scholarly journals Zircon U–Pb Ages and Geochemistry of Granitoid in the Yuejinshan Copper–Gold Deposit, NE China: Constraints on Petrogenesis and Metallogenesis

Minerals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1206
Author(s):  
Qingshuang Wang ◽  
Yanlan Wei ◽  
Yanchen Yang ◽  
Hu Peng

Yuejinshan copper–gold orebodies form a hydrothermal deposit located southwest of the Wandashan massif in the western Pacific oceanic tectonic regime. The orebodies are veins and lenses in granite porphyry and skarn or contact zones between these rocks. Early Cretaceous Yuejinshan magmatism provides critical evidence for regional mineralization and tectonic history. In this work, whole-rock major and trace elements and zircon U–Pb data for Yuejinshan granitic intrusions were studied to investigate the geochronological framework, petrogenesis, tectonic implications, and metallogenesis. Granodiorites are calc-alkaline and have geochemical characteristics that indicate affinities with subduction-related crust–mantle magmas derived from partial melting of a mantle wedge and subducted sediments metasomatized by subduction-related fluids. These magmas have experienced fractional crystallization and assimilated crustal materials. Granite porphyries, monzogranites, and quartz diorites are peraluminous, geochemically similar to remelted granites, and derived from partial melting of the crust. Zircon U–Pb LA-ICP-MS data and previous ages indicate that the granitoids were emplaced in the Early Cretaceous. We propose that mineralization mainly occurred at 130 Ma, while magmatism during 116–109 Ma triggered the enrichment of copper and gold in this deposit. Magmatism of different geological ages overlapped spatially and formed the Yuejinshan copper–gold deposit in an active continental margin setting related to the subduction of the Paleo-Pacific Plate.

2021 ◽  
pp. jgs2020-152
Author(s):  
Fei Yang ◽  
Yinglei Li ◽  
Guang Wu ◽  
Huichuan Liu ◽  
Gongzheng Chen ◽  
...  

The Erguna Massif is located in the southwestern portion of the Great Xing'an Range and is adjacent to the Mongol–Okhotsk suture zone. It has not to be determined whether the tectonic evolutionary processes of the Erguna Massif belong to the Mongol–Okhotsk tectonic regime during the Middle Permian–Mesozoic. In this study, a suite of rocks comprising Mesozoic S-type monzogranite (LA–ICP–MS U–Pb zircon age of 248 ± 1.2 Ma), highly fractionated I-type rhyolite (204 ± 1.1 Ma), gabbro (196 ± 1.9 Ma), A2-type volcanic rocks (190 ± 0.9 Ma), A1-type trachydacite (167 ± 0.8 Ma), and Early Cretaceous A1-type alkaline rhyolite are newly identified and geochemically studied. The rhyolite, gabbro, trachydacite, and alkaline rhyolite whole-rock Sr–Nd isotope analyses got the values of initial 87Sr/86Sr ratios ranging from 0.7044 to 0.7058 and εNd(t) values of −0.68–+2.73. These samples show εHf(t) values ranging from +5.3 to +11.2 and TDM2 ranging from 0.48 Ga to 0.90 Ga. The 248 Ma monzogranites were produced by the partial melting of greywackes. The 204 Ma rhyolites were derived from the partial melting of lower mafic crust. The 196 Ma gabbros originated from the partial melting of an enriched mantle metasomatized by subduction-slab released fluids. The 190 Ma volcanic rocks, 167 Ma trachydacite, and Early Cretaceous alkaline rhyolite were mainly formed by the partial melting of the basaltic rocks. They all show enrichment in the large ion lithophile elements (e.g., Rb, Ba, and K) and depletions in the high field strength elements (e.g., Nb, Ta, and Ti), suggesting they formed in an active continental margin setting. The features of these igneous rocks indicate the southward subduction of the Mongol-Okhotsk ocean plate. Based on compiled age data, three phases of middle Mesozoic magmatism were identified in the Erguna Massif at ca. 275–225 Ma, 215–165 Ma, and 150–110 Ma. In addition, three similar magmatic phases were found in the Xing'an Massif. However, a hysteresis about ca. 15–20 Ma exists between the two massifs. These magmatic rocks may record the three stages of the southward subduction of the Mongol–Okhotsk oceanic plate, and two periods of slab rollback occurred during the Middle Permian to Early Cretaceous.Supplementary material:https://doi.org/10.6084/m9.figshare.c.5459285


Lithosphere ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 804-820 ◽  
Author(s):  
Mao-Hui Ge ◽  
Jin-Jiang Zhang ◽  
Long Li ◽  
Kai Liu

Abstract Early Jurassic granitoids are widespread in the Lesser Xing’an–Zhangguangcai Ranges, providing excellent targets to understand the late Paleozoic to early Mesozoic tectonic framework and evolution of Northeast China, especially the Jiamusi block and its related structural belts. In this paper, we present new geochronological, geochemical, and isotopic data from the granitoids in the Lesser Xing’an–Zhangguangcai Ranges to constrain the early Mesozoic tectonic evolution of the Mudanjiang Ocean between the Jiamusi and Songnen blocks. Our results show that the granitic intrusions in the Lesser Xing’an–Zhangguangcai Ranges are mainly composed of syenogranite, monzogranite, granodiorite, and tonalite, which have crystallization ages from 196 to 181 Ma. Their geochemical features indicate that these Jurassic intrusions are all high-K calc-alkaline I-type granites with metaluminous to weakly peraluminous compositions. These granitoids are characterized by enrichments in large ion lithophile elements (e.g., Ba, Th, U) and light rare earth elements and depletions in high field strength elements (e.g., Nb and Ta) and heavy rare earth elements, which are typical for continental arc–type granites. The sources of these granitoids were likely derived from juvenile Mesoproterozoic to Neoproterozoic crustal materials (e.g., metabasaltic rocks). Integrated with data from regional coeval magmatism, metamorphism, metallogeny, and structure, our new data suggest that the granitoids in the Lesser Xing’an–Zhangguangcai Ranges were probably formed in an active continental margin setting, which fits well in our previous model of Early Jurassic westward subduction of the Mudanjiang Ocean between the Jiamusi and Songnen blocks.


Minerals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 266
Author(s):  
Vera A. Trunilina ◽  
Andrei V. Prokopiev

This paper reports the results of a study of magmatic rocks with Sn–W–Au–Ag mineralization from the Kuranakh, Elikchan, and Istekh ore fields in the Northern batholith belt of the north-eastern Verkhoyansk–Kolyma orogenic belt in Eastern Russia. Using petrographic, mineralogical, geochemical, and isotopic methods, we determined the mineral compositions, petrochemistry, and geochemistry of magmatic rocks, the P–T conditions of their generation and crystallization, and their geodynamic affinity. The studied magmatic rocks have common geochemical characteristics that likely reflect the influence of fluids supplied from a long-lived, deep-seated mantle source. The ore fields are characterized by Sn–W–Au–Ag–Pb polygenetic mineralization. The magmatic and metallogenic evolution comprised five stages for the formation of magmatic rocks and ores. During the first stage (Berriasian–Barremian), arc-related magmatic rocks formed in an active continental margin setting and were associated with Au–Ag mineralization. The second, third, and fourth stages (Aptian–Campanian) took place in a crustal extension and rift setting, and were accompanied by Au–Ag and Sn–W mineralization. During the fifth (post-magmatic) stage, Sn–Ag–Sb and Pb–Ag mineralization occurred.


2012 ◽  
Vol 107 (1) ◽  
pp. 43-79 ◽  
Author(s):  
J.-W. Li ◽  
Z.-K. Li ◽  
M.-F. Zhou ◽  
L. Chen ◽  
S.-J. Bi ◽  
...  

2021 ◽  
Vol 116 (6) ◽  
pp. 1253-1265
Author(s):  
Xiao-Ye Jin ◽  
Jian-Xin Zhao ◽  
Yue-Xing Feng ◽  
Albert H. Hofstra ◽  
Xiao-Dong Deng ◽  
...  

Abstract The ages of Carlin-type gold deposits in the Golden Triangle of South China have long been questioned due to the general lack of minerals unequivocally linked to gold deposition that can be precisely dated using conventional radiogenic isotope techniques. Recent advances in U-Pb methods show that calcite can be used to constrain the ages of hydrothermal processes, but few studies have been applied to ore deposits. Herein, we show that this approach can be used to constrain the timing of hydrothermal activity that generated and overprinted the giant Shuiyindong Carlin-type gold deposit in the Golden Triangle. Three stages of calcite (Cal-1, Cal-2, and Cal-3) have been recognized in this deposit based on crosscutting relationships, cathodoluminescence colors, and chemical (U, Pb, and rare earth element [REE]) and isotope (C, O, Sr) compositions. Cal-1 is texturally associated with ore-stage jasperoid and disseminated Au-bearing arsenian pyrite in hydrothermally altered carbonate rocks, which suggests it is synmineralization. Cal-2 fills open spaces and has a distinct orange cathodoluminescence, suggesting that it precipitated during a second fluid pulse. Cal-1 and Cal-2 have similar carbonate rock-buffered chemical and isotopic compositions. Cal-3 occurs in veins that often contain realgar and/or orpiment and are chemically (low U, Pb, and REE) and isotopically (higher δ13C, lower δ18O and Sri values) distinct from Cal-1 and Cal-2, suggesting that it formed from a third fluid. U-Pb isotope analyses, by laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) for U-rich Cal-1 and Cal-2 and by LA-multicollector (MC)-ICP-MS for U-poor Cal-3, yield well-defined age constraints of 204.3 to 202.6, 191.9, and 139.3 to 137.1 Ma for Cal-1, Cal-2, and Cal-3, respectively. These new ages suggest that the Shuiyindong gold deposit formed in the late Triassic and was overprinted by hydrothermal events in the early Jurassic and early Cretaceous. Given the association of Cal-3 with orpiment and realgar, and previous geochronologic studies of several other major gold deposits in the Golden Triangle, we infer that the latest stage of calcite may be associated with an early Cretaceous regional gold metallogenic event. Combined with existing isotopic ages in the region, these new ages lead us to propose that Carlin-type gold deposits in the Golden Triangle formed during two metallogenic episodes in extensional settings, associated with the late Triassic Indochina orogeny and early Cretaceous paleo-Pacific plate subduction. This study shows that the calcite U-Pb method can be used to constrain the timing of Carlin-type gold deposits and successive hydrothermal events.


2020 ◽  
Author(s):  
Jin-Gen Dai ◽  
et al.

Detailed analytical methods in Text S1, major- and trace-element compositions of clinopyroxene, orthopyroxene, and amphibole, whole-rock major and trace elements, Sr-Nd isotopic data, and zircon U-Pb and Lu-Hf data in Tables S1–S7; Figures S1–S5.


2012 ◽  
Vol 55 (2) ◽  
pp. 158-184 ◽  
Author(s):  
Farimah Ayati ◽  
Fuat Yavuz ◽  
Hooshang H. Asadi ◽  
Jeremy P. Richards ◽  
Fred Jourdan

1988 ◽  
Vol 25 (8) ◽  
pp. 1323-1337 ◽  
Author(s):  
James H. Sevigny

Late Proterozoic amphibolites and ultramafic rocks from the southeastern Canadian Cordillera have been analysed for major and trace elements in order to determine the nature and origin of the protoliths. Geologic relations indicate that these rocks were produced during an episode of continental rifting in the Precambrian. Based on rare-earth-element (REE) patterns, immobile-incompatible-element ratios, and characteristic elemental abundances, amphibolites are subdivided into alkaline and tholeiitic metabasalts. Alkaline basalts are recognized by their steep REE patterns, high Zr/Y, high TiO2 and P2O5 abundances, and low Y/Nb and Ti/Zr. Tholeiitic basalts are subdivided into three groups: (I) high-Mg#, high-field-strength-element (HFSE)-depleted, light-REE (LREE)-enriched tholeiites with flat heavy REE (HREE) patterns; (II) LREE-enriched tholeiites depleted in HREE; and (III) low-Mg# tholeiites with flat REE patterns. Ultramafic rocks occur as boudins of partially recrystallized Cr-spinel-bearing harzburgite or therzolite, enriched in LREE (Ce/Sm = 1.7–1.9), HFSE, CaO, Al2O3, and TiO2 relative to depleted mantle.Geochemical data suggest that the basalts were derived from a heterogeneous mantle source that underwent different degrees of partial melting with variable amounts of subsequent crystal fractionation of the melts. High Mg#, high Cr and Ni abundances, low HFSE abundances, and high olivine saturation temperatures suggest that group I tholeiites are primary mantle melts produced by a relatively high degree of partial melting of a LREE-enriched, HFSE-depleted source. Group II and III basalts have undergone moderate olivine and pryoxene and limited plagioclase fractionation. Mass-balance calculations suggest that the ultramafic rocks represent a crustally contaminated primary-mantle-derived melt.Les éléments majeurs et traces des amphibolites et des ultramafites, d'âge protérozoïque tardif, du sud-est de la Cordillère canadienne ont été analysés dans le but de déterminer la nature et l'origine des protolithes. Les relations géologiques indiquent que ces roches se sont formées durant un épisode de rifting continental dans le Précambrien. Les diagrammes des terres rares, les rapports des éléments immobiles et incompatibles et les compositions chimiques caractéristiques ont permis de subdiviser les amphibolites en métabasaltes tholéiitiques et alcalins. Les basaltes alcalins sont reconnus par les courbes abruptes dans les diagrammes des terres rares, les rapports Zr/Y élevés et les fortes teneurs en TiO2 et P2O5 et les rapports Y/Nb et Ti/Zr faibles. Les basaltes tholéiitiques sont subdivisés en trois groupes : (I) avec Mg# élevé, appauvrissement en éléments de force de champ élevée, tholéiites enrichies en terres rares légères avec courbe horizontale des terres rares lourdes; (II) tholéiites enrichies en terres rares légères et appauvries en terres rares lourdes; et (III) tholéiites avec Mg# faible et avec courbe horizontale des variations des terres rares. Les ultramafites se présentent en boudins formés d'harzburgite incluant un spinelle chromifère partiellement recristallisé ou de therzolite qui sont enrichies en terres rares légères (Ce/Sm = 1,7–1,9), en éléments à force de champ élevée, en CaO, Al2O3 et TiO2, comparativement à un manteau appauvri.


Sign in / Sign up

Export Citation Format

Share Document