Adakite-like signature of porphyry granitoid stocks in the Meiduk and Parkam porphyry copper deposits,NE of Shahr-e-Babak,Kerman, Iran: Constrains on geochemistry

The Middle Miocene porphyry granitoid stocks of Meiduk and Parkam porphyry copper deposits are intruded in the north-western part of the Dehaj-Sarduiyeh volcano-sedimentary belt in the south-eastern extension of the Urumieh-Dukhtar Magmatic Arc (UDMA) in Iran. The porphyritic to microgranular granitoids are mainly consist of quartz diorite, granodiorite and diorite. The whole rock geochemical analyses of these rocks reveals sub-alkaline, calc-alkaline, meta-peraluminous and I-type characteristics. Their geochemical characteristics such as Al₂O₃ content of 13.51–17.05 wt%, high Sr concentration (mostly >400 ppm), low Yb (an average of 0.74 ppm) and Y (an average of 9.02 ppm) contents, strongly differentiated REE patterns (La/Yb ≥ 20), lack of Eu anomaly (Eu/Eu¹ ≥ 1) are indicative of adakitic signature. Their enrichment in low field strength elements (LFSE) and conspicuous negative anomalies for Nb, Ta and Ti are typical of subduction related magmas. Detailed petrological studies and geochemical data indicated that Meiduk and Parkam porphyry granitoids were derived from amphibole fractionation of hydrous melts at a depth of >40 km in a post-collisional tectonic setting.     

Carboniferous magmatism and mineralization in the area of the Fuxing Cu deposit,Eastern Tianshan,China: Evidence from zircon U–Pb ages,petrogeochemistry, and Sr–Nd–Hf–O isotopic compositions

The newly discovered Fuxing porphyry Cu deposit is located in the Dananhu–Tousuquan arc, adjacent to the Tuwu–Yandong Cu deposits of Eastern Tianshan, in the southern Central Asian Orogenic Belt. The Fuxing deposit is hosted by volcanic rocks (basalt and dacite) in the Early Carboniferous Qi'eshan Group and Carboniferous felsic intrusions (plagiogranite porphyry, monzogranite, and quartz diorite). New SIMS zircon U–Pb dating indicates that the plagiogranite porphyry and monzogranite emplaced at 332.1 ± 2.2 Ma and 328.4 ± 3.4 Ma, respectively. The basalts are characterized by low SiO₂ contents (47.47–54.90 wt.%), a lack of Eu anomalies, strong depletion of Na, Ta, and Ti elements but positive Sr, U, and Pb anomalies, high Y (20.8–28.2 ppm) and HREE concentrations (Yb = 2.23–3.06 ppm), and relatively low (La/Yb)_N (2.20–3.92) values; the dacite samples have high SiO₂ contents (66.13–76.93 wt.%), clearly negative Eu anomalies, high Mg^# values (36–51), and high Y (41.8–54.9 ppm) and Yb (5.76–8.98 ppm) concentrations. The basalts and dacites exhibit similar signatures as normal arc rocks, and were considered to be derived from partial melting of mantle-wedge peridotite that was previously metasomatized by slab melts. In contrast, the plagiogranite porphyry, monzogranite, and quartz diorite show the same geochemical affinity with modern adakites, which are characterized by high SiO₂ contents (67.55–79.00 wt.%), minor negative to positive Eu anomalies, strong depletion of heavy rare earth elements (Yb = 0.17–1.19 ppm) and Y (1.86–10.1 ppm), positive K, Rb, Sr, and Ba but negative Nb, Ta, Th, and Ti anomalies, and high (La/Yb)_N ratios and Mg^# values. Moreover, these adakitic felsic intrusions display relatively high positive zircon ε_Hf(t) values (+ 11.4 to + 18.3), low ⁸⁷Sr/⁸⁶Sr (0.706080–0.711239), high ¹⁴³Nd/¹⁴⁴Nd (0.512692–0.512922) ratios, and consistent zircon δ¹⁸O values (4.41‰–5.48‰), suggesting that their parental magma were most likely derived from partial melting of the subducted oceanic crust followed by mantle peridotite interaction. Based on the whole-rock geochemical and Sr–Nd–Hf–O isotopic data, as well as detailed petrographic analyses, we further suggest that the Fuxing igneous rocks and associated porphyry Cu mineralization were generated by the northward subduction of the paleo-Tianshan oceanic plate beneath the Dananhu–Tousuquan island arc during the Early Carboniferous.     

Petrogenesis of ore-forming and pre/post-ore granitoids from the Kounrad,Borly and Sayak porphyry/skarn Cu deposits,Central Kazakhstan

Ore-forming porphyries and barren granitoids from porphyry Cu deposits differ in many ways, particularly with respect to their adakitic affinity and calc-alkaline characteristics. In this study, zircon U–Pb and molybdenite Re–Os dating, whole rock geochemistry, whole rock Sr–Nd–Pb and zircon O–Hf isotopic analyses were carried out on the ore-forming granitoids from the Kounrad, Borly and Sayak deposits, and also on pre-ore and post-ore granitoids in adjacent regions of Central Kazakhstan. Geochronology results indicate that pre-ore magmatism occurred in the Late Devonian to Early Carboniferous (361.3–339.4 Ma), followed by large scale Cu mineralization (325.0–327.3 Ma at Kounrad, 311.4–315.2 Ma at Borly and 309.5–311.4 Ma at Sayak), and finally, emplacement of the Late Carboniferous post-ore barren granitoids (305.0 Ma). The geochemistry of these rocks is consistent with calc-alkaline arc magmatism characterized by strong depletions in Nb, Ta and Ti and enrichments in light rare earth elements and large ion lithophile elements, suggesting a supra-subduction zone setting. However, the ore-forming rocks at Kounrad and Sayak show adakitic characteristics with high Sr (517.5–785.3 ppm), Sr/Y (50.60–79.26), (La/Yb)_N (9.37–19.62) but low Y (6.94–11.54 ppm) and Yb (0.57–1.07 ppm), whereas ore-forming rocks at Borly and barren rocks from northwest of Borly and Sayak have normal arc magma geochemical features. The Sr–Nd–Hf–O isotopic compositions show three different signatures: (1) Sayak granitoids have very young juvenile lower crust-derived compositions ((⁸⁷Sr/⁸⁶Sr)_i = 0.70384 to 0.70451, ɛ_Nd (t) = + 4.9 to + 6.0; T_DM2 (Nd) = 580 to 670 Ma, ɛ_Hf (t) = + 11.3 to + 15.5; T_DM^C (Hf) = 330 to 600 Ma, δ¹⁸O = 6.0 to 8.1‰), and were probably generated from depleted mantle-derived magma with 5–15% sediment melt addition in the magma source; (2) the Kt-1 granite from northwest of Sayak shows extremely enriched Sr–Nd isotopic compositions ((⁸⁷Sr/⁸⁶Sr)_i = 0.71050, ɛ_Nd (t) = − 7.8, T_DM2 (Nd) = 1700 Ma), likely derived from partial melting of ancient continental crust; (3) other granitoids have transitional Sr–Nd compositions between the Sayak and Kt-1 samples, indicating a juvenile lower crust source with the addition of 10–30% of ancient crustal material. The pre-ore magmatism was probably related to partial melting of juvenile lower crust due to northward subduction of the Junggar–Balkhash Ocean, whereas the ore-forming adakitic rocks at Aktogai, Kounrad and Sayak formed by partial melting of thickened lower crust which subsequently delaminated. The ore-forming rocks at Borly, and the later post-ore barren granites, formed by partial melting of juvenile lower crust with normal thickness. This tectonic setting supports the existence of an Andean-type magmatic arc in the Devonian to the Late Carboniferous, resulting from the subduction of the Junggar–Balkhash oceanic plate. The link between whole rock geochemistry and scale of mineralization suggests a higher metallogenic potential for adakitic rocks than for normal arc magmatism.     

Significance of adakites in petrogenesis of early Silurian magmatism at the Yudai copper deposit in the Kalatag district,NW China

Yudai is a newly discovered copper deposit associated with a porphyritic quartz diorite, in the Kalatag district of the eastern Tianshan, China. SHRIMP U-Pb dating of zircons from the diorite yielded an age of 432 ± 3 Ma. The diorite is peraluminous (ASI = 0.98–1.10), calc-alkaline to tholeiitic with high Al₂O₃ of 16.6–17.7 wt% and Mg^# of 57.4–67.4. Trace element characteristics of the diorite show it is enriched in Ba, K and Sr, and depleted in Nb, Ta, Ti, with a positive Eu anomaly and high Sr/Y and La/Yb ratios. This diorite has positive ε_Nd(t) values ranging from 6.2 to 8.4 with low initial ⁸⁷Sr/⁸⁶Sr ratios of 0.704336 to 0.704450. These geochemical and isotopic characteristics indicate that the adakite-like diorite, associated with the copper mineralization, was emplaced in an island arc setting and resulted from partial melting of subducted oceanic plate in a mantle wedge.     

Geochronology of the Hongniu-Hongshan porphyry and skarn Cu deposit,northwestern Yunnan province,China: Implications for mineralization of the Zhongdian arc

The Hongniu-Hongshan porphyry and skarn copper deposit is located in the Triassic Zhongdian island arc, northwestern Yunnan province, China. Single-zircon laser ablation inductively coupled plasma mass spectrometry U–Pb dating suggests that the diorite porphyry and the quartz monzonite porphyry in the deposit area formed at 200 Ma and 77 Ma, respectively. A Re–Os isotopic date of molybdenite from the ore is 78.9 Ma, which indicates that in addition to the known Triassic Cu–(Au) porphyry systems, a Late Cretaceous porphyry Cu–Mo mineralization event also exists in the Zhongdian arc. The quartz monzonite porphyry shows characteristics of a magnetite series intrusion, with a high concentration of Al, K, Rb, Ba, and Pb, low amount of Ta, Ti, Y, and Yb, and a high ratio of Sr/Y (average 26.42). The Cretaceous porphyry also shows a strong fractionation between light and heavy rare earth elements (average (La/Yb)_N 37.9), which is similar to those of the Triassic subduction-related diorite porphyry in the Hongniu-Hongshan deposit and the porphyry hosting the Pulang copper deposit. However, in contrast to the older intrusions, the quartz monzonite porphyry contains higher concentrations of large ion lithophile elements and Co, and lesser Sr and Zr. Therefore, whereas the Triassic porphyry Cu–(Au) mineralization is related to slab subduction slab in an arc setting, the quartz monzonite porphyry in the Hongniu-Hongshan deposit formed by the remelting of the residual oceanic slab combined with contributions from subduction-modified arc lithosphere and continental crust, which provided the metals for the Late Cretaceous mineralization.     

Magma mixing origin for the Aolunhua porphyry related to Mo–Cu mineralization,eastern Central Asian Orogenic Belt

Many Cu–Mo–Au deposits are considered to be related to adakitic porphyries formed in non-arc settings, e.g., in collisional orogenic zones and intra-plate environments, but their genesis is still under discussion. The Aolunhua porphyry complex and its related Mo–Cu deposit from the eastern Central Asian Orogenic Belt (CAOB) provide important insights into this issue. The porphyries are characterized by high Sr (496–705 ppm) and Sr/Y and La/Yb ratios similar to those of typical adakitic rocks, and low I_Sr ratios (0.7049–0.7052) and positive ε_Nd(t) (+ 0.5 to + 1.4) and ε_Hf(t) (+ 3.5 to + 9.8) values. These features, along with the occurrence of mafic microgranular enclaves (MMEs), compositional and textural disequilibrium of plagioclase phenocrysts and relatively high Mg# values (45–52), indicate that they were derived from mixing of felsic magma from partial melting of a juvenile arc-type lower crust and mafic magma from a lithospheric mantle previously metasomatized by subduction zone fluids/melts. High Sr/Y and La/Yb ratios are indicative of contribution from enriched mantle-derived materials (with high LILEs; e.g., Sr, La), which were strengthened by subsequent fractionation of ferromagnesian phases such as pyroxene and hornblende. MMEs hosted by the ore-bearing porphyry have zircon U–Pb ages of ca. 132 Ma, similar to those of the host rocks. The enclaves have elevated Mg^# (56–63), LILEs (e.g., Sr = 660–891 ppm), LREE (La_N = 68–150, (La/Sm)_N = 3.0–4.0, (La/Yb)_N = 12.0–19.6) and ratios of radiogenic isotopes of Nd- and Hf (ε_Nd = + 0.7 to + 1.6; ε_Hf = + 3.3 to + 10.9), suggesting that their parental magmas were derived from the metasomatized mantle source. The Mo–Cu mineralization was probably related to the high water content, high oxygen and sulfur fugacity of hybrid magma. Formation of the adakitic porphyries and related Mo–Cu deposits of the eastern CAOB could be related to the Early Cretaceous lithospheric extension, caused by the subduction of the Paleo-Pacific plate and its induced reactivation of juvenile arc-type lower crust.     

Magmatic evolution of the Tuwu–Yandong porphyry Cu belt,NW China: Constraints from geochronology,geochemistry and Sr–Nd–Hf isotopes

The Tuwu–Yandong porphyry Cu belt is located in the Eastern Tianshan mountains in the eastern Central Asian Orogenic Belt. Petrochemical and geochronological data for intrusive and volcanic rocks from the Tuwu and Yandong deposits are combined with previous studies to provide constraints on their petrogenesis and tectonic affinity. New LA–ICP–MS zircon U–Pb ages of 348.3 ± 6.0 Ma, 339.3 ± 2.2 Ma, 323.6 ± 2.5 Ma and 324.1 ± 2.3 Ma have been attained from intrusive units associated with the deposits, including diorite, plagiogranite porphyry, quartz albite porphyry and quartz porphyry, respectively. The basalt and andesite, which host part of the Cu mineralization, are tholeiitic with high Al₂O₃, Cr, Ni and low TiO₂ contents, enriched LREEs and negative HFSE (Nb, Ta, Zr, Ti) anomalies consistent with arc magmas. Diorites are characterized by low SiO₂ content but high MgO, Cr and Ni contents, similar to those of high-Mg andesites. The parental magma of the basalt, andesite and diorite is interpreted to have been derived from partial melting of mantle-wedge peridotite that was previously metasomatized by slab melts. The ore-bearing plagiogranite porphyry is characterized by high Na₂O, Sr, Cr and Ni contents, low Y and Yb contents, low Na₂O/K₂O ratios and high Sr/Y ratios and high Mg#, suggesting an adakitic affinity. The high ε_Nd(t) (5.02–9.16), low I_Sr (0.703219–0.704281) and high ε_Hf(t) (8.55–12.99) of the plagiogranite porphyry suggest they were derived by a partial melting of the subducted oceanic crust followed by adakitic melt-mantle peridotite interaction. The quartz albite porphyry and quartz porphyry are characterized by similar Sr–Nd–Hf isotope but lower Mg# and whole-rock (La/Yb)_N ratios to the plagiogranite porphyry, suggesting they were derived from juvenile lower crust, and negative Eu anomalies suggest fractionation of plagioclase. We propose that a flat subduction that started ca. 340 Ma and resulted in formation of the adakitic plagiogranite porphyry after a period of “steady” subduction, and experienced slab rollback at around 323 Ma.     

Delineation of the ca. 2.7 Ga TTG gneisses in the Zanhuang Complex,North China Craton and its geological implications

Through detailed studies we have delineated a suite of banded TTG gneisses from the Zanhuang Complex. The protolith of the gneisses, predominantly tonalite, has undergone intensive metamorphism, deformation and anatexis and in a banded structure is intimately associated with melanocratic dioritic gneiss and leucocratic trondhjemitic veins. SHRIMP Zircon U–Pb data show that the tonalite was formed ca. 2692 ± 12 Ma ago. The tonalitic gneiss has the features of high SiO₂ (67.76–73.31%), high Al₂O₃ (14.38–15.83%), rich in Na₂O (4.48–5.07%) and poor in K₂O (0.77–1.93%). The gneiss is strongly fractioned in REE ((La/Yb)_N = 12.02–24.65) and shows a weak positive Eu anomaly (Eu/Eu^* = 1.05–1.64). It has high contents of Ba (199–588 ppm) and Sr (200–408 ppm), low contents of Yb (0.32–1.00 ppm) and Y (3.41–10.3 ppm) with high Sr/Y ratios (21.77–96.77) and depletion in HFSE Nb, Ta and Ti. These characteristics are similar to those of the high-Si adakitic rocks. The melanocratic dioritic gneiss has low SiO₂ (59.81%), high MgO (6.34%), high Al₂O₃ (14.02%) contents, rich in Na₂O (3.7%) and poor in K₂O (1.79%), with high Mg index (Mg^# = 67). REE and trace elements are on the whole similar to that of the tonalitic gneiss, but compatible element abundances V (116 ppm), Cr (249 ppm), Co (37 ppm) and Ni (179 ppm) are higher. The leucocratic felsic bands (approximating trondhjemite in composition) have major oxides similar to that of the TTG gneisses but the REE and compatible elements are extremely low, which are indicative of the products of anatexis. The tonalitic gneiss has positive ε_Nd(t) (2.37–3.29) and low initial Sr (0.69719–0.70068) values with depleted mantle Nd model age of ca. 2.8 Ga, suggesting its generation from partial melting of mantle-derived juvenile crust. The dioritic gneiss was also derived from subduction environment, but has undergone significant metasomatism of mantle wedge. The delineation of the ca. 2.7 Ga TTG gneisses in the Zanhuang Complex further proves that the North China Craton experienced large-scale continental crustal accretion in early Neoarchean, and gives new constraints on the subdivision of the early blocks and greenstone belts of the craton.     

Multi-stage granitic magmatism during exhumation of subducted continental lithosphere: Evidence from the Wulong pluton,South Qinling

Detailed petrology and zircon U–Pb dating data indicate that the Wulong pluton is a zoned granitic intrusive, formed from successive increments of magmas. An age range of at least 30 Ma is recorded from the 225–235 Ma quartz diorite on the pluton margin, the ca. 218 Ma granodiorite in the intermediate zone, and the ca. 207 Ma monzogranite at the pluton center. All the granitoids display evolved Sr–Nd–Pb isotopic compositions, with ⁸⁷Sr/⁸⁶Sr(i) of 0.7044–0.7062, unradiogenic Nd (ε_Nd(t) values of − 6.1 to − 3.0, Nd model ages of 1.1–1.3 Ga, and moderately radiogenic Pb compositions (²⁰⁶Pb/²⁰⁴Pb(i) = 17.500–17.872, ²⁰⁷Pb/²⁰⁴Pb(i) = 15.513–15.549, ²⁰⁸Pb/²⁰⁴Pb(i) = 37.743–38.001), in combination with variations in zircon Hf isotopic compositions (with ε_Hf(t) values in each stage span 12 units) and the Hf isotopic model ages of 800–1600 Ma. These features suggest that the granitoids might have been derived from the reworking of an old lower crust, mixed with Paleozoic and Proterozoic materials. The rocks also display an adakitic affinity with Sr (479–973 ppm), high Sr/Y ratios (mostly > 60) and negligible Eu anomalies (Eu/Eu* = 0.78–0.97) but low Rb/Sr ratios, low Y (4.6–17 ppm), HREE (Yb = 0.95–1.7 ppm), Yb/Lu (6–7) and Dy/Yb (1.9–2.4) ratios, suggesting the absence of plagioclase and presence of garnet + amphibole in their residue. Considering a large gap among their crystallization ages, we propose that the geochemical evolution from pluton margin to center was controlled mainly by melting conditions and source compositions rather than fractional crystallization. Mafic enclaves that were hosted in the quartz diorite and granodiorite are mainly syenogabbroic to syenodioritic in composition, and are metaluminous and enriched in LREE and LILEs, but are depleted in HFSE, and display an evolved Sr–Nd–Pb isotopic composition, suggesting that they may have been derived from the partial melting of an enriched mantle lithosphere, which was metasomatized by adakitic melts and fluids from a subducted continental crust.In combination with the results of the Triassic ultra-high pressure metamorphic rocks in the Dabie orogenic belt, we apply a model involving the exhumation of subducted continental crust to explain the formation of the Wulong pluton. At the first stage, a dense and refractory mafic lower crust that was trapped at mantle depth by continental subduction witnessed melting under high temperature conditions to produce the quartz diorite magma, characterized by low SiO₂ (60.65–63.98 wt.%) and high TiO₂ (0.39–0.86 wt.%). The magma subsequently interacted with mantle peridotite, leading to high Mg# (57–67) and the metasomatism of the overriding mantle wedge. At the second stage, an asthenosphere upwelling that was probably caused by slab break-off at ca. 220 Ma melted the enriched sub-continental lithospheric mantle (SCLM) to produce mafic magmas, represented by the mafic enclaves that are hosted in the quartz and granodiorite, resulting in the partial melting of the shallower subducted crust, and generating the granodiorite that is distinguished by high SiO₂ (69.16–70.82 wt.%), high Al₂O₃ (15.33–16.22 wt.%) and A/CNK values (mostly > 1.05). At the third stage, the final collapse of the Triassic Qinling–Dabie Orogenic Belt at ca. 215–205 Ma caused extensive partial melting of the thickened orogenic lower crust to produce the monzogranite, which is characterized by high SiO₂ (67.68–70.29 wt.%), low TiO₂ (mostly < 0.35 wt.%) and high Sr/Y ratios of 86–151.     

Gold-hosting high Ba-Sr granitoids in the Xincheng gold deposit,Jiaodong Peninsula,East China: Petrogenesis and tectonic setting

The Xincheng deposit is the only large gold deposit with a proven reserve of >200 t gold hosted by the Early Cretaceous granitoids in northwest Jiaodong Peninsula, East China. The granitoids hosting this ore deposit comprise an inner medium- to fine-grained quartz monzonite and an outer medium- to coarse-grained monzogranite with distinctive K-feldspar megacrysts. LA–ICP–MS zircon dating yields U–Pb ages of 128 ± 1 to 132 ± 1 Ma and 127 ± 2 to 129 ± 1 Ma, for the quartz monzonite and the monzogranite, respectively. The Early Cretaceous ages obtained in our study are comparable with the 126–130 Ma age range reported for the Guojialing granitic suite. The monzogranites, typical high Ba–Sr granites, possess high SiO₂ (70.89–73.35%), K₂O (3.85–4.32%), total alkalis (K₂O + Na₂O = 8.08–8.68%), Sr (634–888 ppm), Ba (1395–2111 ppm) and LREE (59.43–145.88), with low HREE and HFSE contents and insignificant Eu anomalies. The rocks display markedly high Sr/Y (114–297) and (La/Yb)_N (20–79) ratios. They have low MgO (0.23–0.62%), Cr (0.4–8.33 ppm) and Ni (0.47–2.92 ppm) contents. The typical high Ba–Sr signatures of the outer acidic monzogranites are also shared by the inner intermediate-acidic quartz monzonites, with a relatively higher abundance of these elements. The plagioclases in the quartz monzonites and monzogranites are oligoclase–andesine with An contents of 11.7–44.5%, and oligoclase with An contents of 12.9–29.3%, respectively, which both show the reverse zoning texture. The quartz monzonites have zircon ε_Hf(t) values of −21.3 to −13.9 (average −18.7), which are less negative and show larger variations than those of the monzogranites (ε_Hf(t) = −24.7 to −18.1, average −19.5). Detailed elemental, mineralogical and isotopic data suggest that the high Ba–Sr quartz monzonites and monzogranites were most likely generated by partial melting of the basement rocks of the Jiaobei terrane accompanied by crustal assimilation, with minor addition of the intermediate magma derived from the partial melting of juvenile mafic lower crust formed by the earlier underplating of mantle magma, and the quartz monzonites may represent the path of intermediate magma inputting into felsic magma. In combination with previous investigations, we suggest subduction of the paleo-Pacific slab beneath the North China Craton (NCC) and associated asthenosphere upwelling were most likely the mechanism associated with the generation of the high Ba–Sr granites.     

Geology,geochronology and geochemistry of granitic intrusions and the related ores at the Hongshan Cu-polymetallic deposit: Insights into the Late Cretaceous post-collisional porphyry-related mineralization systems in the southern Yidun arc,SW China

The Hongshan Cu-polymetallic deposit is located in the southern Yidun arc in southwestern China, where both subduction-related (Late Triassic) and post-collisional (Late Cretaceous) porphyry–skarn–epithermal mineralization systems have been previously recognized. In this study, two distinct magmatic events, represented by diorite porphyry and quartz monzonite porphyry, have been revealed in the Hongshan deposit, with zircon SHRIMP U–Pb ages of 214 ± 2 Ma and 73.4 ± 0.7 Ma, respectively. The 73 Ma age is comparable to the Re–Os ages of 77 to 80 Ma of ore minerals from the Hongshan deposit, indicating that the mineralization is related to the Late Cretaceous quartz monzonite porphyries rather than Late Triassic diorite porphyries. The Late Triassic diorite porphyries belong to the high-K calc-alkaline series and show arc magmatic geochemical characteristics such as enrichment in Rb, Ba, Th and U and depletion in HFSEs, indicating that they were formed during the westward subduction of the Garzê–Litang Ocean. In contrast, the Late Cretaceous quartz monzonite porphyries show shoshonitic I-type geochemical characteristics, with high SiO₂, K₂O, LILE, low HREE, Y and Yb contents, and high LREE/HREE and La/Yb ratios. These geochemical characteristics, together with the Sr–Nd–Pb isotopic compositions (average (⁸⁷Sr/⁸⁶Sr)_i = 0.7085; ε_Nd(t) = − 6.0; ²⁰⁶Pb/²⁰⁴Pb = 19.064, ²⁰⁷Pb/²⁰⁴Pb = 15.738, ²⁰⁸Pb/²⁰⁴Pb = 39.733) suggest that the quartz monzonite porphyries originated from the partial melting of the ancient lower crust in response to underplating of mafic magma from subduction metasomatized mantle lithosphere, possibly triggered by regional extension in the post-collisional tectonic stage. The S isotopic compositions (δ³⁴S_V-CDT = 3.81‰ to 5.80‰) and Pb isotopic compositions (²⁰⁶Pb/²⁰⁴Pb = 18.014 to 18.809, ²⁰⁷Pb/²⁰⁴Pb = 15.550 to 15.785, and ²⁰⁸Pb/²⁰⁴Pb = 38.057 to 39.468) of ore sulfides indicate that the sulfur and metals were derived from mixed mantle and crustal sources. It is proposed that although the Late Triassic magmatic event is not directly related to mineralization, it contributed to the Late Cretaceous mineralization system through the storage of large amounts of sulfur and metals as well as water in the cumulate zone in the mantle lithosphere through subduction metasomatism. Re-melting of the mantle lithosphere including the hydrous cumulate zone and ancient lower crust during the post-collisional stage produced fertile magmas, which ascended to shallow depths to form quartz monzonite porphyries. Hydrothermal fluids released from the intrusions resulted in porphyry-type Mo–Cu ores in and near the intrusions, skarn-type Cu–Mo ores in the country rocks above the intrusions, and hydrothermal Pb–Zn ores in the periphery.     

Transition from shoshonitic to adakitic magmatism in the eastern Pontides,NE Turkey: Implications for slab window melting

The formation of the eastern Pontides orogenic belt has been widely assigned to a northward subduction of the Neotethyan oceanic slab during the late Mesozoic–Cenozoic. Here we provide an alternate model based on new geological, geochemical and isotopic data. The magmatic activity in the far south of the belt started in the early Campanian with shoshonitic trachyandesites and associated pyroclastics. This sequence is covered by the late Campanian–early Maastrichtian reefal limestones and another stage of high-K volcanism represented by analcimized leucite-rich ultrapotassic rocks of the Maastrichtian–early Paleocene (?) ages. The shoshonitic and ultrapotassic rocks, with K₂O contents ranging from 0.26 to 6.95 wt.%, display broadly similar rare earth and multi-element distribution patterns. Both rock types are enriched in LILE and LREE and depleted in HFSE (Nb, Ta and Ti), suggesting a subduction-enriched mantle source for the magma generation. Subsequently, during the late Paleocene, a stage of acidic magmatism (SiO₂ of 53.25–73.61 wt.%) that shows adakitic geochemical characteristics including high Sr/Y (46–416) and La/Yb (11–51) and low Y (2.6–12.2 ppm), is documented characterized by melting of a mafic source such as the MORB crust with garnet in the residue. The adakitic magmatism began at ~ 56 Ma and migrated toward the north through time, culminating with porphyritic andesites (~ 47 Ma) that were emplaced in the Gumushane–Bayburt line and its vicinity. North of this line, coeval magmas show typical calc-alkaline nature and continued to develop toward further north until the middle to late Eocene. Based on the spatial and temporal variations in the magmas generated in the eastern Pontides orogenic belt, we propose a new geodynamic model to explain the tectonomagmatic evolution of these rocks and correlate the adakitic magmatism to ridge subduction and slab window process within a south-dipping subduction zone. Our model is in contrast to the previous proposals which envisage partial melting or delamination of thickened lower continental crust due to the collision in the south during the Paleocene–Eocene.     

Petrogenesis and geodynamic evolution of the Kajan Neogene subvolcanic rocks,Nain, Central Iran

Kajan subvolcanic rocks in the Urumieh–Dokhtar magmatic arc (UDMA), Central Iran, form a Late Miocene-Pliocene shallow-level intrusion. These subvolcanics correspond to a variety of intermediate and felsic rocks, comprising quartz diorite, quartz monzodiorite, tonalite and granite. These lithologies are medium-K calc-alkaline, with SiO₂ (wt.%) varying from 52% (wt.%) to 75 (wt.%). The major element chemical data also show that MgO, CaO, TiO₂, P₂O₅, MnO, Al₂O₃ and Fe₂O₃ define linear trends with negative slopes against SiO₂, whilst Na₂O and K₂O are positively correlated with silica. Contents of incompatible trace elements (e.g. Ba, Rb, Nb, La and Zr) become higher with increasing SiO₂, whereas Sr shows an opposite behaviour. Chondrite-normalized multi-element patterns show enrichment in LILE relative to HFSE and troughs in Nb, P and Ti. These observations are typical of subduction related magmas that formed in an active continental margin. The Kajan rocks show a strong affinity with calc-alkaline arc magmas, confirmed by REE fractionation (La_N/Yb_N = 4.5–6.4) with moderate HREE fractionation (Sm_N/Yb_N = 1.08–1.57). The negative Eu anomaly (Eu/Eu* <1), the low to moderate Sr content (< 400 ppm) and the Dy/Yb values reflect plagioclase and hornblende (+- clinopyroxene) fractionation from a calc-alkaline melt Whole–rock Sr and Nd isotope analyses show that the ⁸⁷Sr/⁸⁶Sr initial ratios vary from 0.704432 to 0.705989, and the ¹⁴³Nd/¹⁴⁴Nd initial ratios go from 0.512722 to 0.512813. All the studied samples have similar Sr-Nd isotopes, indicating an origin from a similar source, with granite samples that has more radiogenic Sr and low radiogenic Nd isotopes, suggesting a minor interaction with upper crust during magma ascent. The Kajan subvolcanic rocks plot within the depleted mantle quadrant of the conventional Sr-Nd isotope diagram, a compositional region corresponding to mantle-derived igneous rocks.     

Geochemical constraints on the petrogenesis of the Paleozoic granitoids of the Sierra de San Luis,Sierras Pampeanas,Argentina

The Paleozoic granitoids of the Sierra de San Luis comprise the Ordovician tonalite suite (OTS; metaluminous to mildly peraluminous calcic tonalite–granodiorites) and granodiorite–granite suite (OGGS; peraluminous calcic to calc-alkaline granodiorite–monzogranites), as well as the Devonian granite suite (DGS; peraluminous alkali-calcic monzogranites) and monzonite–granite suite (DMGS; metaluminous alkali-calcic quartz monzonite–monzogranite ± granodiorite, mildly peraluminous alkalicalcic monzogranites). The OTS has relatively high K₂O, CaO, and Yb_N and low Cr, Ni, Ba, Sr, Rb/Sr, Sr/Y, and (La/Yb)_N, as well as negative Eu/Eu¹, high ⁸⁷Sr/⁸⁶Sr (0.70850–0.71114), and unradiogenic ε_Nd(470Ma) (−5.3 to −6.0), which preclude an origin of variably fractionated mantle melts and favour a mafic lower crustal source. The OGGS consists of two granitoids: (1) high-temperature characterized by low Al₂O₃/TiO₂, Rb/Sr, and (La/Yb)_N, a smooth negative Eu/Eu¹, and relatively high CaO and (2) low-temperature with high Al₂O₃/TiO₂ and Rb/Sr, low CaO, (La/Yb)_N, and Sr/Y, and negative Eu/Eu¹. Melting of metagreywackes at pressures below 10 kbar with a variable supply of water could account for the chemistry of the high-T OGGS, whereas dehydration melting of biotite-bearing metasedimentary sources at low pressures is proposed for the low temperature OGGS. Melting of crustal sources relates to a contemporaneous mafic magmatism.Devonian magmatism is characterized by high Ba, Sr, K₂O, Na₂O, Sr/Y, and (La/Yb)_N. Sources for the DGS include metasedimentary or metatonalitic protoliths. Biotite dehydration melting triggered by the addition of heat, supplied by mantle-derived magmas, is proposed. High Ba, Sr, LREE, MgO, Cr, Ni, Zr, and V of the monzonites suggest an enriched lithospheric mantle source. Low Yb and Y and high Sr and (La/Yb)_N indicate a garnet-rich residual assemblage (P ⩾ 10 kbar). Melts for the peraluminous rocks may have derived from a metasedimentary or metaigneous source at lower pressures in a process dominated by biotite consumption and plagioclase in the residue.The Ordovician granitoids are synkinematic with compressive deformation related to the early stages of Famatinian convergence. The Devonian magmatism is synkinematic with a system of shear zones that were active during the Achalian cycle.     

Long-lived,stationary magmatism and pulsed porphyry systems during Tethyan subduction to post-collision evolution in the southernmost Lesser Caucasus,Armenia and Nakhitchevan

The composite Meghri–Ordubad and Bargushat plutons of the Zangezur–Ordubad region in the southernmost Lesser Caucasus consist of successive Eocene to Pliocene magmatic pulses, and host two stages of porphyry Cu–Mo deposits. New high-precision TIMS U–Pb zircon ages confirm the magmatic sequence recognized by previous Rb–Sr isochron and whole-rock K–Ar dating. A 44.03 ± 0.02 Ma-old granite and a 48.99 ± 0.07 Ma-old granodiorite belong to an initial Eocene magmatic pulse, which is coeval with the first stage of porphyry Cu–Mo formation at Agarak, Hanqasar, Aygedzor and Dastakert. A subsequent Oligocene magmatic pulse was constrained by U–Pb zircon ages at 31.82 ± 0.02 Ma and 33.49 ± 0.02 Ma for a monzonite and a gabbro, and a late Miocene porphyritic granodioritic and granitic pulse yielded ages between 22.46 ± 0.02 Ma and 22.22 ± 0.01 Ma, respectively. The Oligo-Miocene magmatic evolution broadly coincides with the second porphyry-Cu–Mo ore deposit stage, including the major Kadjaran deposit at 26–27 Ma.Primitive mantle-normalized spider diagrams with negative Nb, Ta and Ti anomalies support a subduction-like nature for all Cenozoic magmatic rocks. Eocene magmatic rocks have a normal arc, calc-alkaline to high-K calc-alkaline composition, early Oligocene magmatic rocks a high-K calc-alkaline to shoshonitic composition, and late Oligocene to Mio-Pliocene rocks are adakitic and have a calc-alkaline to high-K calc-alkaline composition. Radiogenic isotopes reveal a mantle-dominated magmatic source, with the mantle component becoming more predominant during the Neogene. Trace element ratio and concentration patterns (Dy/Yb, Sr/Y, La/Yb, Eu/Eu*, Y contents) correlate with the age of the magmatic rocks. They reveal combined amphibole and plagioclase fractionation during the Eocene and the early Oligocene, and amphibole fractionation in the absence of plagioclase during the late Oligocene and the Mio-Pliocene, consistent with Eocene to Pliocene progressive thickening of the crust or increasing pressure of magma differentiation. Characteristic trace element and isotope systematics (Ba vs. Nb/Y, Th/Yb vs. Ba/La, ²⁰⁶Pb/²⁰⁴Pb vs. Th/Nb, Th/Nb vs. δ¹⁸O, REE) indicate that Eocene magmatism was dominated by fluid-mobile components, whereas Oligocene and Mio-Pliocene magmatism was dominated by a depleted mantle, compositionally modified by subducted sediments.A two-stage magmatic and metallogenic evolution is proposed for the Zangezur–Ordubad region. Eocene normal arc, calc-alkaline to high-K calc-alkaline magmatism was coeval with extensive Eocene magmatism in Iran attributed to Neotethys subduction. Eocene subduction resulted in the emplacement of small tonnage porphyry Cu–Mo deposits. Subsequent Oligocene and Miocene high-K calc-alkaline and shoshonitic to adakitic magmatism, and the second porphyry Cu–Mo deposit stage coincided with Arabia–Eurasia collision to post-collision tectonics. Magmatism and ore formation are linked to asthenospheric upwelling along translithospheric, transpressional regional faults between the Gondwana-derived South Armenian block and the Eurasian margin, resulting in decompression melting of lithospheric mantle, metasomatised by sediment components added to the mantle during the previous Eocene subduction event.     

Early Cretaceous low-Mg adakitic granites from the Dabie orogen,eastern China: Petrogenesis and implications for destruction of the over-thickened lower continental crust

It is generally accepted that the low-Mg adakitic rocks were derived from the partial melting of metabasalts/eclogites. In this study, we demonstrate that the early Cretaceous low-Mg adakitic granites in the North Dabie Complex (NDC) were generated by the partial melting of the NDC orthogneisses. Here we present in-situ U–Pb and Lu–Hf isotopes in zircon with whole-rock geochemical and Sr–Nd isotopic compositions were carried out for the Tiantangzhai porphyritic monzogranites from the Dabie orogen, eastern China. The monzogranites are characterized by high Sr (576–988 ppm), low Y (7.3–19.0 ppm), and depletion in HREE (Yb: 0.50–1.78 ppm) (thus resulting in high Sr/Y (34.3–135.2) and (La/Yb)_N (17.0–105.2) ratios) without a negative Eu anomaly. They also exhibit high SiO₂ (66.5–73.5 wt.%) and K₂O (2.7–4.7 wt.%), and low MgO (0.4–1.6 wt.%) or Mg^# (28.2–45.3, mostly < 40) values. Whole-rock geochemical compositions suggest that the monzogranites represent low-Mg adakitic rock with high-Si and rich-K features equilibrated with residues rich in garnet. Sr–Nd isotopic compositions (ε_Nd (t) = ? 16.2 to ? 20.3, (⁸⁷Sr/⁸⁶Sr)_i = 0.707798–0.708804, t_DM2(Nd) = 2.3–2.6 Ga) of the monzogranites are distinct from that of the eclogites and amphibolites in the Dabie orogen, but similar to that of the Neoproterozoic (700–800 Ma) gneisses in the NDC. U–Pb dating of zircons gives a consistent age of 130.0 ± 3.4 Ma with discordia upper intercept age of 716 ± 34 Ma for inherited cores identified by CL imaging. Correspondingly, in-situ Lu–Hf analyses of early Cretaceous young age-spots from zircons yield initial ¹⁷⁶Hf/¹⁷⁷Hf ratios from 0.281898 to 0.282361, εHf(t) values from ? 28.1 to ? 17.6 and two-stage “crust” Hf model ages (t_DM2) from 2293 ± 89 to 2949 ± 108 Ma, which are generally in agreement with values of 0.281891 to 0.282218, ? 28.2 to ? 11.7 and 1927 ± 87 to 2963 ± 92 Ma for the pre-Mesozoic inherited cores, respectively. As for individual core-rim pairs in zircon, Th/U ratios increase from the inherited cores to the young growth rims possibly due to variable degrees of partial melting, whereas ¹⁷⁶Lu/¹⁷⁷Hf ratios greatly decrease because of the garnet effect in residues. Thus, we suggest that the early Cretaceous low-Mg adakitic granites were derived from the partial melting of the NDC Neoproterozoic (700–800 Ma) gneisses, and the foundering of the garnet-bearing residues could have caused the destruction of the over-thickened lower continental crust.     

Origin of LateTriassic high-Mg adakitic granitoid rocks from the Dongjiangkou area,Qinling orogen,central China: Implications for subduction of continental crust

The origin of high-Mg adakitic granitoids in collisional orogens can provide important information about the nature of the lower crust and upper mantle during the orogenic process. Late-Triassic high-Mg adakitic granite and its mafic enclaves from the Dongjiangkou area, the Qinling orogenic belt, central China, were derived by partial melting of subducted continental crust and underwent interaction with the overlying mantle wedge peridotite. Adakitic affinity of the different facies of the Dongjiangkou granite body are: high Sr, Ba, high La/Yb and Sr/Y, low Y,Yb, Yb/Lu and Dy/Yb, and no significant Eu anomalies, suggesting amphibole + garnet and plagioclase-free restite in their source region. Evolved Sr-Nd-Pb isotopic compositions [(⁸⁷Sr/⁸⁶Sr)_i = 0.7050 to 0.7055,ε_Nd(t) = –6.6 to –3.3; (²⁰⁶Pb/²⁰⁴Pb)_i = 17.599 to 17.799, (²⁰⁷Pb/²⁰⁴Pb)_i = 15.507 to 15.526, (²⁰⁸Pb/²⁰⁴Pb)_i = 37.775 to 37.795] and high K₂O, Rb, together with a large variation in zircon Hf isotopic composition (ε_Hf(t) = ?9.8 to + 5.0), suggest that the granite was derived from reworking of the ancient lower continental crust. CaO, P₂O₅, K₂O/Na₂O, Cr, Ni, Nb/Ta, Rb/Sr and Y increase, and SiO₂, Sr/Y and Eu/Eu* decrease with increasing MgO, consistent with interaction of primitive adakitic melt and overlying mantle peridotite. Zircons separated from the host granites have U-Pb concordia ages of 214 ± 2 Ma to 222 ± 2 Ma, compatible with exhumation ages of Triassic UHP metamorphic rocks in the Dabie orogenic belt. Mafic microgranular enclaves and mafic dykes associated with the granite have identical zircon U-Pb ages of 220 Ma, and are characterized by lower SiO₂, high TiO₂, Mg# and similar evolved Sr-Nd-Pb isotopic composition. Zircons from mafic microgranular enclaves (MMEs) and mafic dykes also show a large variation in Hf isotopic composition with ε_Hf(t) between ?11.3 and + 11.3. It is inferred that they were formed by partial melting of enriched mantle lithosphere and contaminated by the host adakitic granite magma.In combination with the regional geology, high-Mg# adakitic granitoid rocks in the Dongjiangkou area are considered to have resulted from interaction between subducted Yangtze continental crust and the overlying mantle wedge. Triassic continental collision caused detachment of the Yangtze continental lithosphere subducted beneath the North China Craton, at ca. 220 Ma causing asthenosphere upwelling and exhumation of the continental crust. Triassic clockwise rotation of the Yangtze Craton caused extension in the Dabie area which led to rapid exhumation of the subducted continental lithosphere, while compression in the Qinling area and high-P partial melting (amphibole ± garnet stability field) of the subducted continental crust produced adakitic granitic magma that reacted with peridotite to form Mg-rich hybrid magma.     

Geochemistry,geochronology and Sr–Nd–Pb–Hf isotopic compositions of Middle to Late Jurassic syenite–granodiorites–dacite in South China: Petrogenesis and tectonic implications

In situ zircon U–Pb ages and Hf isotope data, major and trace elements and Sr–Nd–Pb isotopic compositions are reported for coeval syenite–granodiorites–dacite association in South China. The shoshonitic syenites are characterized by high K₂O contents (5.9–6.1 wt.%) and K₂O/Na₂O ratios (1.1–1.2), negative Eu anomalies (Eu/Eu* = 0.65 to 0.77), enrichments of Rb, K, Nb, Ta, Zr and Hf, but depletion of Sr, P and Ti. The adakitic granodiorite and granodiorite porphyry intrusions are characterized by high Al₂O₃ contents (15.0–16.8 wt.%), enrichment in light rare earth elements (LREEs), strongly fractionated LREEs (light rare earth elements) to HREEs (heavy rare earth elements), high Sr (438–629 ppm), Sr/Y (29.2–53.6), and low Y (11.7–16.8 ppm) and HREE contents (e.g., Yb = 1.29–1.64 ppm). The calc-alkaline dacites are characterized by LREE enrichment, absence of negative Eu anomalies, and enrichment of LILEs such as Rb, Ba, Th, U and Pb, and depletion of HFSEs such as Nb, Ta, P and Ti.Geochemical and Sr–Nd–Hf isotopic compositions of the syenites suggest that the shoshonitic magmas were differentiated from parental shoshonitic melts by fractional crystallization of olivine, clinopyroxene and feldspar. The parent magmas may have originated from partial melting of the lithospheric mantle with small amount contribution from crustal materials. The adakitic granodiorite and granodiorite porphyry have Sr–Nd–Pb isotopic compositions that are comparable to that of the mafic lower crust. They have low Mg# and MgO, Ni and Cr contents, abundant inherited zircons, low ε_Nd(t) and ε_Hf(t) values as well as old whole-rock Nd and zircon Hf model ages. These granodiorites were likely generated by partial melting of Triassic underplated mafic lower crust. The Hf isotopic compositions of the dacites are relatively more depleted than the Cathaysia enriched mantle, suggesting those magmas were derived from the partial melting of subduction-modified mantle sources. The coeval shoshonitic, high-K calc-alkaline and calc-alkaline rocks in Middle to Late Jurassic appear to be associated with an Andean-type subduction. This subduction could have resulted in the upwelling of the asthenosphere beneath the Cathaysia Block, which induced partial melting of the mantle as well as the mafic lower crust, and formed an arc regime in the coastal South China during Middle to Late Jurassic.     

Origin of Miocene Cu-bearing porphyries in the Zhunuo region of the southern Lhasa subterrane: Constraints from geochronology and geochemistry

The Zhunuo Cu-bearing porphyries are located in the westernmost part of the Miocene Gangdese porphyry Cu (Mo–Au) deposit belt. Zircon U–Pb dating of the diorite porphyry, K-feldspar granite porphyry, and monzonitic granite porphyry in Zhunuo yielded crystallization ages of 12.5 ± 0.4 Ma, 12.3 ± 0.3 Ma, and 12.4 ± 0.3 Ma, respectively. The diorite porphyry is characterized by low SiO₂ (58.61–61.14 wt.%) and Th (0.30–0.76 ppm) concentrations, low Th/La (0.05–0.1) ratios, and high Mg^# (> 49) values coupled with low (⁸⁷Sr/⁸⁶Sr)_i (0.703777–0.703783) and high ε_Nd(t) (+ 4.07 to + 4.90) values. They also have adakite-like affinities, such as low Y (10.5–12.0 ppm), and high Sr/Y ratios (61–65). They were probably derived from a thickened juvenile lower continental crust. The K-feldspar granite porphyry probably originated in the middle–upper continental crust because of their high SiO₂ (73.59–74.98 wt.%) and Th (50.1–52.1 ppm) concentrations, high Th/La (1.67–2.10), and low Sr/Y (20.2–20.7) ratios and Mg^# (32–38) values, combined with high (⁸⁷Sr/⁸⁶Sr)_i (0.710921–0.712008), low ε_Nd(t) (− 8.47 to − 9.26) isotopic compositions and old Nd model ages (1.16–1.25 Ga). Their magmas were most likely partial melts of the preserved ancient crust similar to the central Lhasa subterrane. The geochemical characteristics and Sr–Nd isotopic compositions of the monzonitic granite porphyry display trends that lie between those of the diorite porphyry and K-feldspar granite porphyry, and they are therefore likely to be production of hybridization between the above two melts. The ore-bearing diorite porphyry and monzonitic granite porphyry have higher zircon Ce^4 +/Ce^3 + ratios than the ore-barren K-feldspar granite porphyry, indicating a higher oxygen fugacity in the ore-bearing magmas. We suggest that metals were released from the re-melting of arc-related cumulates which formed during lower crustal growth and thickening. This mechanism provides a reasonable explanation for the significant flare-up of mineralization during the Miocene in the Gangdese region. The lower continental crust beneath southern Lhasa subterrane probably was uniformly juvenile but the region to the west of Zhunuo was not mineralized due to input of large ancient crustal materials in the source of these ore-barren adakite-like rocks.     

Geology,geochemistry, and geochronology of the Wangjiazhuang porphyry–breccia Cu(–Mo) deposit in the Zouping volcanic basin,eastern North China Block

The Wangjiazhuang porphyry–breccia Cu(–Mo) deposit is located in the Zouping volcanic basin, western Shandong Province. Seven molybdenite samples yield a Re–Os weighted mean age of 127.8 ± 0.7 Ma (2σ), which is identical within error to the zircon weighted mean ²⁰⁶Pb/²³⁸U age of 128.3 ± 1.3 Ma (2σ) determined for quartz monzonite samples. The host rock is characterized by high concentrations of K₂O (4.26–4.53 wt.%), Na₂O (4.97–5.76 wt.%), LILEs and LREEs, and high Mg# (> 40), and low concentrations of HFSEs and HREEs, with K₂O/Na₂O ratios of 0.76–0.88. The quartz monzonite also has high Sr/Y (69.9–112.5) and (La/Yb)_N (22.0–30.0) ratios, similar to adakitic rocks worldwide. Relatively low initial ⁸⁷Sr/⁸⁶Sr ratios (0.70549–0.70556), high ε_Nd(t) values (2.58–3.06), high radiogenic Pb [(²⁰⁶Pb/²⁰⁴Pb)i = 18.3424–18.4606, (²⁰⁷Pb/²⁰⁴Pb)_i = 15.5692–15.5985, (²⁰⁸Pb/²⁰⁴Pb)_i = 38.1714–38.2734] and high zircon ε_Hf(t) values (− 2.1 to + 4.3) indicate that the magma was likely derived from the partial melting of subducted oceanic crust which then reacted with the peridotitic mantle wedge. Both the breccia and porphyry ores have a narrow range of δ³⁴S (− 4.8 to + 2.1‰) and Pb isotopic compositions (²⁰⁶Pb/²⁰⁴Pb = 18.295–18.402, ²⁰⁷Pb/²⁰⁴Pb = 15.551–15.573, and ²⁰⁸Pb/²⁰⁴Pb = 38.215–38.331), suggesting that the ore metals were extracted primarily from the quartz monzonite or similar source. Subduction of the Paleo-Pacific slab during the Early Cretaceous resulted in the formation of the Wangjiazhuang quartz monzonite and associated Cu(–Mo) deposit in western Shandong Province.