Geology and geochronology of the Shijia gold deposit, Jiaodong Peninsula, China

Journal Pre-proofs Geology and geochronology of the Shijia gold deposit, Jiaodong Peninsula, China Li-Qiang Feng, Xue-Xiang Gu, Yong-Mei Zhang, Jia-Lin Wang, Zhan-Lin Ge, Yu He, Ying-Shuai Zhang PII: DOI: Reference:

S0169-1368(19)30685-7 https://doi.org/10.1016/j.oregeorev.2020.103432 OREGEO 103432

To appear in:

Ore Geology Reviews

Received Date: Revised Date: Accepted Date:

26 July 2019 26 January 2020 24 February 2020

Please cite this article as: L-Q. Feng, X-X. Gu, Y-M. Zhang, J-L. Wang, Z-L. Ge, Y. He, Y-S. Zhang, Geology and geochronology of the Shijia gold deposit, Jiaodong Peninsula, China, Ore Geology Reviews (2020), doi: https:// doi.org/10.1016/j.oregeorev.2020.103432

This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. 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.

© 2020 Published by Elsevier B.V.

Geology and geochronology of the Shijia gold deposit, Jiaodong Peninsula, China Li-Qiang Feng1, Xue-Xiang Gu1,2*, Yong-Mei Zhang1,2, Jia-Lin Wang2, Zhan-Lin Ge1, Yu He1, Ying-Shuai Zhang1 1 School of Earth Sciences and Resources, China University of Geosciences, Beijing 100083, China 2 State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences, Beijing 100083, China *Correspondence to: X.X. Gu, State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences, No. 29 Xueyuan Road, Beijing 100083, China. Email: [email protected]

Abstract The Shijia gold deposit, classified as a Linglong-type (quartz vein-type) gold deposit, is located in the north of Qixia-Penglai gold belt in the Jiaodong Peninsula. The orebodies predominantly occurring as quartz-sulfide veins are hosted in the Early Cretaceous Guojialing amphibole-bearing monzogranite and strictly controlled by NNE- to NE-striking high-angle faults. Hydrothermal minerals include K-feldspar, quartz, sericite, pyrite, sphalerite, galena, chalcopyrite, calcite and fluorite. Based on the mineralogical, textural and field cross-cutting relationships, the mineralization process can be divided into three stages: (Ⅰ) quartz-sericite-pyrite stage, (Ⅱ) quartzsulfide-gold stage and (Ⅲ) quartz-calcite-fluorite stage. Field investigation shows that the orebodies have undergone several times of deformation after their formation, resulting in the deformation and discontinuity of the orebodies. Early Cretaceous dykes, including granite pegmatite, lamprophyre, diabase and granite porphyry, are developed in the Shijia gold deposit. The crosscutting relationship between orebodies and various mafic-felsic dykes shows that their formation sequence is granite pegmatite, Au orebody, lamprophyre, diabase and granite porphyry. LA-ICP-MS zircon U-Pb dating shows that the emplacement ages of granite pegmatite, 1

lamprophyre, diabase, and granite porphyry are 129.7 ± 1.6 Ma, 129.3 ± 1.4 Ma, 128.3 ± 1.3 Ma and 120.0 ± 1.1 Ma, respectively. These dating results are consistent with the crosscutting phenomenon observed in the field, indicating that the mineralization time of the Shijia gold deposit is between 129.7 Ma and 129.3 Ma. The timing of gold mineralization at Shijia coincides with the large-scale thinning of the lithosphere in the North China Craton during the Early Cretaceous, indicating that the formation of the deposit is mainly controlled by extensional tectonics. Because the gold mineralization was predated the emplacement of lamprophyre and diabase dykes, there might be not a direct genetic relationship between the gold mineralization and the mafic dykes in the Shijia gold deposit. Keywords: LA-ICP-MS zircon U-Pb dating; geological characteristics; mineralization time; Shijia gold deposit; Shandong Province

1. Introduction The Jiaodong gold province, located in the Jiaodong Peninsula, east of the North China Craton (NCC), is one of the largest provinces of granitoid-hosted lode-gold deposits in the world (Qiu et al., 2002). More than 100 gold deposits with measured gold reserves exceeding 4000 t have been discovered in this province, making it become the most important Au producers in China (Yang et al., 2014a; Xue et al., 2018). The mineralization time of the gold deposits in Jiaodong has been extensively studied, but yet debated. Early studies emphasized that Precambrian metamorphic rocks played an important role in the formation of the Jiaodong gold deposits, and argued that the deposits were formed in Archean (Guo et al., 1951) and/or Proterozoic (Yu et al., 1987). However, considering that the gold deposits were closely associated with Mesozoic magmatic activities, many other researchers proposed that the mineralization occurred in the late Mesozoic during the Yanshanian orogeny (Yao et al., 1990; Li et al., 1993). The current common recognition is that the mineralization took place in the Early Cretaceous (Zhang et al., 2002a; Chen et al., 2004; Zhai et al., 2004; Yang et al., 2006; Li et al., 2015; Song et al., 2015, 2018a), and that the gold deposits found in different tectonic locations and host rocks in Jiaodong were formed 2

within a relatively short time period under the same tectonic setting (Zhai et al., 2004; Song et al., 2014, 2015; Fan et al., 2005, 2016). Previous studies show that the emplacement time of various types of dykes in Jiaodong ranges from 132 to 113 Ma (Guo et al., 2004; Liu et al., 2009; Ma et al., 2014, 2016; Li et al., 2010; Li et al., 2016; Li et al., 2018). Because this age range overlaps with the mineralization age of the Jiaodong gold deposits and the timing relationship between gold mineralization and dykes is readily discerned in the field, the relative timing of various dykes could be used to limit the gold mineralization age. The Shijia gold deposit, located in the north of the Qixia-Penglai gold belt of the Jiaodong Peninsula, is a medium-sized, granitoid-hosted, quartz vein-type gold deposit. Zircons in the gold-bearing quartz veins at Shijia are mainly captured zircons with features of magmatic zircon, and their age (132.2 ± 1.3 Ma, unpublished data) are consistent with those of the Guojialing granite (130~126 Ma, Wang et al., 1998), therefore, they cannot represent the mineralization age of the deposit. There are various types of mafic-felsic dykes in the Shijia gold deposit. These dykes show a clear crosscutting relationship with orebodies in space, which can be used to limit the timing of gold mineralization. In the present study, we described the geology of the Shijia gold deposit with an emphasis on the field relationship between the dykes and gold mineralization. The mineralization time of the Shijia gold deposit was limited using LA-ICP-MS zircon U-Pb isotopic geochronology of the related dykes. Combined with the geological evolution since Mesozoic in Jiaodong, we discussed the tectonic background for the formation of the gold deposit.

2. Regional geology The Jiaodong gold province is located in the Jiaobei Uplift on the southeastern margin of NCC, with the Jiaolai Basin in the south. On the west and east of the district are the Luxi Block and Su-Lu Ultrahigh Pressure Metamorphic (UHP) Belt, which are separated by the regional Tan-Lu Fault and Wulian-Yantai Fault, respectively. From west to east, the Jiaodong gold province can be divided into Zhaoyuan-Laizhou, Penglai-Qixia and Muping-Rushan gold belts (Qiu et al., 2002; Fan et al., 2016). The 3

Shijia gold deposit is located in the north of Penglai-Qixia gold belt (Fig. 1). The strata exposed near the Shijia gold deposit include the Neoarchaean Jiaodong Group, the Paleoproterozoic Fenzishan Group, the Neoproterozoic Penglai Group, and the Mesozoic Lower Cretaceous Laiyang and Qingshan Groups (Fig.2). The Jiaodong Group formed at 2.9 to 2.7 Ga (Jahn et al., 2008) is a medium- to high-grade metamorphic sequence composed mainly of amphibolite, biotite granulite, magnetite quartzite and amphibolite granulite. The Fenzishan Group discordantly overlies the Jiaodong Group, and is mainly composed of clastic rocks and carbonate that have undergone low amphibolite facies metamorphism. The age of the Fenzishan Group, determined by SHIRMP zircon U-Pb dating ranges from 1.9 to 2.1 Ga (Xie et al., 2014). The Penglai Group, formed later than 986 Ma (Chu et al., 2011) and unconformably overlying the Jiaodong and Fenzishan Groups, consists of a series of weakly metamorphosed sedimentary rocks, including phyllite, slate, quartzite and limestone. The Laiyang and the Qingshan Groups, occur in the Laiyang Basin and were both deposited in the Middle to Late Early Cretaceous, with the formation time 125 ± 0.6 Ma and 119 ± 1 Ma, respectively (Zhou et al., 2016). The fluvial-lacustrine clastic sedimentary rocks of the Laiyang Group mainly consist of lithic feldspar sandstone, clayey siltstone and conglomerate-bearing sandstone, locally with lenticular marl. The Qingshan Group unconformably overlies the Laiyang Group and is composed of volcanic sedimentary rocks, including tuff, andesite breccia and complex conglomerate. The regional tectonic framework is characterized by a series of predominantly NNE-trending faults with less commonly NE-, NW-, and nearly NS- and EW-trending faults (Fig. 2). The Huluxian fault is the largest fault adjacent to the Shijia gold deposit, about 25 km long, several to tens of meters wide, striking NNE and dipping 48° to 79° the southeast. In general, the NNE- to NE-trending faults have controlled the distribution of altered zones, auriferous quartz veins and dykes in the district. Magmatic rocks are widely distributed in the district, dominated by Neoarchean, Paleoproterozoic and Mesozoic intrusive rocks. Mesozoic mafic-felsic dykes are also well developed (Fig. 2). The Neoarchaean intrusions comprise fine-grained 4

metagabbro, fine-grained hornblende-bearing biotite dioritic gneiss and fine-grained biotite-bearing granodiorite. The Paleoproterozoic intrusive rocks include fine-grained metagabbro and fine-grained gneissic biotite monzogranite. Mesozoic magmatism in the district is typically represented by the Late Jurassic Linglong intrusion and the Early Cretaceous Guojialing intrusion. The Linglong intrusion, located to the east of the Huluxian fault, consists of medium- to coarse-grained monzogranite and weakly gneissic, fine-grained garnet-bearing monzogranite. The Guojialing intrusion occurs in the west of the Huluxian fault, and consists of medium- to coarse-grained amphibolite-bearing

diorite,

medium-

to

fine-grained

amphibole-bearing

monzogranite and biotite-bearing monzogranite. Mesozoic dykes have a diverse lithology, including granite pegmatite, lamprophyre, diabase and granite porphyry. Detailed isotopic geochronological studies show that the Linglong granite was emplaced at 160 to 150 Ma (Wang et al., 1998; Yang et al., 2012), the Guojialing granite intruded at 130 to 126 Ma (Wang et al., 1998), and the mafic-felsic dykes formed at 132 to 113 Ma (Guo et al., 2004; Liu et al., 2009；Ma et al., 2014, 2016; Li et al., 2010; Li et al., 2016; Li et al., 2018).

3. Geology of the Shijia gold deposit 3.1 Deposit geology The Shijia gold deposit is located in the Penglai City, Eastern Shandong Province, approximately 1 km northeast of the small town Daliuhang, at an elevation between 60 and 139 m above sea level. It is a medium-sized, granitoid-hosted quartz vein-type gold deposit, with an average grade of 6.74 g/t Au and the Au reserve of more than 10 t. Mesozoic granitic rocks cover the entire area of the deposit. The Guojialing amphibole-bearing monzogranite in the west and the Linglong garnet-bearing monzogranite in the east are separated by the NNE-trending Huluxian fault. Basic to felsic dykes including lamprophyre, diabase, granite pegmatite and granite porphyry are also developed in the district (Fig. 3a). A series of subsidiary, NNE-trending strike-slip faults are well developed and have controlled the occurrence of main orebodies. Nearly E-W-trending, small-scale strike-slip faults commonly cut and 5

dislocate orebodies. The orebodies are predominantly hosted in the Guojialing amphibole-bearing monzogranite and occur typically as auriferous quartz veins filling the NE-trending faults. Three largest ore veins (orebodies) in the deposit include No. 1, No. 326 and No. 334 veins (Fig. 3b, c) and their main characteristics are described as follows: The No. 1 vein is the largest orebody and located in the western part of the ore district, with a strike length of 1010 m, a maximum dip depth of 1030 m and an average thickness of 0.9 m. It strikes NNW 350° to NNE 25°, and dips from 61° to 89° to the east (Fig. 4a). Mineralization of the No. 1 vein is relatively continuous and accounts for about 48% of the total proven ore reserves, with Au grades ranging from 1.00 to 41.54 g/t and averaging 5.60 g/t. The No. 326 vein, accounting for approximately 29% of the ore reserves, is located in the mid-west of the district, about 100 to 200 m to the east of the No. 1 vein. It is divided into two sub-orebodies, i.e., the No. 326-2 and No. 326-3 (Fig 3b). The No. 326-2 orebody is more than 350 m long and 0.17 to 1.92 m wide and extends for about 910 m along its dip. The gold grade varies from 1.10 to 273.88 g/t, with an average of 6.60 g/t. The No. 326-3 orebody is more than 310 m long, with an average width of 0.75 m and an average gold grade of 8.62 g/t. The No. 326 vein as a whole strikes roughly south to north and dips from 57° to 90° (average 73°) to the east (Fig. 4b). Locally, several branch veins that intersect obliquely with the main vein are observed in the hanging and foot walls of the main vein, with strikes varying from NNW 352° to NE 64° (average NNE 20°) and eastward dip angles ranging from 22° to 89° (average 64°) (Fig. 4c). The No. 334 vein is approximately 50 to 200 m to the east of the No. 326 vein and consists of two orebodies of No. 334-1 and No. 334-2. The No. 334-1 orebody is 280 m long and extends for about 330 m along its dip, with a thickness of 0.19 to 2.02 m (average 0.77 m), and the gold grade of 1.20 to 60.00 g/t (average 10.78 g/t). The No. 334-2 orebody is about 250 m long and 0.19 to 2.02 m thick (average 0.78 m), with gold grade ranging from 1.00 to 72.20 g/t (average 7.72 g/t). The main vein strikes nearly S-N, and dips from 59° to 90° (72° on average) to the east (Fig. 4d). There are 6

some branch veins with a strike of NNE 13° to 32°, and dip 59° to 89°, intersecting with the main vein at an angle of about 30° (Fig. 4e). 3.2 Ore mineralogy Mineralization in the Shijia gold deposit occurs predominantly as fault- or fracture-filling auriferous quartz-sulfide veins with small amounts of disseminated ores in the altered wall rocks adjacent to main lodes (Fig. 5a). Ore minerals are mainly composed of pyrite and sphalerite, with minor amounts of native gold, galena and chalcopyrite. Gangue minerals consist predominantly of quartz, with subordinate potassium feldspar, sericite, calcite, and minor chlorite, epidote, and fluorite (Fig 5, 6). Native gold occurs mainly as irregular, discrete grains included in or adjacent to sulfides and quartz, ranging in grain size from 100 to 500 μm (Fig 5c, 5g and 5h). The ores are characterized by vein, disseminated, massive, breccia, comb and vug textures (Fig 5b-5f), and crystalline, metasomatic and solid solution exsolution structures (Fig 5g-5o). 3.3 Hydrothermal alteration and mineralization stages Hydrothermal alteration at the Shijia gold deposit occurs commonly as narrow, typically 20 to 50 cm wide haloes enveloping quartz vein and includes potassic alteration, silicification, sericitization, sulfidation and carbonatization (Fig. 6a, b). Potassic alteration, shown as the replacement of plagioclase by K-feldspar, is the earliest alteration and predates the mineralization. It occurs usually at the periphery of the alteration zone, with a distinct boundary with the wall rock (Fig. 6b). Silicification during the ore-stage occurs typically along with sericitization and sulfidation, both as quartz veins/veinlets and as pervasive silicas in the altered wall rocks (Fig. 6c, d). Pervasively distributed quartz, sericite and pyrite form a beresitization zone and commonly superimpose the potassic alteration zone (Fig. 6e). The latest, unmineralized quartz and calcite occur usually as quartz-calcite veins/veinlets that cut the earlier alteration zones (Fig. 7e-7g). Fluoritization, chloritization and epidotization are weak and only locally observed (Fig. 6f-6h). Based on the mineralogy, texture and crosscutting relationships (Fig.7), the mineralization process can be divided into three stages: (Ⅰ) quartz-sericite-pyrite stage, 7

(Ⅱ) quartz-sulfide-gold stage, and (Ⅲ) quartz-calcite-fluorite stage. Gold precipitated predominantly during stage II. The mineral assemblages of every stage are summarized in Fig. 8. (I) Quartz (Qz1)-sericite-pyrite stage Hydrothermal minerals of this stage include quartz, pyrite, and sericite. Quartz occurs as fine-grained, milky white veins or is pervasive in altered monzogranite. The quartz veins are locally fractured and cemented by later stage smoky gray or milky white quartz (Fig. 7a-7c). Generally, sericite and pyrite are sparsely disseminated in quartz veins and altered monzogranite. Pyrite of this stage is rare and commonly shows euhedral to subhedral crystal habits. (II) Quartz (Qz2)-sulfide-gold stage This is the main ore stage and often forms high-grade quartz vein ores in the Shijia gold deposit. Hydrothermal minerals mainly include quartz, pyrite and sphalerite, with a small amount of galena, chalcopyrite and native gold. Quartz of this stage is typically smoky gray to milky white, and occurs commonly as veins with a width varying from 10 to 50 cm. Smokey gray quartz (Qz2a) is fine-grained, and often contains fine-grained disseminated sulfides. It is commonly concentrated along the margin of quartz veins and is locally brecciated and cemented by milky white quartz (Fig. 7d). Milky white quartz (Qz2b) is coarse-grained, has a euhedral to subhedral crystal habit, and often shows comb textures (Fig. 7b). The quartz veins of stage Ⅱ usually cut the earlier stage quartz veins and altered monzogranite and are in turn cut by later stage quartz-calcite veins (Qz3) (Fig. 7e, 7f). Pyrite, sphalerite and galena have euhedral to anhedral granular textures, and are mainly distributed at the margin of quartz veins. Sphalerite is often intergrown with pyrite and replaced by galena (Fig. 5k), while chalcopyrite either replaces other sulfides or occurs as solid solutions in sphalerite (Fig. 5l-5o). (III) Quartz (Qz3)-calcite-fluorite stage Hydrothermal minerals of this stage mainly include quartz and calcite, locally with minor fluorite. Quartz is milky white to gray and occurs often as veins along with white to pink calcite (Fig. 7g). The quartz-calcite or calcite veins usually crosscut 8

the earlier quartz-sulfide veins and altered rocks. Calcite is pink and white, and fills the late-formed tensional fracture. Fluorite is locally observed, generally dark green, and often spatially associates with calcite (Fig. 6f, 7h). 3.4 Deformation after mineralization Affected by later tectonic-magmatic activities, the orebodies suffered several times of deformation after formation. Regional strike-slip movements caused the discontinuity and the lens-like shape of orebodies (Fig. 9a, b), and resulted in the formation of S-C fabrics, rotated porphyroclasts and asymmetrical folds (Fig. 9c-9e). Moreover, the orebodies were locally cut and dislocated by small-scale strike-slip faults with different strikes and different directions of movement (Fig. 9f-9h). In addition, the emplacement of dykes also caused the discontinuity and displacement of orebodies. 4 Relationship between orebodies and dykes The dykes exposed in the ore district include granite pegmatite, lamprophyre, diabase and granite porphyry, and they all intruded into the Guojialing monzogranite. Field investigation shows that there is a clear crosscutting relationship between orebodies and dykes. Granite pegmatites are usually cut and displaced by gold-bearing quartz veins and were altered near the orebody, indicating that granite pegmatites were predated the gold mineralization (Fig. 10a, b). Spatially, lamprophyre and diabase dykes are distributed commonly along one or both sides of auriferous quartz veins, and occasionally the dykes clearly crosscut the ore veins (Fig. 10c, d). In addition, an obvious chilled border was observed at the margin of the lamprophyre and diabase dykes (Fig.10e, f), indicating that the lamprophyre and diabase dykes were postdated the gold mineralization. Locally, the gold-bearing quartz veins are observed to be cut by granite porphyry (Fig. 10g), suggesting that the granite porphyry was also postdated the mineralization. Obvious crosscutting relationships were also observed among different dykes. Granite pegmatites are truncated and dislocated not only by gold-bearing quartz veins, but also by lamprophyre and diabase dykes (Fig. 10h, i). Lamprophyre is often crosscut by diabase (Fig. 10j), while diabase is usually cut by later granite porphyry 9

(Fig. 10k). Accordingly, the formation sequence of the ore veins and magmatic rocks at Shijia is as follows: monzogranite (host rock), granite pegmatite, auriferous quartz veins, lamprophyre, diabase, and granite porphyry.

5. Zircon U-Pb geochronology 5.1 Sampling and analytical methods Samples for LA-ICP-MS zircon U-Pb dating were collected from the underground mine and include granite pegmatite, lamprophyre, diabase and granite porphyry. The granite pegmatite sample (WJY-1Zr) was collected near the No. 28 exploration line at the -475 m level. Samples for lamprophyre (HBY-1Zr) and diabase samples (SCBY-1Zr) were collected from the No. 76 exploration line at the -395 m level. Granite porphyry (SYBY-1Zr) was gathered from the No. 16 exploration line at the -435 m level (Fig. 3). Separation of zircon grains was completed in Langfang Integrity Geological Service Company, Hebei Province, China. Cathodoluminescence (CL) imaging was carried out at Jingwei Analytical Technology Co., Ltd, Guiyang, Guizhou Province, China. Zircon U-Pb dating was conducted using a Thermo Fisher’s X-Series Ⅱ ICP-MS instrument connected with a Coherent GeoLasPro-193nm laser at the State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences, Beijing. Helium was used as the carrier gas and was mixed with argon prior to entering the ICP-MS torch. All data were acquired on zircon in single-spot ablation mode using a spot size of 32 μm with 6 Hz laser pulse repetition rate. Isotope measurements were using zircon 91500 as the external standard for U-Th-Pb isotopic ratios (Wiedenbeck et al., 1995, 2004), NIST610 as the external standard for determination of trace elements, and Plesovice as a monitoring standard for each analysis. Time-dependent drifts of U-Th-Pb isotopic ratios were corrected using linear interpolation over time for every five analyses according to the variations of the 91500 standard. For each analysis, 20 seconds of background were acquired followed by 50 seconds of signal. Quantification of trace-element concentrations and U-Pb zircon dates were carried out using the ICPMSDataCal program (Liu et al., 2008). 10

The age calculations and plotting of Concordia diagrams were made by using Isoplot (Ludwig, 2003). 5.2 Results The zircon U-Pb analytical results are summarized in Table 1. Zircon CL images are shown in Fig. 11, and the age data are plotted in Fig. 12. Zircon grains in the sample WJY-1Zr from granite pegmatite are colourless or light-brown, transparent to translucent, euhedral to subhedral prismatic with a length varying from 80 to 250 μm and length to width ratios ranging from 1:1 to 5:1. They show clear oscillatory zoning in CL images (Fig. 11a). Eleven zircon grains (excluding of the captured zircon grains and the data suffered lead loss) exhibit large ranges of Th (111-215 ppm) and U (241-393 ppm) contents, with Th/U ratios varying from 0.38 to 0.56. Their features are consistent with typical magmatic zircons. The 206Pb/238U

ages range from 127.1 to 132.5 Ma, with a weighted mean age of 129.7 ±

1.6 Ma (MSWD = 0.4) (Fig. 12a), representing the crystallization time of granite pegmatite. Zircons from the sample HBY-1Zr of lamprophyre dyke are colourless or light-brown, transparent to translucent, and euhedral to subhedral. They typically have a prismatic morphology with a length varying from 50 to 200 μm and length to width ratios ranging between 1:1 and 4:1, and show clear oscillatory zoning in CL images (Fig. 11b). The Th and U concentrations of fifteen zircon grains range from 104 to 291 ppm and from 213 to 556 ppm, respectively, with Th/U ratios of 0.28 to 0.58, representing a magmatic origin. The

206Pb/238U

ages range from 123.7 to 136.1 Ma,

with a weighted mean age of 129.3 ± 1.4 Ma (MSWD = 0.7) (Fig. 12b). Zircon grains in the sample SCBY-1Zr from the diabase dyke are colourless, transparent, and generally euhedral with a length ranging from 50 to 100 μm. They show a short-prismatic morphology with length to width ratios varying from 1:1 to 3:1, and clear oscillating zoning (Fig. 11c). The zircon grains have variable Th (81-322 ppm) and U (266-532 ppm) contents, with Th/U ratios ranging from 0.24 to 0.64, suggesting magmatic origin. Eighteen zircon grains yielded concordant ages that vary from 122.8 Ma to 133.2 Ma, with a weighted mean age of 128.3 ± 1.1 Ma 11

(MSWD = 1.1) (Fig. 12c). This age is interpreted to represent the timing of emplacement for the diabase dyke. The zircons from the sample SYBY-1Zr of granite porphyry are colourless, transparent, and euhedral with a long-prismatic morphology and clear oscillatory zoning (Fig. 11d). The length of these zircon grains ranges from 100 to 300 μm with length to width ratios varying from 1:1 to 5:1. The Th and U concentrations range from 172 to 1055 ppm and from 102 to 628 ppm, respectively, with Th/U ratios from 0.75 to 2.70, showing characteristics of magmatic zircons. Twenty-two zircon grains outlined concordant ages varying from 116.3 Ma to 124.7 Ma and a weighted mean age of 120.0 ± 1.1 Ma (MSWD = 1.0) (Fig. 12d).

6. Discussion 6.1 Timing of the gold mineralization and its significance Previous isotopic dating using different geochronological methods, including Ar-Ar isotopic dating on sericite and quartz, Rb-Sr isochron age of pyrite and SHRIMP U-Pb age of hydrothermal zircons, has shown that the gold deposits in the Jiaodong Peninsula formed in a relatively short period in the Early Cretaceous. In the Pengjiakuang gold deposit, gold-bearing quartz from brecciated and veinlet ores yielded

40Ar/39Ar

isochron ages of 117.03 ± 0.13 Ma and 117.33 ± 0.15 Ma,

respectively (Zhang et al., 2003a). In the Dayinggezhuang gold deposit, hydrothermal sericite outlined

40Ar/39Ar

plateau ages of 126.8 ± 0.59 Ma to 133.37 ± 0.56 Ma

(Yang et al., 2014b). The Rb-Sr isochron ages of pyrite in the Hexi, Heilan’gou, Daliuhang and Xincheng gold deposits are 122.3 ± 3.1 Ma, 117.8 ± 6.5 Ma (Hou et al., 2006) and 122.0 ± 7.4 Ma to 125.7 ± 5.6 Ma (Wang et al., 2015), respectively. In the Rushan gold deposit, hydrothermal zircons from auriferous quartz veins yielded a weighted average age of 117 ± 3 Ma (Hu et al., 2004). The mineralization age of other gold deposits in Jiaodong such as Fayunkuang, Cangshan, Jiehe, Hubazhuang, Wang’ershan and Daliuhang gold deposits is also limited to be the Early Cretaceous (Zhang et al., 2003b; Zhang et al., 2003c; Bi et al., 2017; Cai et al., 2011; Yang et al., 2017; Feng et al., 2019). In addition, the crosscutting relationship between orebodies 12

and related geological bodies (host rocks and dykes) can also help to determine the mineralization time. For example, Wang et al. (1999) limited the mineralization ages of gold deposits in Jiaodong to be between 126 Ma and 120 Ma, according to the relationship among gold-bearing quartz veins, ore-bearing granites and dyke swarms. Song et al. (2018b) reported SHRIMP zircon ages for pre-metallogenic and post-metallogenic mafic dykes, and concluded that the timing of mineralization for the Jiaojia gold deposit should be from 124 Ma to 112 Ma. Based on the crosscutting relationship between Au orebodies and intermediate-mafic dykes, Chai et al. (2019) believed that the age of Xiejiagou gold mineralization occurred at ~123.6 to 115.2 Ma. All these reported isotopic dates show that the formation time of most gold deposits in Jiaodong varies between 130 Ma and 110 Ma. There is yet no report on the mineralization time for the Shijia gold deposit. As described above, the obvious crosscutting relationship between the ore veins and different types of dykes at Shijia has made it possible to limit the timing of mineralization. The LA-ICP-MS zircon U-Pb isotopic dating in this study shows that the emplacement ages of granite pegmatite, lamprophyre, diabase and granite porphyry in the deposit are 129.7 ± 1.6 Ma, 129.3 ± 1.4 Ma, 128.3 ± 1.3 Ma and 120.0 ± 1.1 Ma, respectively. Field observation indicates that the gold mineralization was postdated the emplacement of granite pegmatite but predated the emplacement of lamprophyre, diabase and granite porphyry dykes, the mineralization age is thus confined between 129.7 Ma and 129.3 Ma, consistent to most of the gold deposits in the Jiaodong Peninsula. The consistency of the mineralization age at Shijia with other gold deposits in Jiaodong implies that they were formed within a relatively short time period and might have formed under the same tectonic setting with a similar genetic mechanism. Chen et al. (2004, 2005) considered that the collision between the South and North China continents was probably the key factor responsible for the gold mineralization in the Jiaodong gold province. Goldfarb and Santosh (2014) proposed that a downing subduction slab and overlying sediments were the most likely source of ore-forming fluid and metal reservoirs for the gold deposits in Jiaodong. However, many other 13

researchers emphasized the importance of lithospheric extension and thinning of the NCC in the Early Cretaceous, magmatic fluid and mantle-derived materials for the formation of gold deposits in Jiaodong and its adjacent areas (Zhai et al., 2001, 2004; Liu et al., 2001; Yang et al., 2003; Mao et al., 2005, 2008; Jiang et al., 2009; Guo et al., 2013; Li et al., 2015; Wen et al., 2015; Yang et al., 2015; Zhu et al., 2015; Fan et al., 2016; Li et al., 2017; Wen et al., 2017; Cai et al., 2018; Ma et al., 2018; Tan et al., 2018; Yuan et al., 2019). In the Paleozoic, the NCC has a thick lithosphere with a thickness of 200 km (Lu et al., 1991; Griffin et al., 1998). During Mesozoic times, drastic changes in tectonic regime occurred in eastern Asia, where the Cretaceous witnesses a large-scale extensional event (Charles et al., 2011). The paleo-Pacific plate subducted beneath the NCC at ~160 Ma and then retreated at ~140 Ma (Zheng and Dai, 2018). Bottom of the craton lithosphere was heated by the asthenospheric mantle filled laterally, which resulted in the thinning of the weakened craton lithospheric mantle (Dai et al., 2016) and reached its peak decratonization during 130~120 Ma (Jiang et al., 2005; Wu et al., 2005; Zhu et al., 2011, 2019; Zheng et al., 2018). Contemporaneously, the shallow crust was accompanied by the formation of metamorphic core complexes, the appearance of fault basins, extensional fault activities, large-scale volcanic eruption and magma emplacement (Zhu et al., 2012; Zhu et al., 2016). Low-Ti and high-Ti lamprophyres that derived from partial melting of an ancient enriched lithospheric mantle and a convective asthenospheric mantle, respectively, simultaneously intruded the eastern NCC about 121 Ma ago. The co-occurrence of the two types of lamprophyres record a rapid transition from lithospheric to asthenospheric mantle sources, indicating the lithosphere beneath the eastern NCC was rapidly detached at a depth of 75~85 km just prior to ca. 121 Ma at Jiaodong Peninsula (Ma et al., 2014). Moreover, the geochemical characteristics of mafic rocks in North China changed significantly at ~121 Ma. At that time, the mafic rocks exhibit OIB-like trace element distribution patterns, relatively depleted radiogenic Sr-Nd isotope compositions and high initial 206Pb/204Pb ratios, while before ~121 Ma, the mafic rock generally exhibit arc-like trace element distribution patterns, enriched radiogenic Sr-Nd isotope compositions and relatively low initial 14

206Pb/204Pb

ratios (Dai et al., 2016; Zheng et al., 2018). The change of geochemical properties of mafic rocks may indicate that the ancient subcontinental lithospheric mantle (SCLM) had been replaced by the juvenile SCLM, which also marked the termination of peak decratonization in North China (Dai et al., 2016). The destruction of the lithospheric mantle and upwelling of the asthenosphere resulted in extensive magmatism and intense crust-mantle interaction. This process might provide sufficient heat energy, ore-forming fluids and materials for the formation of gold deposits.The mineralization time of the Shijia deposit as well as many other gold deposits in Jiaodong coincides with the emplacement of mafic-felsic dykes, the exhumation of metamorphic core complexes, the formation time of intracontinental rift basins and the peak decratonization of the NCC, indicating that these gold deposits formed under the large-scale extension and thinning of the NCC associated with the Pacific plate subduction. 6.2 Association between lamprophyre and gold deposits In many cases, lamprophyres derived from the ancient enriched lithospheric mantle, especially calc-alkaline lamprophyres, are closely associated with lode-gold deposits. Compared with other igneous rocks, lamprophyres commonly have higher average gold abundances, and lamprophyre magmas are generally rich in volatiles (e.g., CO2, H2O and F) and large ion lithophile elements (LILE, e.g., K, Rb and Ba), implying that lamprophyric melts are similar to mineralizing fluids in gold alteration systems. Therefore, lamprophyres are regarded as transporting agents of Au from Au-rich sources in the deep mantle (Rock and Groves, 1988a, 1998b; Rock, 1991). However, there are also some doubts about this genetic model, such as whether the anomalous gold content in lamprophyres is primary or secondary, and the significance of the association between vein deposits and lamprophyres (e.g., Wyman and Kerrich, 1988). Subsequent studies show that the anomalous gold content in lamprophyres is related to later stage hydrothermal alteration, whereas the original gold content in lamprophyres was overestimated (Ashley et al., 1994; Taylor et al., 1994; Li and Sun, 1995; Müller and Groves, 2016; Li et al., 2019). Furthermore, high temperature and ultrahigh pressure experiments show that lamprophyre magma has poor gold carrying 15

capacity (Huang et al., 1999a, 1999b; Li et al., 2009). Hence, lamprophyre is less possible to provide Au for the mineralization process. Although the ores share the similar isotopic characteristics with the various types of wall rocks, the late-Archean and Paleoproterozoic metamorphic rocks and the late-Jurassic Linglong and Luanjiahe granitoids are ruled out because they were metamorphosed or emplaced earlier than the mineralization (Goldfarb and Santosh, 2014; Deng et al., 2015; Groves and Santosh, 2016; Yang et al., 2016). Meanwhile, the Guojialing granitoids which have temporal overlap with the gold mineralization, show no obvious spatial association between these mantle-crustal melts and the gold ores and their hosting structures, or evidence of thermally-induced metal zonation (Goldfarb and Santosh, 2014; Goldfarb and Groves, 2015). The mafic dykes, including lamprophyre, are widely distributed in the Jiaodong gold province and its adjacent areas, and have significant temporal and spatial relationships with gold orebodies. Thus, some researchers believed that these dykes may have played an important role in the process of gold mineralization. For example, the magma of mafic dykes may provide metals and fluids needed (Li et al., 2012; Ma et al., 2017), keep gold in ionic stage in the form of Au+1 or Au+3 (Li et al., 2016), or act as an impervious layer to prevent the loss of ore-forming fluids (Yang et al., 2014c; Li et al., 2015a). Previous isotope studies indicate that mantle-derived fluids and materials are involved in the mineralization (Zhang et al., 2002; Liu et al., 2003; Mao et al., 2005, 2008; Tan et al., 2018), and that the S and Pb isotopic compositions of ores are consistent with those of the dykes (Li et al., 2015b), which may indicate that lamprophyres and other mafic dykes provided ore-forming materials during the mineralization process. However, since gold mineralization and mafic dykes share the same source (Shen et al., 2005; Mao et al., 2008; Tan et al., 2012; Yuan et al., 2019), the S and Pb isotopic compositions of ores are not necessarily inherited from mafic magmas. Moreover, lamprophyre cannot provide Au for the mineralization process. Therefore, lamprophyre and other mafic dykes may not have a direct genetic relationship with gold deposits. Similar to other gold deposits in the Jiaodong Peninsula, although lamprophyre dykes exposed at Shijia are spatially associated with 16

gold orebodies, their emplacement time was slightly later than the mineralization, indicating that lamprophyres could not provide the ore-forming materials for mineralization or play the role as impervious layers. The same tectonic background resulted in the similarity in their formation time, while the same migration pathway led to their superposition in space. Although lamprophyre dykes do not play a role in providing ore-forming materials in the process of gold mineralization, the space and time connection between orebodies and lamprophyres could still be used as an effective prospecting indicator.

7. Conclusions (1) The Shijia gold deposit is a quartz vein-type gold deposit hosted in the Early Cretaceous Guojialing amphibole-bearing monzogranite. Orebodies are strictly controlled by NNE- to NE-striking high-angle faults and occur as quartz veins accompanied by silicification, sericitization, sulfidation and carbonatization. The mineralization

process

quartz-sericite-pyrite

can stage,

be the

divided

into

three

quartz-sulfide-gold

stages, stage

namely

the

and

the

quartz-calcite-fluorite stage. (2) Granite pegmatite, lamprophyre, diabase and granite porphyry occur as dykes and are widely distributed in the Shijia gold deposit. The crosscutting relationship between orebodies and mafic-felsic dykes shows that the sequence of their formation is granite pegmatite, orebodies, lamprophyre, diabase and granite porphyry. The emplacement ages obtained the LA-ICP-MS zircon U-Pb isotopic dating on granite pegmatite, lamprophyre, diabase, and granite porphyry are 129.7 ± 1.6 Ma, 129.3 ± 1.4 Ma, 128.3 ± 1.3 Ma and 120.0 ± 1.1 Ma, respectively, indicating that the mineralization age of the Shijia gold deposit is between 129.7 Ma and 129.3 Ma, at ca. 129 Ma. (3) The Shijia gold deposit was formed under the background of extension and thinning of the NCC. The space and time connection between lamprophyres and orebodies may not imply a direct genetic relationship, but be related to their common tectonic setting and migration channel. 17

Acknowledgements The authors would like to thank the staff of the Penglai Wantai Mining Co., Ltd for their support and guidance in the field. The manuscript has been significantly improved from constructive comments by Dr. Yanlu Xing from Monash University. This research was funded by the National Natural Science Foundation of China (Grant No. 41572062), the National Key R&D Program of China (Grant No. 2018YFC0604003) and the Fundamental Research Funds for the Central Universities (Grant No. 2652017226).

References Ashley, P.M., Cook, N.D. J., Hill, R.L., Kent, A.J.R., 1994. Shoshonitic lamprophyres dykes and their relation to mesothermal Au-Sb veins at Hillgrove, New South Wales, Australia. Lithos, 21, 249-272. Bi, S.J., Zhao, X.F., 2017. 40Ar/39Ar dating of the Jiehe gold deposit in the Jiaodong Peninsula, eastern North China Craton: Implications for regional gold metallogeny. Ore Geology Reviews, 86, 9-651. Cai, Y.C., Fan, H.R., Hu, F.F., Yang, K.F., Lan, T.G., Yu, H., Liu, Y.M., 2011. Ore-forming fluids, stable isotope and mineralizing age of the Hubazhuang gold deposit, Jiaodong Peninsula of eastern China. Acta Petrologica Sinica, 27, 1342-1351 (in Chinese with English abstract). Cai, Y.C., Fan, H.R., Santosh, M., Hu, F.F., Yang, K.F., Li, X.H., 2018. Decratonic gold mineralization: Evidence from the Shangzhuang gold deposit, eastern North China Craton. Gondwana Research, 2018, 54, 1-22. Chai, P., Hou, Z.Q., Zhang, H.R., Dong, L.L., 2019. Geology, fluid inclusion, and H-O-S-Pb isotope constraints on the mineralization of the Xiejiagou gold deposit in the Jiaodong Peninsula. Geofluids, 2019, 1-23. Charles, N., Gumiaux, C., Augier, R., Chen, Y., Zhu, R.X., Lin, W., 2011. Metamorphic core complexes vs. synkinematic plutons in continental extension setting: insights from key structures (Shandong Province, eastern China). Journal of Asian Earth Science, 40, 261-278. 18

Chen, Y.J., Pirajno, F., Lai, Y., Li, C., 2004. Metallogenic time and tectonic setting of the Jiaodong gold province, eastern China. Acta Petrologica Sinica, 20, 907-920 (in Chinese with English abstract). Chen, Y.J., Pirajno, F., Qi, J.P., 2005. Origin of gold metallogeny and sources of ore-forming fluids, Jiaodong province, eastern China. International Geology Review, 47, 530-549. Chu, H., Lu, S.N., Wang, H.C., Xiang, Z.Q., Liu, H., 2011. U-Pb age spectrum of detrital zircons from the Fuzikuang Formation, Penglai Group in Changdao, Shandong Province. Acta Petrologica Sinica, 27, 1017-1028 (in Chinese with English abstract). Dai, L.Q., Zheng, Y.F., Zhao, Z.F., 2016. Termination time of peak decratonization in North China: Geochemical evidence from mafic igneous rocks. Lithos, 240-243, 327-336. Deng, J., Liu, X.F., Wang, Q.F., Pan, R.G., 2015. Origin of the Jiaodong-type Xinli gold deposit, Jiaodong Peninsula, China: Constraints from fluid inclusion and C-D-O-S-Sr isotope compositions. Ore Geology Reviews, 65, 674-686. Fan, H.R., Zhai, M.G., Xie, Y.H., Yang, J.H., 2003. Ore-forming fluids associated with granite-hosted gold mineralization at the Sanshandao deposit, Jiaodong gold province, China. Mineralium Deposita, 38, 739-750. Fan, H.R., Hu, F.F., Yang, J.H., Shen, K., Zhai, M.G., 2005. Fluid evolution and large-scale gold metallogeny during Mesozoic tectonic transition in the eastern Shandong Province. Acta Petrologica Sinica, 21, 1317-1328 (in Chinese with English abstract). Fan, H.R., Feng, K., Li, X.H., Hu, F.F., Yang, K.F., 2016. Mesozoic gold mineralization in the Jiaodong and Korean peninsulas. Acta Petrologica Sinica, 32, 3225-3238 (in Chinese with English abstract). Feng, K., Fan, H.R., Groves, D.I., Yang, K.F., Hu, F.F., Liu, X., Cai, Y.C., 2019. Geochronological and sulfur isotopic evidence for the genesis of the post-magmatic, deeply sourced, and anomalously gold-rich Daliuhang orogenic deposit,

Jiaodong,

China. 19

Mineralium

Deposita,

https://doi.org/10.1007/s00126-019-00882-8. Goldfarb, R.J., Santosh, M., 2014. The dilemma of the Jiaodong gold deposits: Are they unique? Geoscience Frontiers, 5, 139-153. Goldfarb, R.J., Groves, D.I., 2015. Orogenic gold: Common vs evolving fluid and metal sources through time. Lithos, 233, 2-26. Griffin, W.L., Zhang, A.D., O’Reilly, S.Y., Ryan, C.G., 1998. Phanerozoic evolution of the lithosphere beneath the Sino-Korean Craton. Mantle Dynamics and Plate Interactions in East Asia, 27, 107-126. Groves, D.I, Santosh, M., 2016. The giant Jiaodong gold province: The key to a unified model for orogenic gold deposits? Geoscience Frontiers, 7, 409-417. Guo, F., Fan, W.M., Wang, Y.J., Zhang, M., 2004. Origin of early Cretaceous calc-alkaline lamprophyres from the Sulu orogen in eastern China: Implications for enrichment processes beneath continental collisional belt. Lithos, 78, 291-305. Guo, P., Santosh, M., Li, S.R., 2013. Geodynamics of gold metallogeny in the Shandong Province, NE China: An integrated geological, geophysical and geochemical perspective. Gondwana Research, 24, 1172-1202. Guo, W.K., Duan, C.J., 1951. Linglong gold deposit, Zhaoyuan City, Shandong Province. Geological Review, 16, 112-113 (in Chinese with English abstract). Hou, M.L., Jiang, S.Y., Jiang, Y.H., Ling, H.F., 2006. S-Pb isotope geochemistry and Rb-Sr geochronology of the Penglai gold field in the eastern Shangdong Province. Acta Petrologica Sinica, 22, 2525-2533 (in Chinese with English abstract). Hu, F.F, Fan, H.R., Yang, J.H., Wang,, Y.S., Liu, D.Y., Zhai, M.G., Jin, C.W., 2004. Mineralization age of the Rushan lode gold deposit in the Jiaodong Peninsula: SHRIMP U-Pb dating on hydrothermal zircon. Chinese Science Bulletin, 49: 1629-1636. Hu, F.F., Fan, H.R., Jiang, X.H., Li, X.C., Yang, K.F., Mernagh, T., 2013. Fluid inclusions at different depths in the Sanshandao gold deposit, Jiaodong Peninsula, China. Geofluids, 13, 528-541. 20

Huang, Z.L., Zhu, C.M., Xiao, H.Y., Liu, C.Q., 1999a. Do lamprophyric magma carry gold?——Evidence from high temperature and ultrahigh pressure experiments. Chinese Science Bulletin, 44, 2073-2076. Huang, Z.L., Zhu, C.M., Xiao, H.Y., Liu, C.Q., 1999b. An experiment study of liquid immiscibility of lamprophyre-sulfide melt at high temperature and high pressure. Geological Reviews, 45, 113-119 (in Chinese with English abstract). Jahn, B.M., Liu, D.Y., Wan, Y.S., Song, B., Wu, J.S., 2008. Archean crustal evolution of the Jiaodong Peninsula, China, as revealed by zircon SHRIMP geochronology, elemental and Nd-isotope geochemistry. American Journal of Science. 308, 232-269. Jiang, S.Y., Dai, B.Z., Jiang, Y.H., Zhao, H.X., Hou, M.L., 2009. Jiaodong and Xiaoqinling: two orogenic gold provinces formed in different tectonic settings. Acta Petrologica Sinica, 25, 2727-2738 (in Chinese with English abstract). Jiang, Y.H., Jiang, S.Y., Zhao, K.D., Ni, P., Ling, H.F., Liu, D.Y., 2005. SHRIMP U-Pb zircon dating for lamprophyre from Liaodong Peninsula: Constraints on the initial time of Mesozoic lithosphere thinning beneath eastern China. Chinese Science Bulletin, 50, 2612-2620. Li, B., Huang, Z.L., Zhu, C.M., 2009. Experimental study on liquid immiscibility of lamprophyre-sulfide melt at high temperature and high pressure and its geological significance. Chinese Journal of Geochemistry, 28, 198-203. Li, H.J., Wang, Q.F., Groves, D.I., Deng, J., Dong, C.Y., Wang, X., 2019. Alteration of Eocene lamprophyres in the Zhenyuan orogenic gold deposit, Yunnan Province, China: Composition and evolution of ore fluids. Ore Geology Reviews, 107, 1068-1083. Li, J.W., Bi, S.J., Vasconcelos, P.M., 2010. Mineralization and genesis of the Fanjiabu gold deposit in the Sulu ultrahigh pressure metamorphic terrain, with a comparison to the gold mineralization in the Jiaobei Terrain. Geological Journal of China Universities, 16, 125-142 (in Chinese with English abstract). Li, J.W., Bi, S.J., Selby, D., Chen, L., Vasconcelos, P., Thiede, D., Zhou, M.F., Zhao, X.F., Li, Z.K., Qiu, H.N., 2012. Giant Mesozoic gold provinces related to the 21

destruction of the North China Craton. Earth and Planetary Science Letters, 349-350, 26-37. Li, Q., Santosh, M., Li, S.R., Zhang, J.Q., 2015a. Petrology, geochemistry and zircon U-Pb and Lu-Hf isotopes of the Cretaceous dykes in the central North China Craton: Implications for magma genesis and gold metallogeny. Ore Geology Reviews, 67, 57-77. Li, L., Santosh, M., Li, S.R., 2015b. The ‘Jiaodong type’ gold deposits: Characteristics, origin and prospecting. Ore Geology Reviews, 65, 589-611. Li, L., Li, S.R., Santosh, M., Li, Q., Gu, Y., Lü, W.J., Zhang, H. F., Shen, J. F., Zhao, G. C., 2016. Dyke swarms and their role in the genesis of world-class gold deposits: Insights from the Jiaodong Peninsula, China. Journal of Asian Earth Sciences, 130, 2-22. Li, S.R., Santosh, M., 2017. Geodynamics of heterogeneous gold mineralization in the North China Craton and its relationship to lithospheric destruction. Gondwana Research, 50, 267-292. Li, X.H., Sun, X.S., 1995. Lamprophyre and gold mineralization—An assessment of observations and theories. Geology Review, 41, 252-260 (in Chinese with English abstract). Li, X.Y., Li, S.Z., Suo, Y.H., Somerville, I.D., Huang, F., Liu, X., Wang, P.C., Han, Z.X., Jin, L.J., 2018. Early Cretaceous diabases, lamprophyres and andesites-dacites in western Shandong, North China Craton: Implications for local delamination and Paleo-Pacific slab rollback. Journal of Asian Earth Sciences, 160, 426-444. Li, Y.J., Li, S.R., Santosh, M., Liu, S.A., Zhang, L., Li, W.T., Song, Y.X., Wang, B.X., 2015. Zircon geochronology, geochemistry and stable isotopes of the Wang’ershan gold deposit, Jiaodong Peninsula, China. Journal of Asian Earth Sciences, 113, 695-710. Li, Z.L., Yang, M.Z., 1993. Geological and geochemical characteristics of Jiaodong gold deposit. Tianjin: Tianjin Science and Technology Press. Liu, J.M., Ye, J., Xu, J.H., Jiang, N., Ying, H.L., 2001. Preliminary discussion on 22

geodynamic background of Mesozoic gold metallogeny in eastern north China—with examples from eastern Shandong Province. Progress in Geophysics, 16, 39-46 (in Chinese with English abstract). Liu, J.M., Ye, J., Xu, J.H., Sun, J.G., Shen, K., 2003. C-O and Sr-Nd isotopic geochemistry of carbonate minerals from gold deposits in east Shandong, China. Acta Petrologica Sinica, 19, 775-784 (in Chinese with English abstract). Liu, S., Hu, R.Z., Gao, S., Feng, C.X., Yu, B.B., Feng, G.Y., Qi, Y.Q., Wang, T., Coulson, I.M., 2009. Petrogenesis of Late Mesozoic mafic dykes in the Jiaodong Peninsula, eastern North China Craton and implications for the foundering of lower crust. Lithos, 113, 621-639. Liu, Y.S., Hu, Z.C., Gao, S., Chen, H.H., 2008. In situ analysis of major and trace elements of anhydrous minerals by LA-ICP-MS without applying an internal standard. Chemical Geology, 257, 34-43. Lu, F.X., Han, Z.G., Zheng, J.P., Ren, Y.X., 1991. Characteristics of Paleozoic mantle-lithosphere in Fuxian, Liaoning Province. Geological Science and Technology Information, 10, 2-20 (in Chinese with English abstract). Ludwing, K.R., 2001. Users manual for Isoplot /Ex rev. 2.49. Berkeley Geochronology Centre Special Publication, No.1a, 56. Ma, L., Jiang, S.Y., Hofmann, A.W., Dai, B.Z., Hou, M.L., Zhao, K.D., Chen, L.H., Li, J.W., Jiang, Y.H., 2014. Lithospheric and asthenospheric sources of lamprophyres in the Jiaodong Peninsula: A consequence of rapid lithospheric thinning beneath the North China Craton? Geochimica et Cosmochimica Acta, 124, 250-271. Ma, L., Jiang, S.Y., Hofmann, A.W., Xu, Y.G., Dai, B.Z., Hou, M.L., 2016. Rapid lithospheric thinning of the North China Craton: New evidence from cretaceous mafic dikes in the Jiaodong Peninsula. Chemical Geology, 432, 1-15. Ma, W.D., Fan, H.R., Liu, X., Pirajno, F., Hu, F.F., Yang, K.F., Yang, Y.H., Xu, W.G., Jiang, P., 2017. Geochronological framework of the Xiadian gold deposit in the Jiaodong. Ore Geology Reviews, 86, 196-211. Ma, W.D., Fan, H.R., Liu, X., Yang, K.F., Hu, F.F., Zhao, K.D., Cai, Y.C., Hu, H.L., 23

2018. Hydrothermal fluid evolution of the Jintingling gold deposit in the Jiaodong Peninsula, China: Constraints from U-Pb age, CL imaging, fluid inclusion and stable isotope. Journal of Asian Earth Sciences, 160, 287-303. Mao, J.W., Li, H.M., Wang, Y.T., Zhang, C.Q., Wang, R.T., 2005. The relationship between mantle-derived fluid and gold ore-formation in the eastern Shandong Peninsula: Evidence from D-O-C-S isotopes. Acta Geologica Sinica, 79, 839-857 (in Chinese with English abstract). Mao, J.W., Wang, Y.T., Li, H.M., Pirajno, F., Zhang, C.Q., Wang, R.T., 2008. The relationship of mantle-derived fluids to gold metallogenesis in the Jiaodong Peninsula: Evidence from D-O-C-S isotope systematics. Ore Geology Reviews, 33, 361-381. Müller, D., Groves, D.I., 2016. Indirect associations between lamprophyres and gold-copper deposits. In: Potassic Igneous Rocks and Associated Gold-Copper Mineralization. Springer, Switzerland, 203-226. Rock, N.M.S., Groves, D.I., 1988a. Do lamprophyres carry gold as well as diamonds? Nature, 332, 253-255. Rock, N.M.S., Groves, D.I., 1988b. Can lamprophyres resolve the controversy over mesothermal gold deposits? Geology, 16, 538-541. Rock, N.M.S., 1991. Lamprophyres. Glasgow: Blackie, 151-153. Shen, Y.K., Deng, J., Xu, Y.B., 2005. Geological significance of lamprophyre during gold mineralization in the Linglong ore field. Geology and Prospecting, 41, 45-49 (in Chinese with English abstract). Song, M.C., Li, S.Z., Yi, P.H., Cui, S.X., Xu, J.X., Lü, G.X., Song, Y.X., Jiang, H.L., Zhang, P.J., Huang, T.L., Liu, C.C., Liu, D.H., 2014. Classification and metallogenic theory of the Jiaojia-Style gold deposit in Jiaodong Peninsula, China. Journal of Jilin University (Earth Science Edition), 4, 87-104 (in Chinese with English abstract). Song, M.C., Li, S.Z., Santosh, M., Zhao, S.J., Yu, S., Yi, P.H., Cui, S.X., Lü, G.X., Xu, J.X., Song, Y.X., Zhou, M.L., 2015. Types, characteristics and metallogenesis of gold deposits in the Jiaodong Peninsula, Eastern North China 24

Craton. Ore Geology Reviews, 65, 612-625. Song, M.C., Song, Y.X., Ding, Z.J., Li, S.Y., 2018a. Jiaodong gold deposits: Essential characteristics and major controversy. Gold Science and Technology, 26, 406-422 (in Chinese with English abstract). Song, Y.X., Song, M.C., Sun, W.Q., Ma, X.D., Li, D.P., 2018b. Metallogenic epoch and regional crust evolution in the Jiaodong gold deposit, Shandong Province: Evidence from SHRIMP zircon U-Pb ages of mafic dykes. Geological Bulletin of China, 37, 908-919 (in Chinese with English abstract). Tan, J., Wei, J.H., Audétat, A., Pettke, T., 2012. Source of metals in the Guocheng gold deposit, Jiaodong Peninsula, North China Craton: Link to early Cretaceous mafic magmatism originating from Paleoproterozoic metasomatized lithospheric mantle. Ore Geology Reviews, 48, 70-87. Tan, J., Wei, J.H., He, H.Y., Su, F., Li, Y.J., Fu, L.B., Zhao, S.Q., Xiao, G.L., Zhang, F., Xu, J.F., Liu, Y., Stuart, F.M., Zhu, R.X., 2018. Noble gases in pyrites from the Guocheng-Liaoshang gold belt in the Jiaodong province: Evidence for a mantle source of gold. Chemical Geology, 480, 105-115. Taylor, W.R., Rock, N.M.S., Groves, D.I., 1994. Archean shoshonitic lamprophyres form the Yilgarn Block, Western Australia: Au abundance and association with gold mineralization. Applied Geochemistry, 9, 197-222. Wang, C.M., Deng, J., Santosh, M., Carranza, E.J.M., Gong, Q.J., Guo, C.Y., Xia, R., Lai, X.R. 2015. Timing, tectonic implications and genesis of gold mineralization in the Xincheng gold deposit, China: C-H-O isotopes, pyrite Rb-Sr and zircon fission track thermochronometry. Ore Geology Reviews, 65, 659-673. Wang, L.G., Qiu, Y.M., McNaughton, N.J., Groves, D.I., Luo, Z.K., Huang, J.Z., Miao, L.C., Liu, Y.K., 1998. Constraints on crustal evolution and gold metallogeny in the northwestern Jiaodong Peninsula, China, from SHRIMP U-Pb zircon studies of granitoids. Ore Geology Reviews, 13, 275-291. Wen, B.J., Fan, H.R., Santosh, M., Hu, F.F., Pirajno, F., Yang, K.F., 2015. Genesis of two different types of gold mineralization in the Linglong gold field, China: Constrains from geology, fluid inclusions and stable isotope. Ore Geology 25

Reviews, 65, 643-658. Wen, B.J., Fan, H.R., Hu, F.F., Liu, X., Yang, K.F., Sun, Z.F., Sun, Z.F., 2016. Fluid evolution and ore genesis of the giant Sanshandao gold deposit, Jiaodong gold province, China: Constraints from geology, fluid inclusions and H-O-S-He-Ar isotopic compositions. Journal of Geochemical Exploration, 171, 96-112. Wiedenbeck, M., Allé, P., Corfu, F., Griffin, W.L., Meier, M., Oberli, F., Albrecht von Quadt., Roddick, J.C., Spiegel, W., 1995. Three natural zircon standards for U-Th-Pb, Lu-Hf, trace element and REE analyses. Geostandards Newsletter, 19, 1-23. Wiedenbeck, M., Hanchar, J.M., Peck, W.H., Sylvester, P., Valley, J., Whitehouse, M., Kronz, A., Morishita, Y., Nasdala, L., Fiebig, J., Franchi, I., Girard, J.P., Greenwood, R.C., Hinton, Richard., Kita, N., Mason, P.R.D., Norman, M., Ogasawara, M., Piccoli, R., Rhede, D., Satoh, H., Schulz-Dobrick, B., Skar, O., Spicuzza, M.J., Terada, K., Tindle, A., Togashi, S., Vennemann, T., Xie, Q., Zheng, Y.F., 2004. Further characterization of the 91500 zircon crystal. Geostandards and Geoanalytical Research, 28, 9-39. Wu, F.Y., Lin, J.Q., Wilde, S.A., Zhang, X.O., Yang, J.H., 2005. Nature and significance of the Early Cretaceous giant igneous event in eastern China. Earth and Planetary Science Letters, 233, 103-119. Wyman, M., Kerrich, R., 1988. Lamprophyres a source of gold. Nature, 332, 209-210. Xie, S.W., Wang, S.J., Xie, H.Q., Liu, S.J., Dong, C.Y., Ma, M.Z., Liu, D.Y., Wan, Y.S., 2014. SHRIMP U-Pb dating of detrital zircons from the Fenzishan Group in eastern Shandong, North China Craton. Acta Geologica Sinica, 30, 2989-2998 (in Chinese with English abstract). Xue, J.L., Li, S.R., Pang, Z.S., Tao, W., Sun, W.T., Chen, H., Zhang, Y.Q., 2018. Ore-forming fluids, sources of materials in the Denggezhuang gold deposit, Jiaodong Peninsula and implications for ore genesis. Acta Geologica Sinica, 34, 1453-1468 (in Chinese with English abstract). Yang, J.H., Wu, F.Y., Wilde, S.A., 2003. A review of the geodynamic setting of large-scale Late Mesozoic gold mineralization in the North China Craton: an 26

association with lithospheric thinning. Ore Geology Reviews, 23, 125-152. Yang, K.F., Fan, H.R., Santosh, M., Hu, F.F., Wilde, S.A., Lan, T.G., Lu, L.N., Liu, Y.S., 2012. Reactivation of the Archean lower crust: implications for zircon geochronology, elemental and Sr-Nd-Hf isotopic geochemistry of late Mesozoic granitoids from northwestern Jiaodong Terrane, the North China Craton. Lithos, 146, 112-127. Yang, L.Q., Deng, J., Ge, L.S., Wang, Q.F., Zhang, J., Gao, B.F., Jiang, S.Q., Xu, H., 2006. Metallogenic epoch and genesis of the gold deposits in Jiaodong Peninsula, Eastern China: a regional review. Progress in Natural Science, 16, 797-802 (in Chinese with English abstract). Yang, L.Q., Deng, J., Wang, Z.L., Zhang, L., Guo, L.N., Song, M.C., Zheng, X.L., 2014a. Mesozoic gold metallogenic system of the Jiaodong gold province, eastern China. Acta Petrologica Sinica, 30, 2447-2467 (in Chinese with English abstract). Yang, L.Q., Deng, J., Goldfarb, R.J., Zhang, J., Gao, B.F., Wang, Z.L., 2014b. 40Ar/39Ar

geochronological constraints on the formation of the Dayingezhuang

gold deposit: New implications for timing and duration of hydrothermal activity in the Jiaodong gold province, China. Gondwana Research, 25, 1469-1483. Yang, L.Q., Deng, J., Guo, C.Y., Zhang, J., Jiang, S.Y., Gao, B.F., Gong, Q.J., Wang, Q.F., 2015. Ore-forming fluid characteristics of the Dayingezhuang gold deposit, Jiaodong gold province, China. Resource Geology, 59, 181-193. Yang, L.Q., Deng, J., Guo, R.P., Guo, L.N., Wang, Z.L., Chen, B.H., Wang, X.D., 2016. World-class Xincheng gold deposit: An example from the giant Jiaodong gold province. Geoscience Frontiers, 7, 419-430. Yang, L.Q., Guo, L.N., Wang, Z.L, Zhao, R.X., Song, M.C., Zheng, X.L., 2017. Timing and mechanism of gold mineralization at the Wang'ershan gold deposit, Jiaodong Peninsula, eastern China. Ore Geology Reviews, 88, 491-510. Yang, Q.Y., Santosh, M., Shen, J.F., Li, S.R., 2014c. Juvenile vs. recycled crust in NE China: Zircon U-Pb geochronology, Hf isotope and an integrated model for Mesozoic gold mineralization in the Jiaodong Peninsula. Gondwana Research, 27

25, 1445-1468. Yao, F.L., Liu, L.D., Kong, Q.C., Gong, R.T., 1990. Lode gold deposits in the northwest of Jiaodong. Changchun: Jilin Science and Technology Press. Yu, H.M., 1987. Geochronological study of rocks in the northwest of Jiaodong. Shandong Geology, 3, 75-88 (in Chinese with English abstract). Yuan, Z.Z., Li, Z.K., Zhao, X.F., Sun, H.S., Qiu, H.N., 2019. New constraints on the genesis of the giant Dayingezhuang gold (silver) deposit in the Jiaodong district, North

China

Craton.

Ore

Geology,

Reviews,

112,

103038,

10.1016/j.oregeorev.2019.103038. Zhai, M.G., Yang, J.H., Liu, W.J., 2001. Large clusters of gold deposits and large-scale metallogenesis in the Jiaodong Peninsula, Eastern China. Science in China, 44, 758-768. Zhai, M.G., Fan, H.R., Yang, J.H., Miao, L.C., 2004. Large-scale cluster of gold deposits in east Shandong: Anorogenic metallogenesis. Earth Science Frontiers, 11, 85-98 (in Chinese with English abstract). Zhang, L.C., Shen, Y.C., Li, H.M., Li, G.M., Liu, T.B., 2002. Helium and argon isotopic compositions of fluid inclusions and tracing to the source of ore-forming fluids for Jiaodong gold deposits. Acta Petrologica Sinica, 18, 559-565 (in Chinese with English abstract). Zhang, L.C., Liu, T.B., Shen, Y.C., Zeng, Q.D., Li, G.M., 2003a. Structure, isotopes, and

40Ar/39Ar

dating of the Pengjiakuang gold deposit, Mesozoic Jiaolai basin,

eastern China. International Geology Review, 45, 691-711. Zhang, L.C., Shen, Y.C., Liu, T.B., Zeng, Q.D., Li, G.M., Li, H.M., 2003b. 40Ar/39Ar and Rb-Sr isochron dating of the gold deposits on northern margin of the Jiaolai Basin, Shandong, China. Science in China (Series D), 46, 708-718. Zhang, X.O., Cawood, P.A., Wilde, S.A., Liu, R.Q., Song, H.L., Li, W., Snee, L.W., 2003c. Geology and timing of mineralization at the Cangshang gold deposit, north-western Jiaodong Peninsula, China. Mineralium Deposita, 38, 141-153. Zheng, J.P., Dai, H.K., 2018. Subduction and retreating of the western Pacific plate resulted in lithospheric mantle replacement and coupled basin-mountain respond 28

in the North China Craton. Science China Earth Sciences, 61, 406-424. Zheng, Y.F., Xu, Z., Zhao, Z.F., Dai, L.Q., 2018. Mesozoic mafic magmatism in North China: Implications for thinning and destruction of cratonic lithosphere. Science China Earth Sciences, 61, 353-385. Zhou, J.B., Han, W., Song, M.C., 2016. The exhumation of the Sulu Terrane and the forming of the Tancheng-Lujiang Fault: Evidence from detrital zircon U-Pb dating of the Mesozoic sediments of the Laiyang Basin, Central China. Acta Petrologica Sinica, 32, 1171-1181 (in Chinese with English abstract). Zhu, G., Wang, W., Gu, C.C., Zhang, S., Liu, C., 2016. Late Mesozoic evolution history of the Tan-Lu Fault Zone and its indication to destruction processes of the North China Craton. Acta Petrologica Sinica, 32, 935-949 (in Chinese with English abstract). Zhu, R.X., Chen, L., Wu, F.Y., Liu, J.L., 2011. Timing, scale and mechanism of the destruction of the North China Craton. Science China Earth Sciences, 54, 789-797. Zhu, R.X., Xu, Y.G., Zhu, G., Zhang, H.F., Xia, Q.K., Zheng, T.Y., 2012. Destruction of the North China Craton. Science China Earth Sciences, 55, 1565-1587. Zhu, R.X., Fan, H.R., Li, J.W., Meng, Q.R., Li, S.R., Zeng, Q.D., 2015. Decratonic gold deposits. Science China Earth Sciences, 58, 1523-1537. Zhu, R.X., Xu, Y.G., 2019. The subduction of the west Pacific plate and the destruction of the North China Craton. Science China Earth Sciences, 62, 1340-1350.

Figure captions Fig. 1. Regional geological map and distribution of gold deposits in the Jiaodong Peninsula (modified after Fan et al., 2003).

29

Fig. 2. Regional geological map of the Shijia gold deposit (modified from No. 6 Exploration Institute of Geology and Mineral Resources, Shandong, 2014).

Fig. 3 (a) Schematic geology of the Shijia gold deposit, (b) plan view of -400 m level, and (c) No. 84 prospecting line section (modified from the No. 6 Exploration Institute of Geology and Mineral Resources, Shandong, 2014).

Fig. 4. Rose diagrams showing the occurrence of the No. 1, 326, and 334 veins.

Fig. 5. Photographs of hand specimens and the microphotos showing the characteristics of orebodies, ores and mineral assemblages in the Shijia gold deposit. (a) Quartz-sulfide vein in the altered wall rock; (b) Disseminated pyrite in altered monzogranite; (c) Xenomorphic granular native gold in quartz vein; (d) Massive sulfide ore; (e) Brecciated quartz vein; (f) Comb and vug quartz; (g) Pyrite, galena, native gold, sphalerite and chalcopyrite in quartz vein; (h) Gold in fractures and margin of pyrite; (i) Pyrite coexisting with sphalerite and chalcopyrite; (j) Pyrite coexisting with sphalerite and chalcopyrite; (k) Pyrite coexisting with sphalerite and replaced by galena; (l) Sphalerite filled and replaced by chalcopyrite; (m) Sphalerite with disseminated solid solutions of chalcopyrite; (n) Chalcopyrite solid solutions along lattices in sphalerite; (o) Chalcopyrite solid solutions along growth zones in sphalerite; Au-native gold; Ccp-chalcopyrite; Gn-galena; Py-pyrite; Qz-quartz; Sp-sphalerite.

Fig. 6. Hydrothermal alteration characteristics of the Shijia gold deposit. (a) Narrow alteration halo on both sides of the quartz-sulfide vein (No. 36 exploration line at the -475 m level); (b) Potassic alteration occurring at the periphery of alteration zone and superimposed by silicification, sericitization and pyritization (No. 36 exploration line at the -475 m level); (c) Pervasive silicification and disseminated pyrite in altered monzogranite (No. 104 exploration line at the -240 m level); (d) Quartz vein in altered monzogranite (No. 52 exploration line at the -205 m level); (e) Beresitization of monzogranite with K-feldspar was replaced by quartz and sericite; (f) White calcite coexisting with dark green fluorite (No. 56 exploration line at the -205 m level); (g-h) Chloritization and epidotization in the altered monzogranite (No. 8 exploration line at the -555 m 30

level and No. 28 exploration line at the -435 m level); Cal-calcite; Chl-chlorite; Epi- epidote; Kf-K-feldspar; Py-pyrite; Qz-quartz; Ser-sericite; Sp-sphalerite.

Fig. 7. Typical mineral association and crosscutting relationship at different mineralization stages in the Shijia gold deposit. (a) The milky white quartz of stage Ⅰ fractures and cemented by the smoky gray quartz of stage Ⅱ; (b) Stage Ⅰ altered monzogranite fracture and cemented by the milky white quartz of stage Ⅱ; (c) The smoky gray quartz of stage Ⅱ cemented the altered granite and was in turn cut by the milky white quartz vein of stage Ⅲ (No. 24 exploration line at the -315 m level); (d) The milky white and smoky gray quartz of stage Ⅱ (No. 64 exploration line at the -475 m level); (e) The milky white quartz vein of stage Ⅲ cutting the smoky gray quartz vein of stage II and altered monzogranite of stage Ⅰ (No. 44 exploration line at the -555 m level); (f) Quartz-sulfide vein of stage Ⅱ enclosing the altered monzogranite of stage Ⅰ and cut by the milky white quartz vein of stage Ⅲ (No. 24 exploration line at the -395 m level); (g) Pink calcite veins of stage Ⅲ cutting altered monzogranite of stage Ⅰ (No. 0 exploration line at the -555 m level); (h) Calcite-fluorite vein of stage Ⅲ cutting the milky white quartz vein of stage Ⅱ (No. 56 exploration line at the -205 m level); Cal-calcite; Fl-fluorite; Gn- galena; Py-pyrite; Qz-quartz.

Fig. 8. Paragenesis of ore and gangue minerals of the Shijia gold deposit.

Fig. 9. Photographs showing the deformation and displacement of ore veins after mineralization. (a) Lens-like discontinuous distribution of the orebody caused by sinistral strike-slip shear (No. 80 exploration line at the -335 m level); (b) Deformed and fractured orebody (No. 16 exploration line at the -555 m level); (c) Sinistral strike-slip shear formed S-C fabric of quartz veins (No. 72 exploration line at the -435 m level); (d) Dextral strike-slip shear formed δ-type rotated porphyroclast of altered monzogranite (No. 92 exploration line at the -435 m level); (e) Sinistral strike-slip shear formed asymmetrical folds of quartz vein (No. 88 exploration line at the -435 m level); (f) Quartz veins and lamprophyre dyke were dislocated by two small strike-slip faults with different movement characteristics (No. 44 exploration line at the -395 m level); (g) Quartz vein dislocated by a NE-trending dextral strike-slip fault, resulting in discontinuous distribution of the quartz vein (No. 60 exploration line at the -240 m level); (h) Quartz vein and related alteration 31

zone were dislocated by an E-W-trending dextral strike-slip fault (No. 80 exploration line at the -395 m level).

Fig. 10. Photographs showing the crosscutting relationship between ore veins and different types of dykes. (a) Granite pegmatite dyke cut and dislocated by quartz vein, indicating granite pegmatite was predated the quartz vein (No. 28 exploration line at the -435 m level); (b) Granite pegmatite dyke cut and dislocated by quartz vein and the dyke was altered near the quartz vein, indicating granite pegmatite was predated the quartz vein (No. 24 exploration line at the -635 m level); (c-d) Quartz-sulfide vein cut by post-ore lamprophyre and diabase dykes, respectively (No. 36 and No. 28 exploration line at the -435 m level); (e) Later lamprophyre dyke distributing along the margin of quartz vein and showing a chilled border (No. 28 exploration line at the -475 m level); (f) Later diabase dyke with a chilled border at the margin of quartz vein (No. 48 exploration line at the -595 m level); (g) Quartz-sulfide vein cut dislocated by post-ore granite porphyry dyke (No. 0 exploration line at the -355 m level); (h-i) The pre-ore granite pegmatite cut by lamprophyre dyke, quartz vein and diabase dyke, respectively (No. 68 exploration line at the -515 m level and No. 56 exploration line at the -165 m level); (j) Earlier lamprophyre cut by diabase dyke (No. 76 exploration line at the -395 m level); (k) Diabase dyke cut by later granite porphyry dyke (No. 40 exploration line at the -435 m level).

Fig. 11. CL images for zircons from different types of dykes in the Shijia gold deposit.

Fig. 12. Zircon U-Pb Concordia diagrams and weighted mean age plots of dykes in the Shijia gold deposit.

Table captions Table1. U-Th-Pb isotope dating data of zircons from the dykes in the Shijia gold deposit.

Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this 32

paper.

Graphical Abstract

The crosscutting relationship between orebodies and mafic-felsic dykes shows that the sequence of their formation is granite pegmatite, orebodies, lamprophyre, diabase and granite porphyry. The emplacement ages obtained the LA-ICP-MS zircon U-Pb isotopic dating on granite pegmatite, lamprophyre, diabase, and granite porphyry are 129.7±1.6 Ma, 129.3±1.4 Ma, 128.3±1.3 Ma and 119.3±3.1 Ma, respectively, indicating that the mineralization age of the Shijia gold deposit is between 129.7 Ma and 129.3 Ma, at ca. 129 Ma.

Highlights:  The crosscutting relationship between the orebodies and mafic-felsic dykes are discribed.  The mineralization age of the Shijia gold deposit is ~129 Ma. 33

 Gold mineralization is related to the extension and thinning of the North China Craton.  Lamprophyre dykes may not have a direct genetic relationship with the Shijia gold deposits.

Table1 U-Th-Pb isotope dating data of zircons from the dykes in the Shijia gold deposit. Element Sampl e spot

contents/ppm Pb

Th

U

Isotope ratio

Th /U

206Pb

/238U

1σ

207Pb

/235U

1σ

Age/Ma 207Pb/ 206Pb

1σ

206Pb

1

207Pb

1

/238U

σ

/235U

σ

130.

8.

2

8

137.

8.

0

9

WJY-1Zr, Granite pegmatite 1

2

3

4

5

6

7

8

9 10

8

9

8

7

6

10

8

8

8 9

15

30

0.

0.02

0.0

0.13

0.0

5

5

51

1

004

7

098

19

38

0.

0.02

0.0

0.14

0.0

0

0

50

1

005

4

101

15

33

0.

0.02

0.0

0.13

0.0

9

6

47

0

004

8

124

13

26

0.

0.02

0.0

0.14

0.0

2

4

50

1

005

0

120

11

24

0.

0.02

0.0

0.13

0.0

1

1

46

0

005

5

112

21

39

0.

0.02

0.0

0.13

0.0

5

3

55

0

004

6

110

18

33

0.

0.02

0.0

0.12

0.0

5

3

56

0

004

7

108

16

31

0.

0.02

0.0

0.14

0.0

1

0

52

0

004

6

126

15

32

0.

0.02

0.0

0.12

0.0

1

5

47

0

005

8

101

14

38

0.

0.02

0.0

0.12

0.0

34

0.047

0.051

0.050

0.051

0.049

0.049

0.048

0.052

0.048 0.047

0.0

131.

038

5

0.0

132.

038

5

0.0

130.

049

0

0.0

131.

049

4

0.0

130.

047

2

0.0

130.

041

0

0.0

127.

050

1

0.0

128.

047

0

0.0

127.

042

2

0.0

130.

2 . 6 3 . 1 2 . 5 3 . 2 2 . 9 2 . 3 2 . 8 2 . 8 2 . 9 2

131. 3 132. 9 128. 8

1 1. 1 1 0. 7 1 0. 1

129.

9.

6

8

121.

9.

1

7

138. 7

1 1. 2

122.

9.

7

1

122.

9.

8

6

38

0

005

8

102

050

5

.

0

2

136.

8.

1

8

124.

8.

9

6

118.

8.

1

7

116.

7.

6

6

116.

7.

3

3

139.

9.

1

3

8 11

9

14

35

0.

0.02

0.0

0.14

0.0

2

1

41

0

004

3

099

0.051

0.0

128.

037

9

0.0

128.

041

9

0.0

128.

040

8

0.0

128.

031

4

0.0

128.

034

2

0.0

132.

039

8

0.0

136.

053

1

0.0

129.

034

5

0.0

128.

039

9

0.0

129.

030

8

0.0

128.

045

1

0.0

129.

046

4

2 . 8

HBY-1Zr, Lamprophyre 1

2

3

4

5

6

7

8

9

10

11

9

11

13

11

9

5

12

13

14

10

11

15

36

0.

0.02

0.0

0.13

0.0

1

7

41

0

004

1

096

24

41

0.

0.02

0.0

0.12

0.0

4

8

58

0

004

3

097

17

54

0.

0.02

0.0

0.12

0.0

7

7

32

0

004

2

084

22

43

0.

0.02

0.0

0.12

0.0

7

6

52

0

004

1

081

13

35

0.

0.02

0.0

0.14

0.0

7

4

39

1

005

7

105

10

21

0.

0.02

0.0

0.12

0.0

4

3

49

1

005

9

123

17

48

0.

0.02

0.0

0.14

0.0

4

8

36

0

004

1

092

23

51

0.

0.02

0.0

0.14

0.0

6

3

46

0

004

3

102

29

55

0.

0.02

0.0

0.14

0.0

1

6

52

0

005

4

086

22

40

0.

0.02

0.0

0.14

0.0

8

1

57

0

005

2

109

13

46

0.

0.02

0.0

0.13

0.0

1

8

28

0

005

5

113

35

0.048

0.045

0.044

0.044

0.051

0.045

0.050

0.051

0.051

0.053

0.050

2 . 6 2 . 6 2 . 5 2 . 4 2 . 9 3 . 1 2

123. 3

1 1. 0

134.

8.

3

2

135.

9.

3

1

136.

7.

3

7

134.

9.

7

7

3

128.

1

.

7

0.

. 3 2 . 5 2 . 8 2 . 9

2 12

13

14

15

7

7

7

9

12

27

0.

0.01

0.0

0.13

0.0

4

6

45

9

006

1

166

12

27

0.

0.02

0.0

0.13

0.0

1

1

45

0

006

1

144

12

29

0.

0.02

0.0

0.13

0.0

7

2

44

0

006

6

158

18

34

0.

0.02

0.0

0.13

0.0

1

8

52

0

005

1

128

16

33

0.

0.01

0.0

0.14

0.0

7

1

50

9

005

4

121

19

42

0.

0.02

0.0

0.13

0.0

5

2

46

0

004

4

112

33

0.

0.02

0.0

0.13

0.0

3

24

0

005

2

112

27

0.

0.01

0.0

0.13

0.0

1

35

9

005

4

118

14

33

0.

0.02

0.0

0.13

0.0

9

8

44

1

005

1

128

32

53

0.

0.01

0.0

0.12

0.0

2

2

60

9

004

6

108

11

26

0.

0.02

0.0

0.13

0.0

4

6

43

0

005

2

119

12

28

0.

0.02

0.0

0.13

0.0

3

1

44

0

005

4

110

0.052

0.048

0.049

0.046

0.0

123.

074

7

0.0

128.

057

8

0.0

129.

060

1

0.0

128.

043

5

0.0

123.

052

9

0.0

128.

042

0

0.0

126.

049

8

0.0

123.

052

6

0.0

133.

050

0

0.0

122.

045

8

0.0

127.

051

0

0.0

126.

047

9

3 . 7 3 . 5 3 . 5 3 . 0

1 125. 0 125. 4 129. 3 125. 3

1 4. 9 1 2. 9 1 4. 1 1 1. 5

SCBY-1Zr, Diabase 1

2

3

4

5

6

7

8

8

10

8

6

9

13

6

7

81

94

36

0.055

0.047

0.050

0.052

0.047

0.048

0.050

0.049

2 . 9 2 . 7 3 . 0 3 . 4 3 . 2 2 . 6 2 . 9 3 . 2

136. 9 127. 5 125. 8 127. 6 125. 3

1 0. 8 1 0. 0 1 0. 1 1 0. 6 1 1. 5

120.

9.

5

8

126. 2

1 0. 6

127.

9.

5

8

9

10

11

12

13

14

15

16

17

18

10

7

9

9

7

9

12

8

7

10

24

40

0.

0.02

0.0

0.14

0.0

7

1

62

0

005

7

118

18

29

0.

0.02

0.0

0.14

0.0

1

7

61

0

005

0

117

19

36

0.

0.02

0.0

0.14

0.0

4

7

53

1

004

8

120

22

37

0.

0.02

0.0

0.12

0.0

6

3

61

0

004

8

099

11

27

0.

0.02

0.0

0.13

0.0

8

8

42

1

004

6

107

17

33

0.

0.02

0.0

0.14

0.0

0

9

50

1

005

4

131

24

49

0.

0.02

0.0

0.13

0.0

9

3

50

0

004

4

087

16

32

0.

0.02

0.0

0.14

0.0

0

3

50

0

004

9

130

13

27

0.

0.02

0.0

0.13

0.0

5

9

48

0

005

8

128

25

39

0.

0.02

0.0

0.13

0.0

4

5

64

0

004

5

100

0.053

0.053

0.051

0.046

0.047

0.051

0.048

0.055

0.050

0.049

0.0

128.

048

1

0.0

130.

052

5

0.0

133.

043

2

0.0

128.

037

7

0.0

131.

040

7

0.0

133.

048

1

0.0

128.

035

4

0.0

128.

056

7

0.0

129.

054

0

0.0

126.

039

4

0.0

122.

040

7

0.0

117.

059

7

0.0

124.

3 . 1 3 . 1 2 . 5 2 . 5 2 . 7 3 . 1 2 . 6 2 . 7 3 . 1 2 . 7

138. 8 133. 3 140. 4

1 0. 4 1 0. 4 1 0. 6

122.

8.

6

9

129.

9.

4

6

136. 9

1 1. 6

127.

7.

4

8

140. 7 131. 0

1 1. 5 1 1. 5

129.

9.

0

0

125.

8.

4

2

SYBY-1Zr, Granite porphyry 1

2 3

16

9 13

10

50

2.

0.01

0.0

0.13

0.0

55

8

08

9

004

1

091

50

29

1.

0.01

0.0

0.12

0.0

4

1

73

8

005

4

122

65

43

1.

0.02

0.0

0.12

0.0

37

0.050

0.051 0.044

2 . 3 3 . 0 2

118. 6 114.

1 1. 0 9.

4

9

49

0

004

0

106

042

7

.

7

6

119.

8.

1

2

3 4

5

6

7

8

9

10

11

12

13

14

15

8

9

8

18

7

10

7

5

7

9

18

6

40

29

1.

0.01

0.0

0.12

0.0

2

8

35

8

004

4

091

44

34

1.

0.01

0.0

0.12

0.0

6

7

29

9

005

8

115

38

30

1.

0.01

0.0

0.11

0.0

8

1

29

9

004

9

114

97

58

1.

0.01

0.0

0.12

0.0

9

5

67

8

003

0

085

29

27

1.

0.01

0.0

0.12

0.0

3

3

01

9

005

7

098

49

40

1.

0.01

0.0

0.12

0.0

3

1

23

8

004

1

083

25

27

0.

0.01

0.0

0.13

0.0

9

6

94

8

005

2

127

41

15

2.

0.01

0.0

0.13

0.0

2

3

70

9

005

7

151

33

24

1.

0.01

0.0

0.13

0.0

9

6

38

9

005

5

132

60

28

2.

0.01

0.0

0.13

0.0

0

6

10

9

004

4

118

92

62

1.

0.01

0.0

0.12

0.0

7

8

48

9

004

1

079

23

25

0.

0.01

0.0

0.12

0.0

9

7

93

9

005

7

111

38

0.051

0.048

0.046

0.047

0.049

0.049

0.053

0.058

0.052

0.050

0.049

0.050

0.0

116.

043

3

0.0

122.

043

9

0.0

119.

050

6

0.0

117.

038

6

0.0

121.

047

7

0.0

116.

037

7

0.0

118.

056

1

0.0

119.

083

4

0.0

122.

054

8

0.0

122.

049

5

0.0

122.

035

3

0.0

121.

049

5

2 . 5 3 . 1 2 . 8 2 . 2 3 . 1 2 . 3 2 . 9 3 . 4 3 . 1 2 . 6 2 . 4 3 . 2

122. 4 114. 4

1 0. 4 1 0. 4

114.

7.

7

7

121.

8.

7

9

116.

7.

1

5

126. 2 130. 5 128. 6 127. 7

1 1. 4 1 3. 4 1 1. 8 1 1. 4

116.

7.

4

2

121. 1

1 0. 0

16

17

18

19

20

21

22

11

3

5

8

6

7

12

36

49

0.

0.01

0.0

0.12

0.0

6

1

75

8

004

6

091

17

10

1.

0.01

0.0

0.13

0.0

2

2

69

9

006

0

123

20

19

1.

0.01

0.0

0.12

0.0

6

4

06

9

005

3

158

46

26

1.

0.01

0.0

0.12

0.0

8

5

77

9

005

6

115

22

26

0.

0.01

0.0

0.13

0.0

5

2

86

9

006

4

108

41

23

1.

0.01

0.0

0.12

0.0

5

4

78

8

004

3

110

53

44

1.

0.01

0.0

0.12

0.0

7

7

20

9

003

0

090

39

0.049

0.050

0.047

0.050

0.053

0.048

0.046

0.0

117.

038

8

0.0

124.

065

5

0.0

120.

062

5

0.0

118.

050

5

0.0

122.

051

2

0.0

117.

049

0

0.0

129.

036

6

2 . 4 4 . 0 3 . 4 2 . 9 3 . 6 2 . 7 2 . 1

120.

8.

1

3

123. 8 118. 1 120. 7

1 1. 1 1 4. 2 1 0. 4

127.

9.

8

6

117.

9.

3

9

115.

8.

2

2