5 (0.25 wt %), and high SiO2 (64.42-75.41 wt %). The Dabaoshan porphyryies are rich in K2O, with K2O/Na2O values in the range of 4.55 to 8.54. In the plot of SiO2 vs. Zr/TiO2 (Winchester and Floyd, 1977), they plot mainly in the field of rhyodacite–dacite (Fig 6a). In the diagram of Th vs Co (Hastie et al., 2007), the Dabaoshan porphyries are of high-K calc-alkaline and

ACCEPTED MANUSCRIPT shoshonite series (Fig 6b). The Dabaoshan porphyries for which we have trace element data are characterized by

IP

T

highly fractionated LREE/HREE with [La/Yb]N=14.6-35.0 and weak negative Eu anomalies

SC R

(Fig. 7), indicative of modest fractional crystallization of plagioclase (Weill and Drake, 1973). The Dabaoshan porphyries, which are relatively enriched in large ion lithophile element (LILE) with positive Cs, Rb, Th, U, Pb anomalies and negative Nb, Ta and Ti anomalies as shown by

NU

the primitive mantle normalized trace element spider diagrams, have features similar to those of

MA

typical rocks from convergent plate margins (Fig. 7).

The high Rb/Sr (Table 4) of the Dabaoshan porphyries could be caused by the hydrothermal

D

alteration as indicated by the negative relationship between Rb and Sr contents and the high

TE

LOI (Fig. 5a, b), and thus are unrepresentative. The strontium isotopic compositions of the

CE P

Dabaoshan porphyries are, therefore, not discussed in the text. The Dabaoshan porphyries have Nd/144Nd ranging from 0.51214 to 0.51298 with Ɛ Nd(t) values in the range of -8.20 to -6.61

143

AC

and TDM ages of 1.30 to 1.43 Ga.

5. Discussion

5.1 Ages of the porphyries associated with Mo mineralization. Previous studies reported some different ages for the Dabaoshan porphyries and the adjacent Chuandu porphyritic monzogranite associated with Mo mineralization in northern Guangdong. Wang et al. (2011a) reported that LA-ICP-MS zircon U-Pb ages of the Dabaoshan and the Chuandu intrusive rocks are 175.8±1.5 Ma and 175.0±1.7 Ma, respectively. However, Li et al. (2012) presented a crystallization age of 166±1 Ma (zircon LA-ICP-MS U-Pb) for the Dabaoshan porphyries.

ACCEPTED MANUSCRIPT The Dabaoshan porphyries consist mainly of the monzogranite porphyry and granite porphyry. Our new zircon LA-ICP-MS U-Pb data indicate that the Dabaoshan monzogranite

IP

T

porphyry and granite porphyry have U-Pb ages of 166.3±2.0 Ma with MSWD=1.9 and

SC R

166.2±2.8 Ma with MSWD=2.7, respectively, the same age for the two samples within uncertainty. The good agreement among LA-ICP-MS zircon U-Pb ages (166.2-166.3 Ma), the zircon U-Pb age (166±1 Ma) of Li et al. (2012), and the Re-Os isochron age (166.0±3.0 Ma)

NU

of Qu et al. (2014) indicate a petrogenetic relationship between Mo mineralization and

MA

emplacement of that the Dabaoshan porphyries formed at about 166 Ma rather than 175 Ma. And, importantly, the Chuandu porphyritic monzogranite is 162.1±1.6 Ma, an age distinctly

D

younger than that of the Dabaoshan, and clearly different from the previously suggested 175

CE P

Mo mineralization.

TE

Ma age. Our data indicate that there were at least two pulses of magmatism associated with the

5.2 Possible sources and petrogenesis of the Dabaoshan porphyries

AC

The sources of the Dabaoshan porphyries are controversy (Li et al., 2012; Wang et al., 2011b; Zhong et al., 2013). Wang et al. (2011a) argued that the Dabaoshan porphyries were derived from mixed crustal and mantle sources. Li et al., (2012) suggested that the Dabaoshan porphyries were derived from partial melting of metamorphosed sediments in back arc basins (Li et al., 2012). The geochemical features of the Dabaoshan porphyries, such as high K2O/Na2O ratios, high LILE concentrations, LREE enrichment, and strong negative Nb, Ta and Ti anomalies, all suggest crustal sources. The moderately negative Ɛ Nd(t) values of -6.6 to -8.2 also indicate a dominantly crustal origin (Fig. 8a). Their zircon Ɛ Hf(t) values are significantly more negative

ACCEPTED MANUSCRIPT than the CHUR reference line (Fig. 8b) with the TDM2 ranging from 1686 to 2045Ma, which, on average, are similar to the peak TDM2 (~1.7 Ga) of the basement rocks in the western part of the

IP

T

Cathaysia Block (Xu et al., 2007). The features of Ɛ Nd(t) and Ɛ Hf(t) values of the Dabaoshan

SC R

porphyries demonstrate that they were dominantly derived from partial melting of the Proterozoic crust. The Ɛ Nd(t) values (-6.6 to -8.2) of the Dabaoshan porphyries are much lower than those (-2.7 to +7.9) of the Middle Jurassic (168-178 Ma) intraplate basalts and gabbros in

NU

the Cathaysia Block (Li et al., 2003; Li et al., 2004), and those of the Dexing porphyries (Wang

MA

et al., 2006). Thus the Dabaoshan porphyries could not be generated through fractionation crystallization (FC) processes of these basaltic magmas. Moreover, the high content of SiO2

D

(64.42 - 76.32%) in the Dabaoshan porphyries and the absence of the early Yanshanian mafic

TE

rocks exposed in the Dabaoshan ore field in northern Guangdong (GDGBMR, 1985) preclude

CE P

significant material involvement of mantle-derived material during the formation of the Dabaoshan porphyries.

AC

The inherited cores of zircon grains from the Dabaoshan porphyries with U-Pb ages varying from Proterozoic to Triassic (Table 1, Fig 3), provide direct evidence for the involvement of old crystalline rocks or sediments during the genesis of the Dabaoshan porphyries, either in the source or as contaminant. It is reasonable to conclude that the inherited Proterozoic zircon grains could be derived from the source region of the Dabaoshan porphyries, while those of younger ones could be the result of crustal contamination. In diagrams of La/Yb vs Yb (Fig. 9a) and Ni vs Th (Fig.9b), the samples of the Dabaoshan porphyry show a slight fractionation crystallization trend, suggesting that the partial melt of old crust did experience some fractionation crystallization. Sources and conditions of that partial

ACCEPTED MANUSCRIPT melting is constrained by the peraluminous nature of the granites and the fact that peraluminousitiy correlates with increasing K2O/Na2O which in turn correlates with

IP

T

temperature and pressure (Hermann and Spandler, 2008). On this basis we suggest these

SC R

granites formed by partial melting of crustal rocks at high temperature and high pressure. The Zr saturation temperature of the Dabaoshan porphyries ranges from 738 to 876 C (Table 3, method after Watson and Harrison, 1983), indicating that the rocks were formed by the

NU

crystallization of relatively high-temperature magmas.

MA

Monazite is the main host of LREE, Th and U in felsic crustal rocks and it has a preference of LREE and Th over U (Stepanov et al., 2012). Low degrees of partial melting at low

D

temperature may result in residual monazite left in the source. Thus, the resultant melts are

TE

characterized by Th/U ratios lower than those of the protolith. High degree partial melting at

CE P

high temperature may consume monazite in the sources, and as a result the melts will have Th/U ratios inherited from their sources (Stepanov et al., 2012). The Dabaoshan porphyries

AC

have an average Th/U of 5.0, which is similar to that of the Cathaysia Proterozoic crystalline basement (Th/U = 5.3-5.4, Ma and Chen, 2000). It is possible that the porphyries were derived from high degree partial melting of the Cathaysia Proterozoic crystalline basement at high temperature. Previous publications show that melt Nb/Ta is controlled by the residual minerals that contain titanium (Stepanov et al., 2012; Xiao et al., 2006). Titanium-bearing minerals in these compositions mainly include biotite/phengite, rutile and titanite/ilmenite (Ding et al., 2013; Ding et al., 2009). If the residual Ti-bearing hosted mineral is biotite/phengite, the Nb/Ta ratios of the melts will be lower than those of their protolith. The Nb/Ta ratios of partial melts will be

ACCEPTED MANUSCRIPT similar to or higher than those of the protolith if the residual Ti-bearing mineral is rutile, while the Nb/Ta ratios of partial melts will be much higher than those of the protolith if the residual

IP

T

Ti-bearing is titanite/ilemenite (Ding et al., 2013; Ding et al., 2009; Stepanov et al., 2012). The

SC R

Dabaoshan porphyries have an average Nb/Ta value of 11.8, the same approximate levels as the average value of 12.4 for the Protorozoic crystalline basement in western Guangdong (Zhou et al., 2015) and the upper crust (Barth et al., 2000; Rudnick and Fountain, 1995). The Nb/Ta

NU

ratios of the Dabaoshan porphyries suggest that the melts were formed by high degrees of

MA

partial melting of a Protorozoic crystalline basement with rutile as the residual Ti-bearing phase. In addition, the Dabaoshan porphyries are characterized by weak or no Eu negative

D

anomalies, indicating that plagioclase was not left in restite. The absence of plagioclase in

TE

restite requires either that the partial melting occurred under the conditions for the eclogite

CE P

facies (no plagioclase; Campbell et al., 2014) or that all plagioclase in the source was consumed in the melting reactions. The high La/Yb of the porphyries indicate that garnet was a restitic

AC

phase, further indicating a garnet-present/plagioclase-absent type source composition Characteristics of whole rock Nd and zircon Hf isotope compositions, together with the LREE enrichment, and the high K2O/Na2O, (La/Yb)N, Th/U and Nb/Ta ratios of the Dabaoshan porphyries, suggest that they were derived from the partial melting of the Cathasyia Proterozoic basement without significant material input from the mantle. 5.3 Possible water source for the formation of high oxidized magma It is agreed generally that parental magmas of porphyry Cu ± Mo ± Au systems are water-saturated and highly oxidized (Ballard et al., 2002; Candela, 1992; Hedenquist and Lowenstern, 1994; Liang et al., 2006; Lu et al., 2015; Mungall, 2002; Sillitoe, 2010; Stern et al.,

ACCEPTED MANUSCRIPT 2007; Sun et al., 2015; Sun et al., 2013; Sun et al., 2012a; Sun et al., 2010; Zhang et al., 2013). Water content of the magmatic sources play a critical role in the amount of melting of the

IP

T

oxidized magma, and the ensuing order of crystallization (Campbell et al., 2014). In subduction

SC R

zones, the high water content of metal-fertile porphyry melts could result from dehydration and partial melting of oceanic crust that is dragged down during subduction which in turn fluxes overlying mantle. However, the Dabaoshan porphyry Mo deposit in northern Guangdong was

NU

formed in a continental environment along the deep fault zone. Where did the water come from

MA

for the formation of the water-saturated melts that are genetically associated with the Mo mineralization? Low grade metamorphic rocks dominate the Cathaysia block. Sources of water

D

to aid high degree partial melts, and to oxidize the magma could be derived from hydrous

TE

minerals such as amphibole, zoisite, mica and clay minerals.

CE P

In the Triassic, the SCB was under compression due to its collision with the Indochina Block and the North China Block (Ames et al., 1993; Carter et al., 2001; Sun et al., 2002). The

AC

continental crust of the SCB in the Triassic could have been over-thickened (Li et al., 2003; Li et al., 2004). The source rocks might be metamorphosed from schist facies to amphibolite facies-granulite facies in the middle crust, and from amphibolite facies-granulite facies to eclogite facies in the lower crust due to the increasing temperature and pressure. The high-density of the garnet-bearing eclogite in the lower crust could cause delamination (Xu et al., 2002) or founder (Arndt and Goldstein, 1989). Hydrous minerals, such as the epidotite group, amphibole group, mica group and staurolite, could release water during the transformation from medium to high grade metamorphism as shown in the following reactions: (Mg,Fe)5Al(AlSi3O10)(OH)6 + SiO2→(Mg, Fe)2Al4Si5O18+(Mg, Fe, Al)7(Si, Al)8O22(OH)2+

ACCEPTED MANUSCRIPT H2O chlorite

quartz

cordierite

anthophyllite

almandine

sillimanite

IP

quartz

water

SC R

staurolite

T

Fe2Al9O6(SiO4)4(OH)2 +SiO2→Fe3Al2(SiO4)3 + Al2SiO5+ H2O

water

4Ca2(Al, Fe)3Si3O12(OH)+ SiO2 → 5CaAl2Si2O8+(Ca, Fe2+)3Al2(SiO4)3 +2H2O quartz

plagioclase

Al2Si4O10(OH)2 →Al2SiO5 + 3SiO2 +H2O andalusite

quartz

water

water

MA

pyrophyllite

grossularite

NU

clinozoisite

Mg7Si8O22(OH)2 → 7MgSiO3 + SiO2 + H2O enstatite

quartz

water

D

anthophyllite

TE

2Ca2Mg5Si8O22(OH)2 → 3Mg2(SiO3)2 + 4CaMg(SiO3)2 + 2SiO2 + 2H2O. enstatite

CE P

tremolite

diopsite

quartz

water

KAl2(AlSi3O10)(OH)2+SiO2→KAlSi3O8 +Al2SiO3 + H2O quartz

K-feldspar

andalusite

water

AC

phengite

The H2O-rich fluids released during metamorphic dehydration might be pushed to local low-pressure domains in the deep fault zone during the Caledonian or Indosinian orogeny. These local domains along the deep fault zone could be modified by the H2O-rich fluids and become water-saturated. Partial melting of these domains could form hydrous and oxidized magmas which favor the porphyry mineralization. 5.4 Tectonic model for the Dabaoshan porphyry deposit Various models of the tectonic setting have been proposed for the formation of porphyry deposits in northern Guangdong, such as 1) continental arc setting related to the westward

ACCEPTED MANUSCRIPT subduction of the paleo-Pacific plate (Zhong et al., 2013), 2) extensional environment associated with the rollback of the southwestward subduction of the paleo-Pacific plate (Li et

IP

T

al., 2012; Sun et al., 2012b; Wang et al., 2011a), and 3) post-collisional extensional setting

SC R

(Wang et al., 2011b).

The forming ages of the porphyry deposits along the Shi-Hang rift zone do not decrease from northwest to southeast (Fig. 1), which is inconsistent with the model that porphyry

NU

deposits were related to westward subduction of the paleo-Pacific plate. Arc magmas are

MA

characterized by Th/U of 1.5 to 3.0, whereas Th/U of the upper continental crust and the bulk Earth are around 4 (Taylor and McLennan, 1985). Th/U of the Dabaoshan porphyries (in range

D

of 3.3 to 8.4 with an average of 5.0) are inconsistent with the subduction-related arc magmas

TE

(Zhong et al., 2013). Moreover, the Dabaoshan porphyries are mainly plotted in the field

CE P

between VAG-Syn-COLG and WPG (Fig.10a), and Syn-COLG and WPC (Fig.10b) in the trace element discrimination diagrams (Pearce et al., 1984), which are against the affinity of

AC

continental arc setting. If the porphyry deposits in northern Guangdong owe their origin to slab rollback, porphyry deposits with comparable forming ages should be found along the rollback zone, which should be perpendicular to the southwestward subduction of the paleo-Pacific plate. Porphyry Mo deposits, including two large and one medium-sized deposits, in northern Guangdong are distributed mainly along the Wuchuan-Sihui deep fault zone (Fig. 1). The close spatial relationship between the porphyry deposits and the Wuchuan-Shishui deep fault zone in northern Guangdong is unlikely to be coincidences. The Wuchuan-Sihui fault (shear) zone, initiated in the Early Ordovician, dissects the entire lithosphere (GCGBMR, 1985). It is,

ACCEPTED MANUSCRIPT therefore, a linear weak belt in the crust. The South China block was affected by either the southwestward subduction of the paleo-Pacific plate from 170 to 125 Ma (Sun et al., 2007) or

IP

T

the westward low angle (Zhou et al., 2006) or flat subduction of the paleo-Pacific plate (Li and

SC R

Li, 2007) from Permian to Mesozoic. Since the Wuchuan-Sihui deep fault was a preexisting weak belt in the crust, it could have been reactivated by subduction of the paleo-Pacific plate, which then could induce the linear upwelling of hot asthenosphere mantle along the deep fault

NU

zones. Partial melting of the water-saturated domains in the deep fault zone could be triggered

MA

by the heat conducted from the upwelling asthenosphere mantle. Magmas formed by the partial melting of water-saturated domains in the deep fault zone were hydrous and oxidized,

D

which will favor the porphyry mineralization.

TE

Based on the above discussion and the close relationship between porphyry deposits and

CE P

the deep fault, the following model is proposed for the formation of the Dabaoshan and other porphyry Mo deposits along the Wuchuan-Sihui deep fault zone: (1) During the Caledonian

AC

and Indosinian orogeny, the crust was thicken and metamorphic dehydration was occurred in the lower crust. The metamorphic dehydrating-fluids were pushed to the low press domains in Wuchuan-Sihui fault zone. The domains were modified by these fluids and became water-saturated (Fig 11a); (2) During Jurassic (~166Ma), subduction of paleo-Pacific plate caused the reactive of Wuchuan-Sihui fault, which triggered the upwelling of asthenosphere. The heat conducted from the upwelling asthenosphere could cause partial melting of the water-saturated domains and form hydrous and oxidized magmas in the deep fault zone. Emplacements of these magmas along the Wuchuan-Sihui fault ultimately formed the Dabaoshan and other porphyry deposits along the deep fault zone in North Guangdong (Fig

ACCEPTED MANUSCRIPT 11b). 5.5 Implications for porphyry ore prospecting in northern Guangdong

IP

T

The geological and geochemical features of the Dabaoshan porphyry deposit suggest that it

SC R

was formed in a intracontinental setting rather than arc setting where porphyry deposits predominantly occur all over the world. The Dabaoshan porphyry Mo deposit is likely related to the magmatism triggered by the heat conducted from the upwelling of asthenospheric mantle

NU

along the Wuchuan-Sihui deep fault zone. The formation of the Dabaoshan porphyry Mo

MA

deposit was controlled by the structural activities of the Wuchuan-Sihui deep fault zone. The area along the Wuchuan-Sihui fault zone, therefore, has greater potential in porphyry ore

D

prospecting than previously thought. The Linwan large and Jilongshan medium-sized porphyry

TE

Mo deposits found along the Wuchuan-Sihui fault zone also support a genetic link with the

CE P

activities of the deep fault zone (Fig 1). More attention, therefore, should be paid to porphyry ore prospecting along the Wuchuan-Sihui deep fault zone.

AC

Porphyry deposits occur not only in subduction zones and continental collision zones, but also along deep fault zones in an intracontinental environment. More attention should be paid to porphyry ore prospecting along deep fault zones in intracontinental environments.

6 Conclusions

The Dabaoshan porphyry Mo deposit has zircon LA-ICP-MS U-Pb age of about 166 Ma and the adjacent Chuandu porphyritic monzogranite associated with greisen and skarn Mo mineralization has a distinct zircon LA-ICP-MS U-Pb age of 162 Ma. We interpret at least two pulses of magmatic activities associated with the Mo mineralization in the Dabaoshan deposit. The Dabaoshan porphyries were derived from a high degree of partial melting of the

ACCEPTED MANUSCRIPT Proterozoic rocks without significant material contributions of mantle source. The Dabaoshan porphyry Mo deposit was formed in the intracontinental environment

SC R

by subduction of the paleo-Pacific plate during the Jurassic.

IP

T

rather than arc setting, and owes its origin to the Wuchuan-Sihui deep fault activities induced

Metamorphic dehydration of H2O-rich fluids should have played a key role in the formation of the highly oxidized magmas associated with porphyry Mo mineralization along deep fault

MA

Acknowledgements

NU

zones in the interior of the continent.

D

We thank the Geological department of the Dabaoshan mining company for their assistance

TE

during our field work. Huang WT is indebted to the postdoctoral foundation of CAS. This work was supported by the Natural Science Foundation of China (41172080, 41272099, 41502073

CE P

and 41421062). Constructive reviews by Prof. Xing-Chun Zhang and an anonymous referee are gratefully acknowledged. We sincerely thank Dr Charllote Allen for her suggestions and

AC

passional help in revising the manuscript, which led to a better presentation of the final product.

Figure captions Fig. 1 Simplified map showing the distribution of porphyry deposits along the Shi-Hang rift zone (modified after Mao et al., 2013) and in the Wuchuan-Sihu deep fault zone (modified after Xu, 2013) (a) and geological sketch map of the Dabaoshan ore field (b). Ages of the Dexing, the Yongping, the Baoshan and the Yuanzhuding porphyries are from Wang et al., (2006), Zhu et al. (Zhu et al., 2008), Wang et al., (2002) and Zhong et al., (2013), respectively

ACCEPTED MANUSCRIPT

Fig. 2 Photos of Dabaoshan porphryry Mo deposit and Chuandu porphyritic monzogranite: (a)

IP

T

contact between the Dabaoshan porphyries and volcanic rock; (b) and (c) Dabaoshan

SC R

monzogranite porphyry showing the porphyritic texture and phenocrysts of plagioclase (altered to sericite), quartz, muscovite, K-feldspar; (d) and (e) quartz-molydenite and quartz pyrite veins in the Dabaoshan porphyry; (f) texture and quartz-K-feldspar veinlet

MA

NU

(potassic-silicic alteration) of the Chuandu porphyritic monzogranite.

Fig. 3 Concordia plots showing the zircon U-Pb data of the Dabaoshan porphyries and the

TE

D

Chuandu porphyritic monzgranite. The insets are probability plots.

CE P

Fig. 4 Cathodoluminescence images for zircon grains from the Dabaoshan porphyries showing analyzed points with various U-Pb ages. U-Pb ages <190 Ma were obtained at

AC

the rim of zircon crystals or at the centers of zircon grains without old cores, U-Pb ages >200 Ma were gained at the old core of zircon grains.

Fig. 5 LOI against the Rb and Sr.

Fig. 6 (a) Plot of SiO2 against Zr/TiO2 (after Winchester and Floyd, 1977) for classification of the rocks; and (b) plot of Th against Co (after Hastie et al., 2007).

Fig. 7 Primitive mantle normalized trace element spider diagrams (a) and chondrite

ACCEPTED MANUSCRIPT normalized rare earth element patterns (b) for the Dabaoshan porphyries.

IP

T

Fig. 8 Plot of zircon ages against Hf(t) (a) and Nd(t) (b) values for the Dabaoshan porphyries.

SC R

Data of Middle Jurassic within-plate basalts and gabbros in the Cathaysia Block are from Li et al., (2003, 2004), data of the Dexing porphyries are from Wang et al. (2006) and

NU

data of the Preterozoic crust of the Cathasyia Block are from Sun et al. (2005).

MA

Fig. 9 Plot of La/Yb against La (a) and Ni against Th (b) for the Dabaoshan porphyries.

D

Fig. 10 Plot of Nb against Y (a) and Rb against Y+Nb (b). WPG: within-plate granites, VAG:

CE P

(Pearce et al., 1984).

TE

volcanic-arc granite, Syn-COLG: syn-collision granite, ORG: ocean-ridge granites

AC

Fig. 11 Tectonic model for the Dabaoshan and other porphyry Mo deposits along the Wuchuan-Sihui deep fault zone in the northern Guangdong, South China.

ACCEPTED MANUSCRIPT

References

T

Ames, L., Tilton, G. R., Zhou, G. Z., 1993. Timing of Collision of the Sino-Korean and

IP

Yangtze Cratons U-Pb zircon dating of coesite-bearing eclogites. Geology 21, 339-42.

SC R

Arndt, N. T., Goldstein, S. L., 1989. An open boundary between lower continental-crust and mantle - Its role in crust formation and crustal recycling. Tectonophysics 161, 201-12.

NU

Ballard, J. R., Palin, J. M., Campbell, I. H., 2002. Relative oxidation states of magmas inferred from Ce(IV)/Ce(III) in zircon: application to porphyry copper deposits of

MA

northern Chile. Contrib Mineral Petr 144, 347-64.

D

Barth, M. G., McDonough, W. F., Rudnick, R. L., 2000. Tracking the budget of Nb and Ta in

TE

the continental crust. Chem Geol 165, 197-213. Black, L. P., Kamo, S. L., Allen, C. M., Aleinikoff, J. N., Davis, D. W., Korsch, R.

CE P

J.,Foudoulis, C., 2003. TEMORA 1: a new zircon standard for Phanerozoic U-Pb geochronology. Chem Geol 200, 155-70.

AC

BlichertToft, J., Albarede, F., 1997. The Lu-Hf isotope geochemistry of chondrites and the evolution of the mantle-crust system. Earth Planet Sc Lett 148, 243-58. Campbell, I. H., Stepanov, A. S., Liang, H. Y., Allen, C. M., Norman, M. D., Zhang, Y. Q.,Xie, Y. W., 2014. The origin of shoshonites: new insights from the Tertiary high-potassium intrusions of eastern Tibet. Contrib Mineral Petr 167. Camus, F., Dilles, J. H., 2001. A special issue devoted to porphyry copper deposits of northern Chile - Preface. Econ Geol Bull Soc 96, 233-7. Candela, P. A., 1992. Controls on ore metal ratios in granite-related ore systems - an experimental and computational approach. T Roy Soc Edin-Earth 83, 317-26.

ACCEPTED MANUSCRIPT Carter, A., Roques, D., Bristow, C., Kinny, P., 2001. Understanding Mesozoic accretion in Southeast Asia: significance of Triassic thermotectonism (Indosinian orogeny) in

IP

T

Vietnam. Geology 29, 211-4.

SC R

Chen, F. W., Li, H. Q., Wang, D. H., Xiao, G. M., Yang, X. J., Gao, Y. W., Mei, Y. P.,G., L. X., 2012. Geological characteristics and diagenetic—metallogenic chorological study of the Yuangzhuding porphyry Cu-Mo deposit, western Guangdong province. Acta Geologica

NU

Sinica 86, 1298-305 (in Chinese with English abstract).

MA

Chen, J. F., Jahn, B. M., 1998. Crustal evolution of southeastern China: Nd and Sr isotopic evidence. Tectonophysics 284, 101-33.

D

Chen, Y. J., 2002. Several important problems in study of regional metallogenesis in China:

TE

Their relationship to continental collision. Earth Science Frontiers 9, 319-28 (in Chinese

CE P

with English abstract).

Chen, Y. J., 2013. The development of continental collision metallogeny and its application.

AC

Acta Petrol Sin 29, 1-17 (in Chinese with English abstract). 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 mechanism and type. Science in China (Series D) 43 (Suppl. ), 82-94. Chen, Y. J., Li, N., 2009. Nature of ore-fluids of intracontinental intrusion-related hypothermal deposits and its difference from those in island arcs. Acta Petrol Sin 25, 2477-580 (in Chinese with English abstract). Chen, Y. J., Wang, P., Li, N., Yang, Y. F., Pirajno, F., 2016. The collision-type porphyry Mo deposits

in

Dabie

Shan,

China.

Ore

Geology

Reviews,

ACCEPTED MANUSCRIPT http://dx.doi.org/10.1016/j.oregeorev.2016.03.025. Chu, Z. Y., Chen, F. K., Yang, Y. H., Guo, J. H., 2009. Precise determination of Sm, Nd

IP

T

concentrations and Nd isotopic compositions at the nanogram level in geological samples

SC R

by thermal ionization mass spectrometry. J Anal Atom Spectrom 24, 1534-44. Cooke, D. R., Hollings, P., Walsh, J. L., 2005. Giant porphyry deposits: Characteristics, distribution, and tectonic controls. Econ Geol 100, 801-18.

NU

Ding, X., Hu, Y. H., Zhang, H., Li, C. Y., Ling, M. X.,Sun, W. D., 2013. Major Nb/Ta

MA

Fractionation Recorded in Garnet Amphibolite Facies Metagabbro. J Geol 121, 255-74. Ding, X., Lundstrom, C., Huang, F., Li, J., Zhang, Z. M., Sun, X. M., Liang, J. L.,Sun, W. D.,

D

2009. Natural and experimental constraints on formation of the continental crust based

TE

on niobium-tantalum fractionation. Int Geol Rev 51, 473-501.

CE P

GDGBMR (Bureau of Geology and Mineral Resources of Guangdong Province), 1985. Reginal Geology of the Guangdong Province. Beijing, China: Geological Publishing

AC

House; p. 350 (in Chinese with Englishi summary). Griffin, W. L., Wang, X., Jackson, S. E., Pearson, N. J., O'Reilly, S. Y., Xu, X. S.,Zhou, X. M., 2002. Zircon chemistry and magma mixing, SE China: In-situ analysis of Hf isotopes, Tonglu and Pingtan igneous complexes. Lithos 61, 237-69. Gu, J. Y., Wu, Q. Y., Liao, X. P., 1984. Continental subvolcanic-volcanic activities and geneisis of Dabaoshan polymetallic mineralization. Geology and Exploration, 2-8 (in Chinese). Gilder, S. A., Keller, G. R., Luo, M., and Goodell, P. C., 1991. Eastern Asia and the Western Pacific timing and spatial distribution of rifting in China. Tectonophysics 197, 225-243.

ACCEPTED MANUSCRIPT Goodell, P. C., Gilder, S., and Fang, X., 1991. A preliminary description of the Gan-Hang failed rift, southeastern china. Tectonophysics 197, 245-255.

IP

T

Hastie, A.R., Kerr, A. C., Pearce, J. A., Mitchell, S. F., 2007. Classification of altered volcanic

SC R

island arc rocks using immobile trace elements: development of the Th-Co discrimination diagram. J Petrol 48, 2341-2357.Hedenquist, J. W., Lowenstern, J. B., 1994. The Role of Magmas in the Formation of Hydrothermal Ore-Deposits. Nature 370,

NU

519-27.

MA

Hermann, J., Spandler, C. J., 2008. Sediment melts at sub-arc depths: An experimental study. J Petrol 49, 717-40.

D

Hou, Z. Q., Pan, X. F., Li, Q. Y., Yang, Z. M., Song, Y. C., 2013a. The giant Dexing porphyry

TE

Cu-Mo-Au deposit in east China: product of melting of juvenile lower crust in an

CE P

intracontinental setting. Miner Deposita 48, 1019-45. Hou, Z. Q., Yang, Z. M., Lu, Y. J., Kemp, A., Zheng, Y. C., Li, Q. Y., Tang, J. X., Yang, Z.

AC

S.,Duan, L. F., 2015. A genetic linkage between subduction- and collision-related porphyry Cu deposits in continental collision zones. Geology 43, 247-50. Hou, Z. Q., Yang, Z. M., Qu, X. M., Meng, X. J., Li, Z. Q., Beaudoin, G., Rui, Z. Y., Gao, Y. F.,Zaw, K., 2009. The Miocene Gangdese porphyry copper belt generated during post-collisional extension in the Tibetan Orogen. Ore Geol Rev 36, 25-51. Hou, Z. Q., Yang, Z. M., Zheng, Y. C., Tang, J. X.,Yang, Z. S., 2013b. Collision- and subduction-related porphyry Cu deposits in Tibetan orogen: a possible genetic linkage. Mineral Deposit Research for a High-Tech World, Vols 1-4, 1420-3. Huang, H. L., Zheng, J. Y., 2001. Research on kinematic characteristics of the Wuchuan-Sihui

ACCEPTED MANUSCRIPT fault zone. Uranium Geology 17, 34-43 (in Chinese with English abstract). Li, C. Y., Zhang, H., Wang, F. Y., Liu, J. Q., Sun, Y. L., Hao, X. L., Li, Y. L.,Sun, W. D., 2012.

IP

T

The formation of the Dabaoshan porphyry molybdenum deposit induced by slab rollback.

SC R

Lithos 150, 101-10.

Li, X. H., Chen, Z., Liu, D. Y., Li, W. X., 2003. Jurassic gabbro-granite-syenite suites from Southern Jiangxi province, SE China: Age, origin, and tectonic significance. Int Geol

NU

Rev 45, 898-921.

MA

Li, X. H., Chung, S. L., Zhou, H. W., Lo, C. H., Liu, Y., Chen, C. W., 2004. Jurassic intraplate magmatism in southern Hunan-eastern Guangxi: Ar40/Ar39 dating, geochemistry, Sr-Nd

TE

226, 193-215.

D

isotopes and implications for the tectonic evolution of SE China. Geol Soc Spec Publ

CE P

Li, X. H., Mc Culloch, M. T., 1996. Secular variation in the Nd isotopic composition of Neoproterozoic sediments from the southern margin of the Yangtze Block: Evidence for

AC

a proterozoic continental collision in southeast China. Precambrian Res 76, 67-76. Li, X. H., Qi, C. S., Liu, Y., Liang, X. R., Tu, X. L., Xie, L. W.,Yang, Y. H., 2005. Petrogenesis of the Neoproterozoic bimodal volcanic rocks along the western margin of the Yangtze Block: New constraints from Hf isotopes and Fe/Mn ratios. Chinese Sci Bull 50, 2481-6. Li, Z. X., Li, X. H., 2007. Formation of the 1300-km-wide intracontinental orogen and postorogenic magmatic province in Mesozoic South China: A flat-slab subduction model. Geology 35, 179-82. Liang, H. Y., Campbell, I. H., Allen, C., Sun, W. D., Liu, C. Q., Yu, H. X., Xie, Y. W.,Zhang, Y.

ACCEPTED MANUSCRIPT Q., 2006. Zircon Ce4+/Ce3+ ratios and ages for Yulong ore-bearing porphyries in eastern Tibet. Miner Deposita 41, 152-9.

IP

T

Liang, H. Y., Campbell, I. H., Allen, C. M., Sun, W. D., Yu, H. X., Xie, Y. W.,Zhang, Y. Q.,

SC R

2007. The age of the potassic alkaline igneous rocks along the Ailao Shan-Red River shear zone: Implications for the onset age of left-lateral shearing. J Geol 115, 231-42. Liang, H. Y., Sun, W. D., Su, W. C., Zartman, R. E., 2009. Porphyry Copper-Gold

NU

Mineralization at Yulong, China, Promoted by Decreasing Redox Potential during

MA

Magnetite Alteration. Econ Geol 104, 587-96.

Liu, H. Q., Yang, S. Y., Zhang, X. L., 1985. Preliminary study on the genesis of the

D

Dabaoshan polymetallic deposit in the northern Guangdon province. Acta Geological

TE

Sinica, 48-61(in Chinese with English abstract).

CE P

Lu, Y. J., Loucks, R. R., Fiorentini, M. L., Yang, Z. M., and Hou, Z. Q., 2015. Fluid flux melting generated postcollisional high Sr/Y copper ore-forming water-rich magmas in

AC

Tibet. Geology 43, 583-586.Ludwig, K. R., 2003. ISOPLOT 3: a geochronological toolkit for Microsoft excel. Berkeley Geochronology Centre Special Publication 4, 74 pp. Ma, Z. D., Chen, Y. J., 2000. Geochemical discussion on Paleo-Mesoproteroxoic basement crust of Yangtze and Cathaysia craton in southern China: using trace elements as tracers. Geochimica 29, 525-32. Mitchell, A. H., 1973. Metallogenic Belts and Angle of Dip of Benioff Zones. Nature-Phys Sci 245, 49-52. Mungall, J. E., 2002. Roasting the mantle: Slab melting and the genesis of major Au and Au-rich Cu deposits. Geology 30, 915-8.

ACCEPTED MANUSCRIPT Pearce, J. A., Harris, N. B. W., Tindle, A. G., 1984. Trace-Element Discrimination Diagrams for the Tectonic Interpretation of Granitic-Rocks. J Petrol 25, 956-83.

IP

T

Pearce, N. J. G., Perkins, W. T., Westgate, J. A., Gorton, M. P., Jackson, S. E., Neal, C.

SC R

R.,Chenery, S. P., 1997. A compilation of new and published major and trace element data for NIST SRM 610 and NIST SRM 612 glass reference materials. Geostandard Newslett 21, 115-44.

NU

Qi, L., Hu, J., Gregoire, D. C., 2000. Determination of trace elements in granites by

MA

inductively coupled plasma mass spectrometry. Talanta 51, 501-13. Qu, H. Y., Chen, M. H., Yang, F. C., Gao, Z. H., Wang, Y. W., Zhao, H. J.,Yu, Z. F., 2014.

D

Metallogenic chronology of the stratiform Cu orebody in the Dabaoshan Cu polymetallic

TE

deposit, northern Guangdong Province and its geological significance. Acta Petrol Sin 30,

CE P

152-62 (in Chinese with English abstract). Qu, X. M., Hou, Z. Q., Zaw, K., Li, Y. G., 2007. Characteristics and genesis of Gangdese

AC

porphyry copper deposits in the southern Tibetan Plateau: Preliminary geochemical and geochronological results. Ore Geol Rev 31, 205-23. Richards, J. P., 2003. Tectono-magmatic precursors for porphyry Cu-(Mo-Au) deposit formation. Econ Geol Bull Soc 98, 1515-33. Richards, J. P., 2009a. Post-subduction porphyry and epithermal Au deposits. Geochim Cosmochim Ac 73, A1098-A. Richards, J. P., 2009b. Postsubduction porphyry Cu-Au and epithermal Au deposits: Products of remelting of subduction-modified lithosphere. Geology 37, 247-50. Rudnick, R. L., Fountain, D. M., 1995. Nature and Composition of the Continental-Crust - a

ACCEPTED MANUSCRIPT Lower Crustal Perspective. Rev Geophys 33, 267-309. Scherer, E., Munker, C., Mezger, K., 2001. Calibration of the lutetium-hafnium clock. Science

IP

T

293, 683-7.

SC R

Sillitoe, R. H., 1972. Plate Tectonic Model for Origin of Porphyry Copper Deposits. Econ Geol 67, 184-&.

Sillitoe, R. H., 2010. Porphyry Copper Systems. Econ Geol 105, 3-41.

NU

Stepanov, A. S., Hermann, J., Rubatto, D., Rapp, R. P., 2012. Experimental study of

MA

monazite/melt partitioning with implications for the REE, Th and U geochemistry of crustal rocks. Chem Geol 300, 200-20.

D

Stern, C. R., Funk, J. A., Skewes, M. A., Arevalo, A., 2007. Magmatic anhydrite in plutonic

TE

rocks at the El Teniente Cu-Mo deposit chile, and the role of sulfur- and copper-rich

CE P

magmas in its formation. Econ Geol 102, 1335-44. Sun, T., Zhou, X. M., Chen, P. R., Li, H. M., Zhou, H. Y., Wang, Z. C.,Shen, W. Z., 2005.

AC

Strongly peraluminous granites of mesozoic in Eastern Nanling Range, Southern China: Petrogenesis and implications for tectonics. Sci China Ser D 48, 165-74. Sun, W. D., Ding, X., Hu, Y. H., Li, X. H., 2007. The golden transformation of the Cretaceous plate subduction in the west Pacific. Earth Planet Sc Lett 262, 533-42. Sun, W. D., Huang, R. F., Li, H., Hu, Y. B., Zhang, C. C., Sun, S. J., Zhang, L. P., Ding, X., Li, C. Y., Zartman, R. E.,Ling, M. X., 2015. Porphyry deposits and oxidized magmas. Ore Geol Rev 65, 97-131. Sun, W. D., Li, S. G., Chen, Y. D., Li, Y. J., 2002. Timing of synorogenic granitoids in the South Qinling, central China: Constraints on the evolution of the Qinling-Dabie orogenic

ACCEPTED MANUSCRIPT belt. J Geol 110, 457-68. Sun, W. D., Liang, H. Y., Ling, M. X., Zhan, M. Z., Ding, X., Zhang, H., Yang, X. Y., Li, Y. L.,

IP

T

Ireland, T. R., Wei, Q. R.,Fan, W. M., 2013. The link between reduced porphyry copper

SC R

deposits and oxidized magmas. Geochim Cosmochim Ac 103, 263-75. Sun, W. D., Ling, M. X., Chung, S. L., Ding, X., Yang, X. Y., Liang, H. Y., Fan, W. M., Goldfarb, R., Yin, Q. Z., 2012a. Geochemical Constraints on Adakites of Different

NU

Origins and Copper Mineralization. J Geol 120, 105-20.

MA

Sun, W. D., Ling, M. X., Yang, X. Y., Fan, W. M., Ding, X., Liang, H. Y., 2010. Ridge subduction and porphyry copper-gold mineralization: An overview. Sci China Earth Sci

D

53, 475-84.

TE

Sun, W. D., Yang, X. Y., Fan, W. M., Wu, F. Y., 2012b. Mesozoic large scale magmatism and

CE P

mineralization in South China: Preface. Lithos 150, 1-5. Taylor, S. R., McLennan, S. M., The continental crust: its compostiion and evolution. Oxford:

AC

Blackwell; 1985.

Tu, X. L., Zhang, H., Deng, W. F., Ling, M. X., Liang, H. Y., Y., L.,Sun, W. D., 2011. Application of RESOlution in-situ laser ablation ICP-MS in trace element analyses. Geochimica 40, 83-98. Wang, F. Y., Ling, M. X., Ding, X., Hu, Y. H., Zhou, J. B., Yang, X. Y., Liang, H. Y., Fan, W. M.,Sun, W. D., 2011a. Mesozoic large magmatic events and mineralization in SE China: oblique subduction of the Pacific plate. Int Geol Rev 53, 704-26. Wang, L., Hu, M. A., Yang, Z., Qu, W. J., Xia, J. L.,Chen, K. X., 2011b. U-Pb and Re-Os geochronology and geodynamic setting of the Dabaoshan polymetallic deposit, northern

ACCEPTED MANUSCRIPT Guangdong Province, South China. Ore Geol Rev 43, 40-9. Wang, L. K., Qin, M. T., Liu, S. X., Huang, Z. L., Li, F. C., 2001. The key factors controling

IP

T

the formation of Cu, Au deposits along the Wuchuan-Sihui fault zone and its implication

SC R

for ore predition. Beijing: Geological Publishing, 1-19 (in Chinese with English abstract).

Wang, Q., Xu, J. F., Jian, P., Bao, Z. W., Zhao, Z. H., Li, C. F., Xiong, X. L.,Ma, J. L., 2006.

NU

Petrogenesis of adakitic porphyries in an extensional tectonic setting, dexing, South

MA

China: Implications for the genesis of porphyry copper mineralization. J Petrol 47, 119-44.

D

Wang, Y. J., Fan, W. M., Guo, F., Li, H. M., Liang, X. Q., 2002. U-Pb dating of early

TE

Mesozoic granodioritic intrusions in southeastern Hunan Province, South China and its

CE P

petrogenetic implications. Sci China Ser D 45, 280-8. Watson, E. B., and Harrison, T. M.., 1983. Zircon saturation revisited: temperature and

AC

composition effects in a variety of crustal magma types. Earth and Planetary Sci Lett, 64 (2), 295-304

Weill, D. F., and Drake, M. J., 1973. Europium anomaly in plagioclase feldspar: experimental results and semiquantitative model. Science, 180, 1059-1060. Winchester, J. A., Floyd, P. A., 1977. Geochemical Discrimination of Different Magma Series and Their Differentiation Products Using Immobile Elements. Chem Geol 20, 325-43. Wu, F. Y., Yang, Y. H., Xie, L. W., Yang, J. H.,Xu, P., 2006. Hf isotopic compositions of the standard zircons and baddeleyites used in U-Pb geochronology. Chem Geol 234, 105-26. Wu, J., Wang, G. Q., Liang, H. Y., Huang, W. T., Lin, S. P., Zou, Y. Q., Sun, W. D.,Wang, Y.

ACCEPTED MANUSCRIPT W., 2014. Indentification of Caledonian volcanic rock in the Dabaoshan ore-field in northern Guangdong Province and its geological implication. Acta Petrol Sin 30, 1145-54

IP

T

(in Chinese with English abstract).

SC R

Xiao, Y. L., Sun, W. D., Hoefs, J., Simon, K., Zhang, Z. M., Li, S. G., Hofmann, A. W., 2006. Making continental crust through slab melting: Constraints from niobium-tantalum fractionation in UHP metamorphic rutile. Geochim Cosmochim Ac 70, 4770-82.

NU

Xu, J. F., Shinjo, R., Defant, M. J., Wang, Q., Rapp, R. P., 2002. Origin of Mesozoic adakitic

MA

intrusive rocks in the Ningzhen area of east China: Partial melting of delaminated lower continental crust? Geology 30, 1111-4.

D

Xu, Y.H., Wang, C.Y., Zhao, T.P. 2016. Using detrital zircons from river sands to constrain

TE

major tectono-thermal events of the Cathaysia Block, SE China. Journal of Asian Earth

CE P

and Sciences 124, 1-13.

Xu, Y. J., 2013. Genetic types and resource potential evaluation of molybdenuym deposits in

AC

Guangdong province. Resources Survey &Environment 34, 178-185. Xu, X. S., O'Reilly, S. Y., Griffin, W. L., Wang, X. L., Pearson, N. J.,He, Z. Y., 2007. The crust of Cathaysia: Age, assembly and reworking of two terranes. Precambrian Res 158, 51-78. Zhang, H., Ling, M. X., Liu, Y. L., Tu, X. L., Wang, F. Y., Li, C. Y., Liang, H. Y., Yang, X. Y., Arndt, N. T.,Sun, W. D., 2013. High Oxygen Fugacity and Slab Melting Linked to Cu Mineralization: Evidence from Dexing Porphyry Copper Deposits, Southeastern China. J Geol 121, 289-305. Zheng, J. Y., 1996. Characteristics of the north section of the Wuchuan-Sihui fault and its

ACCEPTED MANUSCRIPT relation to metallogenesis. Uranium Geology 12, 265-275 (in Chinese with English abstract).

deposits

in

South

China:

A review.

Ore

Geology

Reviews,

SC R

molybdenum

IP

T

Zhong, J., Chen, Y. J., Pirajno, F., 2016. Geology, geochemistry and tectonic settings of the

http://dx.doi.org/10.1016/j.oregeorev.2016.04.012.

Zhong, L. F., Li, J., Peng, T. P., Xia, B., Liu, L. W., 2013. Zircon U-Pb geochronology and

NU

Sr-Nd-Hf isotopic compositions of the Yuanzhuding granitoid porphyry within the

MA

Shi-Hang Zone, South China: Petrogenesis and implications for Cu-Mo mineralization. Lithos 177, 402-15.

D

Zhong, L. F., Liu, L. W., Xia, B., Li, J., Lin, X. G., Xu, L. F.,Lin, L. Z., 2010. Re-Os

TE

Geochronology of Molybdenite from Yuanzhuding Porphyry Cu-Mo Deposit in South

CE P

China. Resour Geol 60, 389-96.

Zhou, X. M., Sun, T., Shen, W. Z., Shu, L. S., Niu, Y. L., 2006. Petrogenesis of Mesozoic

AC

granitoids and volcanic rocks in South China: A response to tectonic evolution. Episodes 29, 26-33.

Zhou, X. Y., Yu, J. H., Wang, L. J., Shen, L. W.,Zhang, C. H., 2015. Compositions and formation of the basement metamorphic rocks in Yunkai terrane, western Guangdong Province, South China. Acta Petrol Sin 31, 855-82 (in Chinese with English abstract). Zhu, B., Jiang, S. Y., Ding, X., Jiang, Y. H., Ni, P., Gu, L. X., 2008. Hydrothermal alteration and petrogenesis of granites in the Yongping copper deposit, Jiangxi Province: Constraints from mineral chemistry, element geochemistry, and Sr-Nd-Hf isotopes. Acta Petrol Sin 24, 1900-16 (in Chinese with English abstract).

ACCEPTED MANUSCRIPT Table 1 Zirocn U-Th-Pb isotope data of the Dabaoshan monzogranite porphyry, granite porphyry and the Chuandu porphyritic monzogranite Dabaoshan granite porphyry 206

-03 5802-70 -04 5802-70 -05 5802-70 -06 5802-70 -07 5802-70 -08 5802-70 -09 5802-70 -10 5802-70 -11 5802-70 -12 5802-70 -13 5802-70 -14 5802-70 -15 5802-70 -16 5802-70 -17 5802-70 -18 5802-70

52.8

0.0281

0.000

0.0391

0.048

8

4

95

8

52

194

0.2

0.0256

0.000

0.0129

0.047

0

5

3

48

9

57

205

0.1

0.0251

0.000

0.0121

0

9

5

41

0.9

0.0709

0.001

9

2

69

0.5

0.0338

6

0

1.4

0.1400

2

2

0.9 1

160

8.00

195

27.8

143

14.3

442

149

248

27.3 43.5

0.044

1

67

0.001

0.0266

0.052

08

7

81

0.002

1.2626

0.096

82

1

84

0.0245

0.000

0.0096

0.048

7

39

3

75

1.0

0.4457

0.007

9.1257

0.492

5

9

10

7

72 0.056

1

1

56

7

90

0.3

0.0297

0.000

0.0138

0.045

0

2

64

7

64

161

0.1

0.0268

0.000

0.0118

0.045

3

8

4

57

1

07

0.5

0.0769

0.001

0.0365

0.052

3

3

50

3

55

0.6

0.0261

0.000

0.0421

0.051

2

8

91

7

91

0.1

0.0269

0.000

0.0121

0.051

9

1

47

8

09

145

0.0

0.0368

0.000

0.0162

0.050

5

6

6

67

1

41

173

0.2

0.0273

0.000

0.0119

0.052

1

6

8

49

4

95

0.2

0.0340

0.001

0.0294

0.051

5

8

06

6

55

196

0.2

0.0257

0.000

0.0104

0.050

0

9

1

36

0

09

527

0.1

0.0384

0.000

0.2494

0.023

856

25.1

924

20.2

0.5273

0.0176

108

52.4

51

0.000

3.30

8.10

8

0.0255

542

48.4

0.050

0.8

151

46.7

52.4

U

0.9

14.2

4.90

5

207

±1σ

240

Pb/20

6

Pb

SC R

51.1

U

Pb/23

T

117

U

8

207

±1σ

IP

4.10

Pb/23

NU

5802-70

m)

206

MA

-02

m)

Th/

D

5802-70

(pp

TE

-01

(pp

Pb*/2

CE P

5802-70

U

AC

Spots

Pb

0.01009 0.00361 0.00345 0.05389 0.00533 0.06412 0.00299 0.14760 0.00571 0.00350 0.00310 0.00339 0.01179 0.00332 0.00317 0.00292 0.00629 0.00297 0.04779

±1σ

38

±1

Age(Ma

σ

U

) 0.196 90 0.170 54 0.178 16 0.004 78 0.254 19 0.004 67 0.164 26 0.007 76 0.191 86 0.183 76 0.165 11 0.552 99 0.179 38 0.188 61 0.255 70 0.202 01 0.235 97 0.178 79 0.004

Concorda nce

178.9

6.0

98%

163.2

3.0

97%

160.1

2.6

96%

441.7 214.3 844.8 156.5 2376.5

10. 1 6.8 15. 9 2.5 31. 7

97% 92% 98% 98% 98%

162.4

3.5

90%

188.8

4.0

90%

170.7

3.6

90%

477.7

9.0

93%

166.6

5.7

99%

171.2

3.0

97%

233.3

4.2

99%

174.2

3.1

92%

216.0

6.6

99%

163.7

2.2

97%

242.9

5.3

92%

ACCEPTED MANUSCRIPT

5802-70 5802-70 5802-70 5802-70 -25 5802-70 -26 5802-70 -27 5802-70 -28

0.000

0.0155

0.051

5

1

66

3

08

0.6

0.0971

0.001

1.0151

0.084

0

1

99

1

74

112

0.1

0.0297

0.000

0.0126

0.048

3

6

5

43

8

28

104

0.2

0.0263

0.000

0.0121

0.046

0

4

7

48

9

22

145

0.2

0.0257

0.000

0.0122

0.046

4

4

9

57

3

97

0.7

0.0737

0.002

0.0763

0.064

9

7

35

1

59

0.1

0.0252

0.000

7

5

44

0.7

0.0278

0.000

6

4

0.3

0.0254

5

7

25.8

243

38.2

-24

0.0290

670

28.3

-23

0.3

20.1

34.2

-22

39

9.40

106

21.3

761

5.20

148

15.2

513

69 0.00404 0.07454

0.0097

0.046

0

80

0.0225

0.053

68

7

87

0.000

0.0092

0.048

41

8

25

0.203

184.4

64 0.006 03

597.4

0.199

T

-21

8

0.00324

IP

5802-70

85

0.00319

SC R

-20

0

NU

5802-70

8

MA

-19

0.00347 0.00803 0.00276 0.00621 0.00255

34

0.170 52 0.167 01 0.628 0.166 01 0.201 03 0.169 51

11. 7

97% 82%

189.0

2.7

97%

167.8

3.0

95%

164.1

3.6

95%

458.8

45

4.1

14. 1

92%

160.7

2.8

96%

177.0

4.3

95%

162.1

2.6

98%

Pb

U

(ppm)

(ppm)

6001-63-1

12.0

350

6001-63-2

43.3

1682

6001-63-3

22.9

789

6001-63-4

25.9

6001-63-5

D

Dabaoshan monzogranite porphyry

1.00 0.15

±1σ

±1σ

0.02586

0.00050

0.01412

0.05469

0.00368

0.20045

164.6

3

0.02343

0.00033

0.00693

0.04758

0.00220

0.15617

149.3

2

0.22

0.02707

0.00051

0.01035

0.04821

0.00277

0.18213

172.2

3

933

0.20

0.02540

0.00041

0.00781

0.04882

0.00205

0.17328

161.7

2

8.00

241

0.46

0.02730

0.00058

0.01510

0.05344

0.00424

0.19870

173.6

3

6001-63-6

21.8

158

0.38

0.11596

0.00179

0.91543

0.04674

0.05732

0.00291

707.3

1

6001-63-7

13.2

477

0.32

0.02359

0.00040

0.00965

0.05176

0.00312

0.16730

150.3

2

6001-63-8

10.6

373

0.30

0.02368

0.00050

0.01029

0.04610

0.00327

0.15235

150.9

3

6001-63-9

29.9

1034

0.25

0.02684

0.00060

0.01687

0.05287

0.00454

0.19532

170.7

3

6001-63-10

13.4

446

0.43

0.02615

0.00042

0.00984

0.04684

0.00276

0.16710

166.4

2

6001-63-11

35.1

1259

0.21

0.02627

0.00041

0.01247

0.04997

0.00360

0.18012

167.1

2

6001-63-12

23.2

816

0.20

0.02589

0.00035

0.00790

0.04794

0.00224

0.17136

164.8

2

6001-63-13

126

710

0.51

0.14830

0.00234

1.34111

0.04856

0.06517

0.00231

891.4

1

6001-63-14

59.1

2120

0.28

0.02552

0.00040

0.01140

0.05423

0.00338

0.19026

162.4

2

6001-63-15

18.1

333

0.33

0.04625

0.00159

0.03791

0.05544

0.00660

0.35414

291.4

9

6001-63-16

36.8

307

0.37

0.10237

0.00215

0.91397

0.04927

0.06465

0.00353

628.3

1

6001-63-17

16.1

478

0.63

0.02766

0.00057

0.01119

0.04991

0.00303

0.19002

175.9

3

6001-63-18

36.6

1324

0.21

0.02589

0.00047

0.01269

0.04638

0.00339

0.16729

164.8

3

6001-63-19

58.5

475

0.54

0.10248

0.00127

0.86268

0.04612

0.06054

0.00326

629.0

7

6001-63-20

40.9

1485

0.12

0.02689

0.00046

0.01103

0.04607

0.00284

0.17245

171.1

2

6001-63-21

9.60

335

0.14

0.02625

0.00048

0.01295

0.05332

0.00349

0.19392

167.0

3

6001-63-22

18.4

634

0.31

0.02675

0.00060

0.01913

0.05442

0.00519

0.20060

170.2

3

6001-63-23

27.7

978

0.19

0.02529

0.00039

0.00954

0.05064

0.00268

0.17887

161.0

2

CE P

AC

238

Pb/ U

235

Pb/ U

206

Pb*/238U

207

TE

Th/U

206 207

Spots

206

Pb/ Pb

±1σ

(Age,Ma)

±

ACCEPTED MANUSCRIPT 13.5

265

0.38

0.04134

0.00080

0.01954

0.05666

0.00355

0.32483

261.1

4

6001-63-25

33.8

1277

0.18

0.02602

0.00055

0.01290

0.05048

0.00343

0.18401

165.6

3

6001-63-26

53.9

1998

0.27

0.02578

0.00056

0.01179

0.05028

0.00315

0.18144

164.1

3

6001-63-27

21.4

467

0.35

0.04009

0.00082

0.02719

0.05698

0.00492

0.31735

253.4

5

6001-63-28

9.80

358

0.30

0.02576

0.00064

0.01604

0.05446

0.00491

0.18923

164.0

4

6001-63-29

28.1

1055

0.22

0.02577

0.00051

0.01156

0.04557

0.00325

0.16080

164.0

3

Pb

U

(ppm)

(ppm)

CD1-1-01

27.3

CD1-1-02

207

Pb/235U

206

206

1028

0.23

0.02449

0.00034

0.15275

0.00656

0.04513

0.00195

156.0

2

27.3

1017

0.23

0.02514

0.00033

0.15739

0.00649

0.04515

0.00185

160.1

2

CD1-1-03

46.5

1326

0.17

0.03403

0.00077

0.23500

0.00941

0.04962

0.00170

215.7

4

CD1-1-04

27.6

996

0.21

0.02568

0.00028

0.17111

0.00681

0.04809

0.00193

163.4

1

CD1-1-05

19.1

699

0.19

0.02588

CD1-1-06

22.8

839

0.17

0.02627

CD1-1-07

34.1

1230

0.21

0.02594

CD1-1-08

32.0

1089

0.25

0.02710

CD1-1-09

3.10

91.4

0.53

CD1-1-10

35.6

1380

CD1-1-11

24.2

CD1-1-12

Pb/206Pb

±1σ

±1σ

(Age,Ma)

±

0.00032

0.17672

0.00773

0.04931

0.00218

164.7

2

0.00039

0.18828

0.00837

0.05147

0.00212

167.2

2

0.00029

0.17337

0.00658

0.04839

0.00186

165.1

1

0.00032

0.18998

0.00670

0.05080

0.00178

172.4

2

0.02860

0.00080

0.28181

0.02349

0.07992

0.00777

181.8

5

0.22

0.02426

0.00033

0.16010

0.00570

0.04784

0.00164

154.5

2

875

0.22

0.02573

0.00032

0.16768

0.00696

0.04740

0.00200

163.8

2

39.0

1480

0.24

0.02479

0.00035

0.16962

0.00653

0.04956

0.00183

157.9

2

CD1-1-13

41.9

1265

0.13

CD1-1-14

24.3

898

CD1-1-15

24.4

903

CD1-1-16

21.2

CD1-1-17

27.7

CD1-1-18

20.4

CD1-1-19

31.5

CD1-1-20

40.5

CD1-1-21

0.00085

0.22637

0.00922

0.05014

0.00162

207.0

5

0.02564

0.00032

0.16028

0.00625

0.04551

0.00183

163.2

2

0.21

0.02524

0.00033

0.18201

0.00737

0.05233

0.00210

160.7

2

TE

0.03264

0.20

CE P

D

MA

NU

SC R

±1σ

207

Pb*/238U

Th/U

Spots

Pb/238U

IP

Chuandu porphyritic monzogranite

T

6001-63-24

0.19

0.02632

0.00033

0.16109

0.00700

0.04425

0.00190

167.5

2

982

0.25

0.02568

0.00031

0.17224

0.00630

0.04852

0.00177

163.4

1

733

0.28

0.02548

0.00034

0.15792

0.00768

0.04482

0.00212

162.2

2

1068

0.23

0.02797

0.00059

0.18703

0.00743

0.04853

0.00179

177.8

3

1542

0.23

0.02422

0.00034

0.15819

0.00583

0.04725

0.00172

154.2

2

24.9

891

0.24

0.02575

0.00042

0.17761

0.00829

0.05000

0.00229

163.9

2

CD1-1-22

20.5

747

0.18

0.02515

0.00032

0.17157

0.00751

0.04943

0.00219

160.1

2

CD1-1-23

23.4

859

0.18

0.02533

0.00031

0.15648

0.00647

0.04448

0.00180

161.2

1

CD1-1-24

14.3

516

0.16

0.02572

0.00032

0.15788

0.00880

0.04445

0.00254

163.7

2

CD1-1-25

24.5

521

0.37

0.04237

0.00088

0.27592

0.01393

0.04714

0.00230

267.5

5

AC

750

le 2 Zircon Hf isotopic data of the Dabaoshan porphyry Sample

176

Yb/177Hf

2σ

176

Lu/177Hf

2σ

176

Hf/177Hf

2σ

εHf(t)

TDM2

5802-70-1

0.058140

0.00089

0.001473

0.000025

0.282418

0.000013

-9.04

1782

5802-70-2

0.059857

0.00122

0.001565

0.000025

0.282391

0.000013

-9.99

1842

5802-70-3

0.062942

0.00063

0.001621

0.000017

0.282412

0.000009

-9.26

1796

5802-70-7

0.032617

0.00009

0.000877

0.000002

0.282449

0.000008

-7.86

1708

5802-70-9

0.036651

0.00034

0.000990

0.000009

0.282422

0.000012

-8.85

1770

5802-70-10

0.047665

0.00025

0.001305

0.000011

0.282461

0.000011

-7.51

1686

5802-70-11

0.049443

0.00010

0.001246

0.000002

0.282431

0.000012

-8.56

1752

ACCEPTED MANUSCRIPT 0.063974

0.00111

0.001626

0.000029

0.282459

0.000009

-7.62

1693

5802-70-14

0.056560

0.00061

0.001514

0.000014

0.282339

0.000012

-11.83

1958

5802-70-16

0.037580

0.00013

0.000968

0.000002

0.282408

0.000012

-9.35

1802

5802-70-18

0.077996

0.00035

0.001991

0.000011

0.282302

0.000009

-13.21

2045

5802-70-20

0.078548

0.00083

0.001984

0.000017

0.282444

0.000010

-8.18

1728

5802-70-22

0.044687

0.00028

0.001171

0.000008

0.282408

0.000008

-9.35

1802

5802-70-23

0.017955

0.00018

0.000454

0.000003

0.282452

0.000009

-7.71

1699

5802-70-24

0.063591

0.00050

0.001635

0.000014

0.282379

0.000011

-10.44

1871

AC

CE P

TE

D

MA

NU

SC R

IP

T

5802-70-13

ACCEPTED MANUSCRIPT Table 3 Whole-rock major and trace element data of the Dabaoshan porphyry Sample

Dabaoshan porphyry 5803-21

5803-82

5804-566

5810-330

5804-100

5002-101

5805-297

5805-434

5810-342

Major elements (wt%) 72.11

68.44

76.32

65.06

70.88

69.49

64.42

71.34

68.37

TiO2

0.39

0.37

0.22

0.36

0.37

0.26

0.48

0.26

0.37

Al2O3

13.96

14.59

10.77

15.33

14.64

14.37

14.48

13.27

14.55

Fe2O3

4.11

5.69

0.60

1.78

4.16

1.22

4.11

2.01

5.32

MnO

0.02

0.01

0.03

0.03

0.07

0.12

0.07

0.15

0.05

MgO

0.76

0.75

0.55

1.23

0.96

0.76

2.61

0.78

0.82

CaO

0.04

0.11

1.65

2.77

0.06

2.11

2.00

1.84

0.40

K 2O

4.55

4.77

7.10

9.07

4.81

7.98

5.98

6.68

4.77

Na2O

0.00

0.01

0.11

0.15

P2O5

0.02

0.08

0.08

0.16

L.O.I

3.45

4.60

1.99

3.44

Total

99.40

99.41

99.41

99.38

IP

NU

SC R

0.31

0.26

0.60

0.42

0.77

0.02

0.12

0.21

0.13

0.16

3.22

2.70

4.80

2.92

4.22

99.51

99.40

99.74

99.79

99.79

MA

Trace elements (ppm)

T

SiO2

6.12

6.74

14.4

11.5

4.28

7.82

10.1

3.86

8.31

V

46.1

54.4

99.9

75.9

22.7

44.4

71.0

27.6

107

Cr

297

181

295

204

15.1

34.1

60.0

41.9

43.4

Co

4.00

9.28

7.47

9.88

1.54

4.26

8.72

5.11

28.9

Ni

16.8

12.5

38.3

17.6

5.20

6.42

9.26

4.75

8.48

Ga

11.1

15.4

19.5

17.4

15.7

18.7

16.9

12.5

16.0

Rb

145

191

353

160

285

209

262

229

200

Sr

10.8

9.74

257

426

205

9.66

134

183

13.8

Y

9.20

13.5

27.1

16.4

15.5

13.0

19.8

9.71

19.6

Zr

145

197

130

101

145

177

173

115

187

Nb

12.0

14.8

14.6

13.7

17.2

13.3

12.5

9.1

13.6

Cs

1.22

1.99

15.4

5.37

9.91

3.23

11.8

8.02

2.40

Ba

577

658

1101

691

1150

482

1982

2152

603

Hf

3.91

5.33

3.65

3.03

4.11

4.93

4.79

3.05

5.22

Ta

1.02

1.35

1.21

1.44

1.71

1.25

1.02

0.54

1.14

Pb

1.73

0.90

16.5

26.6

15.8

2.84

7.76

15.1

3.74

Th

11.6

13.3

19.6

28.4

14.0

13.6

13.7

5.68

14.7

U

1.39

2.50

5.13

8.61

3.82

1.86

3.14

1.60

2.83

La

33.5

29.7

52.7

29.1

37.2

41.2

50.0

21.5

53.5

Ce

63.0

58.8

99.1

56.5

71.7

76.9

95.1

41.5

98.1

Pr

7.08

6.83

11.5

6.81

7.68

8.55

10.9

4.79

11.0

Nd

25.1

24.2

43.4

25.3

26.4

30.1

39.5

17.4

38.9

Sm

3.76

3.98

7.64

4.53

4.27

4.85

6.51

3.01

6.25

Eu

0.61

0.69

1.46

1.10

1.03

0.84

1.49

0.93

1.13

Gd

2.34

2.69

6.10

3.67

3.61

3.73

5.29

2.44

5.05

Tb

0.35

0.45

0.95

0.53

0.50

0.48

0.72

0.35

0.67

Dy

1.86

2.62

5.44

3.07

2.74

2.55

3.90

1.94

3.73

TE

CE P

AC

D

Sc

ACCEPTED MANUSCRIPT 0.38

0.55

1.13

0.63

0.54

0.51

0.77

0.37

0.75

Er

1.04

1.49

2.99

1.71

1.44

1.37

2.03

0.97

2.04

Tm

0.16

0.23

0.44

0.27

0.21

0.21

0.30

0.14

0.31

Yb

1.10

1.52

2.89

1.81

1.34

1.40

1.92

0.89

2.04

Lu

0.18

0.23

0.45

0.28

0.20

0.22

0.29

0.14

0.32

Th/U

8.38

5.34

3.82

3.30

3.67

7.32

4.38

3.56

5.21

Nb/Ta

11.8

11.0

12.0

9.56

10.1

10.6

12.2

16.8

11.9

EuN/Eu*

0.58

0.61

0.63

0.80

0.78

0.58

0.75

1.02

0.60

(La/Yb)N

20.8

13.3

12.0

10.9

18.9

20.0

17.7

16.4

17.8

738

842

808

771

854

772

801

TE

D

MA

NU

876

CE P

848

AC

T(ºC)

IP

SC R

Whole rock Zr saturation tempuature

T

Ho

ACCEPTED MANUSCRIPT Table 4 Sr-Nd isotopic data of the Dabaoshan porphyry Sm(ppm)

Nd(ppm)

147

143

2ơ

Ɛ Nd(t)

TDM(Ga)

Rb(ppm)

Sr(ppm)

87

5803-21

3.76

25.1

0.0907

0.512104

0.000003

-8.20

1.30

145

10.8

3

5803-82

3.98

24.2

0.0995

0.512154

0.000001

-7.40

1.33

190

9.74

5

5804-566

7.64

43.4

0.1065

0.512190

0.000005

-6.84

1.37

352

257

3

5810-330

4.53

25.3

0.1080

0.512157

0.000006

-7.52

1.43

159

425

1

IP

Nd/144Nd

AC

CE P

TE

D

MA

NU

SC R

Sm/144Nd

T

Sample

AC

CE P

TE

D

MA

NU

SC R

IP

T

ACCEPTED MANUSCRIPT

Graphical abstract

AC

CE P

TE

D

MA

NU

SC R

IP

T

ACCEPTED MANUSCRIPT

AC

CE P

TE

D

MA

NU

SC R

IP

T

ACCEPTED MANUSCRIPT

AC

CE P

TE

D

MA

NU

SC R

IP

T

ACCEPTED MANUSCRIPT

AC

CE P

TE

D

MA

NU

SC R

IP

T

ACCEPTED MANUSCRIPT

AC

CE P

TE

D

MA

NU

SC R

IP

T

ACCEPTED MANUSCRIPT

AC

CE P

TE

D

MA

NU

SC R

IP

T

ACCEPTED MANUSCRIPT

AC

CE P

TE

D

MA

NU

SC R

IP

T

ACCEPTED MANUSCRIPT

AC

CE P

TE

D

MA

NU

SC R

IP

T

ACCEPTED MANUSCRIPT

AC

CE P

TE

D

MA

NU

SC R

IP

T

ACCEPTED MANUSCRIPT

AC

CE P

TE

D

MA

NU

SC R

IP

T

ACCEPTED MANUSCRIPT

AC

Fig. 11

CE P

TE

D

MA

NU

SC R

IP

T

ACCEPTED MANUSCRIPT

ACCEPTED MANUSCRIPT Highlights

T

(1) The Dabaoshan porphyry Mo-W deposit was formed in the intracontinental environment and was triggered

IP

by the activities of Wuchuan-Sihui deep fault.

associated with Mo-W mineralization in the Dabaoshan deposit.

SC R

(2) There were two pulses of magmatic activities, at the age of 166.2~166.3Ma and ~162.1 Ma, respectively,

rocks without significant contributions from mantle.

NU

(3) The fertile magmas were derived from high temperature, high degree of partial melting of the Proterozoic

MA

(4) Metamorphic dehydration H2O-rich fluids should play a key role in the formation of high oxidized magmas

AC

CE P

TE

D

associated with porphyry Mo (±Cu-W) mineralization along deep fault zone in the interior of the continent.