Sign in to use this feature.

Years

Between: -

Subjects

remove_circle_outline
remove_circle_outline

Journals

Article Types

Countries / Regions

Search Results (23)

Search Parameters:
Keywords = zircon chemistry and isotopes

Order results
Result details
Results per page
Select all
Export citation of selected articles as:
28 pages, 18316 KB  
Article
Chemistry of Zircon and Its Implication on the Petrogenesis of Cretaceous Volcanic Rocks from the Southeastern Coast of Zhejiang Province, South China
by Zhijie Zeng, Zengcai Tang, Uzair Siddique, Yifan Wang, Jian Liu, Bingzhen Fu and Zilong Li
Minerals 2025, 15(11), 1147; https://doi.org/10.3390/min15111147 - 31 Oct 2025
Viewed by 498
Abstract
The Cretaceous marks the peak of magmatic activity in southeastern (SE) China, which is attributed to the subduction of the paleo-Pacific plate beneath the South China Block. This region constitutes a significant igneous belt along the active continental margin of the western Pacific. [...] Read more.
The Cretaceous marks the peak of magmatic activity in southeastern (SE) China, which is attributed to the subduction of the paleo-Pacific plate beneath the South China Block. This region constitutes a significant igneous belt along the active continental margin of the western Pacific. Despite extensive research, the origin and evolution of Cretaceous felsic volcanic rocks are still debated. This study investigates the characteristics of zircon U-Pb-Hf isotopes and trace elements, and whole-rock geochemistry of Cretaceous volcanic rocks from the Wenzhou–Taizhou region in SE Zhejiang, and discusses their spatio-temporal patterns and petrogenesis. The results indicate that rhyolitic volcanic rocks formed during the period ca. 114 Ma and 95 Ma, representing two distinct magmatic episodes spanning the transition from the late Early to early Late Cretaceous. The late Early Cretaceous and early Late Cretaceous volcanic rocks are of a hybrid crust–mantle origin, as evidenced by their distinct Nb/Ta ratios, zircon εHf(t) values, and variable trace element enrichments (Ti, Hf, U, Nb, and Yb). These compositional signatures suggest partial melting of late Paleoproterozoic to early Mesoproterozoic basement materials, with increasing mantle contributions over time. Both volcanic phases exhibit elevated Nb/Yb, Th/Nb, and U/Yb ratios, indicating a subduction-modified source akin to arc magmas. Together with calculated initial melt temperatures (<800 °C for Early Cretaceous, >800 °C for Late Cretaceous) and whole-rock rare-earth elements (REEs) distribution patterns (U-shaped with δEu = 0.37–0.65, seagull-shaped with δEu = 0.19–0.62, respectively), it is suggested that both phases of the volcanic magmas were generated through water-assisted (hydrous) melting, whereas the later phase formed at relatively higher temperatures and with a diminished water contribution via dehydration melting under extensional conditions. The generation of voluminous high-silica magmas in the SE China coastal region is probably linked to the rollback and retreat of the paleo-Pacific plate. Full article
(This article belongs to the Section Mineral Geochemistry and Geochronology)
Show Figures

Figure 1

31 pages, 9920 KB  
Article
Genesis of Early Cretaceous Magmatism in the Western Gangdese Belt, Southern Tibet: Implications for Neo-Tethyan Oceanic Slab Subduction
by Jiqing Lin, Ke Gao, Zizheng Wang, Zhongbiao Xu and Yongping Pan
Minerals 2025, 15(11), 1143; https://doi.org/10.3390/min15111143 - 30 Oct 2025
Viewed by 440
Abstract
Research on the Mesozoic–Cenozoic magmatism and the tectonic framework within the Lhasa Terrane is voluminous. However, the sparse documentation of Early Cretaceous magmatism in this region fuels ongoing debate over the prevailing tectonic regime during this time period (i.e., normal subduction vs. flat [...] Read more.
Research on the Mesozoic–Cenozoic magmatism and the tectonic framework within the Lhasa Terrane is voluminous. However, the sparse documentation of Early Cretaceous magmatism in this region fuels ongoing debate over the prevailing tectonic regime during this time period (i.e., normal subduction vs. flat subduction). The present study investigates the Luerma pyroxenite and Boyun granitoid in the Western Lhasa Terrane through zircon U-Pb dating, whole-rock geochemistry, mineral chemistry, and Sr-Nd-Hf isotopes. The findings date the formation of Luerma pyroxenite at 115 Ma and Boyun granites at 113 Ma to the Early Cretaceous period (115–113 Ma). SiO2 content of pyroxenite is relatively low (34.27–44.16 wt.%), characterized by an enrichment in large ion lithophile elements (LILEs), light rare earth elements (LREEs), and a depletion in heavy field strength elements (HSFEs), indicative of a metasomatic origin. The εNd (t) and εHf (t) values of the Early Cretaceous ultrabasic rocks range from +2.1 to +2.7 and −0.8 to +10.1, respectively, suggesting their derivation from an enriched mantle source with asthenospheric material incorporation. The Early Cretaceous granodiorites and their mafic enclaves belong to the high-K calc-alkaline series, and show enrichment in LILEs (e.g., Rb, Ba, U, and Th) and depletion in HFSEs (e.g., Nb, Ta, Ti, and Zr). The acidic rocks and their developed mafic enclaves exhibit the geochemical characteristics of trace elements found in island arc magmas. Their εNd (t) values are (−6.0–−5.0), while their εHf (t) values are (−11.7–−1.8); the MMEs εHf (t) values are (−4.1–+0.9). In summary, the Early Cretaceous pyroxenite in the Gangdese Belt originated from a combination of asthenospheric and enriched lithospheric mantle melts, while the granitoids were generated by partial melting of the mantle wedge, a process driven by metasomatism resulting from the slab-derived fluids. At the same time, heat from upwelling mantle-derived melts induced the partial melting of lower crustal materials, leading to the formation of acidic magmas through varying degrees of mixing with basic magmas. This study suggests that Early Cretaceous magmatic activity occurred within a northward subduction setting, characterized by the rotation and fragmentation of the Neo-Tethys oceanic crust. Full article
(This article belongs to the Section Mineral Geochemistry and Geochronology)
Show Figures

Figure 1

38 pages, 13807 KB  
Article
A Sediment Provenance Study of Middle Jurassic to Cretaceous Strata in the Eastern Sverdrup Basin: Implications for the Exhumation of the Northeastern Canadian-Greenlandic Shield
by Michael A. Pointon, Helen Smyth, Jenny E. Omma, Andrew C. Morton, Simon Schneider, Stephen J. Rippington, Berta Lopez-Mir, Quentin G. Crowley, Dirk Frei and Michael J. Flowerdew
Geosciences 2025, 15(8), 313; https://doi.org/10.3390/geosciences15080313 - 12 Aug 2025
Viewed by 2078
Abstract
The Sverdrup Basin, Arctic Canada, is ideally situated to contain an archive of tectono-magmatic and climatic events that occurred within the wider Arctic region, including the exhumation of the adjacent (northeastern) part of the Canadian-Greenlandic Shield. To test this, a multi-analytical provenance study [...] Read more.
The Sverdrup Basin, Arctic Canada, is ideally situated to contain an archive of tectono-magmatic and climatic events that occurred within the wider Arctic region, including the exhumation of the adjacent (northeastern) part of the Canadian-Greenlandic Shield. To test this, a multi-analytical provenance study of Middle Jurassic to Cretaceous sandstones from the eastern Sverdrup Basin was undertaken. Most of the samples analysed were recycled from sedimentary rocks of the Franklinian Basin, with possible additional contributions from the Mesoproterozoic Bylot basins and metasedimentary shield rocks. The amount of high-grade metamorphic detritus in samples from central Ellesmere Island increased from Middle Jurassic times. This is interpreted to reflect exhumation of the area to the southeast/east of the Sverdrup Basin. Exhumation may have its origins in Middle Jurassic extension and uplift along the northwest Sverdrup Basin margin. Rift-flank uplift along the Canadian–West Greenland conjugate margin and lithospheric doming linked with the proximity of the Iceland hotspot and/or the emplacement of the Cretaceous High Arctic Large Igneous Province may have contributed to exhumation subsequently. The southeast-to-northwest thickening of Jurassic to Early Cretaceous strata across the Sverdrup Basin may be a distal effect of exhumation rather than rifting in the Sverdrup or Amerasia basins. Full article
Show Figures

Figure 1

30 pages, 15713 KB  
Article
Magma Mixing Origin for the Menyuan Granodioritic Pluton in the North Qilian Orogenic Belt, China
by Shugang Xia, Yu Qi, Shengyao Yu, Xiaocong Jiang, Xiangyu Gao, Yue Wang, Chuanzhi Li, Qian Wang, Lintao Wang and Yinbiao Peng
Minerals 2025, 15(4), 391; https://doi.org/10.3390/min15040391 - 8 Apr 2025
Cited by 1 | Viewed by 1040
Abstract
Magma mixing or mingling is not just a geological phenomenon that widely occurs in granitoid magmatism, but a complex dynamic process that influences the formation of mafic microgranular enclaves (MMEs) and the diversity of granitic rocks. Herein, we carried out a comprehensive study [...] Read more.
Magma mixing or mingling is not just a geological phenomenon that widely occurs in granitoid magmatism, but a complex dynamic process that influences the formation of mafic microgranular enclaves (MMEs) and the diversity of granitic rocks. Herein, we carried out a comprehensive study that encompassed the petrology, mineral chemistry, zircon U-Pb ages, Lu-Hf isotopes, whole-rock elements, and Sr-Nd isotope compositions of the Menyuan Granodioritic Pluton in the northern margin of the Qilian Block, to elucidate the petrogenesis and physical and chemical processes occurring during magma mixing. The Menyuan Granodioritic Pluton is mainly composed of granodiorites accompanied by numerous mafic microgranular enclaves (MMEs) and is intruded by minor gabbro dikes. LA-ICP-MS zircon U-Pb dating reveals that these rocks possess a similar crystallization age of ca. 456 Ma. The Menyuan host granodiorites, characterized as metaluminous to weakly peraluminous, belong to subduction-related I-type calc-alkaline granites. The MMEs and gabbroic dikes have relatively low SiO2 contents and high Mg# values, probably reflecting a mantle-derived origin. They are enriched in large ion lithophile elements (LILEs) and light, rare earth elements (LREEs) but are depleted in high field strength elements (HFSEs), indicating continental arc-like geochemical affinities. The host granodiorites yield relatively enriched whole-rock Sr-Nd and zircon Hf isotopic compositions (87Sr/86Sri = 0.7072–0.7158; εNd(t) = −9.21 to −4.23; εHf(t) = −8.8 to −1.2), implying a derivation from the anatexis of the ancient mafic lower continental crust beneath the Qilian Block. The MMEs have similar initial Sr isotopes but distinct whole-rock Nd and zircon Hf isotopic compositions compared with the host granodiorites (87Sr/86Sri = 0.7078–0.7089; εNd(t) = −3.88 to −1.68; εHf(t) = −0.1 to +4.1). Field observation, microtextural and mineral chemical evidence, geochemical characteristics, and whole-rock Nd and zircon Hf isotopic differences between the host granodiorites and MMEs suggest insufficient magma mixing of lithospheric mantle mafic magma and lower continental crust felsic melt. In combination with evidence from regional geology, we propose that the anatexis of the ancient mafic lower continental crust and subsequent magma mixing formed in an active continental arc setting, which was triggered by the subducted slab rollback and mantle upwelling during the southward subduction of the Qilian Proto-Tethys Ocean during the Middle-Late Ordovician. Full article
(This article belongs to the Special Issue Tectonic Evolution of the Tethys Ocean in the Qinghai–Tibet Plateau)
Show Figures

Figure 1

24 pages, 19611 KB  
Article
Caledonian Sn Mineralization in the Yuechengling Granitic Batholith, South China: Geochronology, Geochemistry, Zircon Hf Isotopes, and Tourmaline Chemistry and B Isotopes of the Lijia Sn Deposit and Its Hosting Granites
by Yuhang Liu, Congcong Wang, Meng Feng, Yan Cui, Guicong Fang, Zuohai Feng, Wei Fu, Chuan Zhao and Chunzeng Wang
Minerals 2024, 14(12), 1243; https://doi.org/10.3390/min14121243 - 6 Dec 2024
Cited by 2 | Viewed by 1468
Abstract
The Lijia Sn deposit, located in northeastern Guangxi Zhuang Autonomous Region of south China, occurs on the eastern margin of the Yuechengling granite batholith. The Sn deposit contains quartz vein type and greisen type ores and is spatially associated with the medium-coarse-grained biotite [...] Read more.
The Lijia Sn deposit, located in northeastern Guangxi Zhuang Autonomous Region of south China, occurs on the eastern margin of the Yuechengling granite batholith. The Sn deposit contains quartz vein type and greisen type ores and is spatially associated with the medium-coarse-grained biotite granite and the fine-grained tourmaline-bearing biotite granite. LA-ICP-MS zircon U-Pb dating gave an emplacement age of 431.7 ± 2.5 Ma for the medium-coarse-grained biotite granite and of 430.2 ± 2.4 Ma for the fine-grained tourmaline-bearing biotite granite. LA-ICP-MS cassiterite U-Pb dating yielded Tera-Wasserburg lower intercept ages of 429.1 ± 3.4 Ma and 425.7 ± 3.3 Ma for the quartz vein type and greisen type ores, respectively. The ages demonstrate near coeval Caledonian granitic emplacement and Sn mineralization events that have been considered uncommon in south China. Both granites might be derived from partial melting of the Paleoproterozoic basement, as evidenced from zircon ɛHf(t) values of −3.13 to −10.31 and TDM2 from 1627 Ma to 2134 Ma. Three different types of tourmalines have been identified, including (1) tourmaline in quartz–tourmaline nodules in the fine-grained tourmaline-bearing biotite granite (Tur 1), (2) tourmaline in quartz veins (Tur 2a), and (3) tourmaline in greisen (Tur 2b). Most of the tourmalines belong to the alkali group and the schorl-dravite solid-solution series. The hydrothermal tourmalines of Tur 2a and Tur2b showed similar δ11B values to those of the Tur 1 tourmalines in the fine-grained tourmaline-bearing biotite granite, suggesting ore-forming materials derived from granitic magmas. The hydrothermal tourmalines of Tur 2b had slightly lower δ11B values than Tur 1 and Tur 2a tourmalines as a result of progressive 11B depletion during early tourmaline crystallization. Full article
(This article belongs to the Section Mineral Geochemistry and Geochronology)
Show Figures

Graphical abstract

20 pages, 21100 KB  
Article
Petrogenesis and Metallogenic Significance of the Demingding Mo-Cu Porphyry Deposit in the Gangdese Belt, Xizang: Insights from U-Pb and Re-Os Geochronology and Geochemistry
by Sudong Shi, Shuyuan Chen, Sangjiancuo Luo, Huan Ren and Xiaojia Jiang
Minerals 2024, 14(12), 1232; https://doi.org/10.3390/min14121232 - 3 Dec 2024
Cited by 1 | Viewed by 1468
Abstract
The 1500 km-long Gangdese magmatic belt is a crucial region for copper polymetallic mineralization, offering valuable insights into collisional porphyry copper systems. This study focuses on the Demingding deposit, a newly identified occurrence of molybdenum–copper (Mo-Cu) mineralization within the eastern segment of the [...] Read more.
The 1500 km-long Gangdese magmatic belt is a crucial region for copper polymetallic mineralization, offering valuable insights into collisional porphyry copper systems. This study focuses on the Demingding deposit, a newly identified occurrence of molybdenum–copper (Mo-Cu) mineralization within the eastern segment of the belt. While the mineralization age, magmatic characteristics, and tectonic context are still under investigation, we examine the deposit’s petrology, zircon U-Pb geochronology, whole-rock chemistry, and Re-Os isotopic data. The Demingding deposit exhibits a typical alteration zoning, transitioning from an inner potassic zone to an outer propylitic zone, which is significantly overprinted by phyllic alteration closely associated with Mo and Cu mineralization. Zircon U-Pb dating of the ore-forming monzogranite porphyries reveals crystallization ages ranging from 21 to 19 Ma, which is indistinguishable within error from the mean Re-Os age of 21.3 ± 0.4 Ma for Mo veins and veinlets hosted by these porphyries. This alignment suggests a late Miocene magmatic event characterized by Mo-dominated mineralization, coinciding with the continuous thickening of the continental crust during the collision of the Indian and Asian continents. The ore-forming porphyries range in composition from granodiorite to monzogranite and are classified as high-K calc-alkaline with adakite-like features, primarily resulting from the partial melting of subduction-modified thickened mafic lower crust. Notably, the ore-forming porphyries exhibit higher fO2 and H2O levels than barren porphyries in this area during crustal thickening, highlighting the significant contributions of hydrous and oxidized fluids from their source to the Mo-Cu mineralization process. Regional data indicate that the Gangdese porphyry metallogenic belt experienced concentrated Cu-Mo mineralization between 17 and 13 Ma. The formation of Mo-dominated deposits such as Demingding and Tangbula in the eastern segment of the belt, with slightly older ages around 20 Ma, underscores the presence of a significant porphyry Mo metallogenic event during this critical post-collision mineralization period. Full article
Show Figures

Graphical abstract

21 pages, 20991 KB  
Article
Petrogenesis of Diorite-Porphyrite in the Southern Xintai Area of the Mid-Western Shandong Peninsula, North China Craton: Insights from Geochronology, Mineralogy, Geochemistry, and Sr-Nd-Hf Isotopes
by Lijie Jin, Jilin Wang, Pinrui Qin, Chunjia Li, Shuang Xu, Zhixin Han, Wei Wang, Wei Liu, Zisheng Wang, Jilei Gao and Fangfang Li
Minerals 2024, 14(12), 1220; https://doi.org/10.3390/min14121220 - 29 Nov 2024
Viewed by 1242
Abstract
The Early Cretaceous intermediate intrusive rocks have important significance in understanding the crust–mantle interaction, iron mineralization, and tectonic evolution in the western Shandong Peninsula. In this study, we present new zircon U–Pb ages, and Hf isotope, whole-rock geochemistry, Sr–Nd isotopes, and the mineral [...] Read more.
The Early Cretaceous intermediate intrusive rocks have important significance in understanding the crust–mantle interaction, iron mineralization, and tectonic evolution in the western Shandong Peninsula. In this study, we present new zircon U–Pb ages, and Hf isotope, whole-rock geochemistry, Sr–Nd isotopes, and the mineral chemistry of the diorite-porphyrite in the southern Xintai area, mid-western Shandong Peninsula. The diorite-porphyrite formed at ca. 125 Ma. They have intermediate SiO2 (59.57–62.29 wt.%) and MgO (2.78–3.58 wt.%) contents, high Mg# values (53–56), high Sr (589–939 ppm) and low Y (9.2–10.8 ppm) contents, and high Sr/Y ratios (54–94), showing adakitic affinity. The diorite-porphyrite exhibits lower zircon εHf(t) values (−30.1 to 7.5) and whole-rock εNd(t) values (−3.5 to −6.0), with (87Sr/86Sr)i ratios of 0.70514–0.70567. We suggest that the diorite-porphyrite was derived from the partial melting of the local delamination of lower continental crust and then by the interaction with the enriched lithospheric mantle. The genesis of diorite-porphyrite may be related to the rollback process of the Paleo-Pacific slab in the Early Cretaceous. This geodynamic process induced the melting of the enriched lithospheric mantle, subducted oceanic crust, and local delamination of lower continental crust, which produced different types of adakitic magmatism in the western Shandong Peninsula. Full article
Show Figures

Figure 1

35 pages, 9267 KB  
Article
Petrogenesis of Late Stenian Syn-Orogenic A-Type Granites in the Chhotanagpur Gneissic Complex and Eastern Indian Shield
by Bapi Goswami, Ankita Basak, Yoann Gréau and Chittaranjan Bhattacharyya
Minerals 2024, 14(11), 1153; https://doi.org/10.3390/min14111153 - 14 Nov 2024
Cited by 1 | Viewed by 2008
Abstract
We report the petrogenesis of arfvedsonite granites from the Dimra Pahar pluton in the Chhotanagpur Gneissic Complex based on petrology, whole-rock chemistry, mineral chemistry, and La-ICP-MS zircon U-Pb ages and Hf-Lu isotopic analyses. These granites are dominantly peralkaline, occasionally peraluminous, and demonstrate features [...] Read more.
We report the petrogenesis of arfvedsonite granites from the Dimra Pahar pluton in the Chhotanagpur Gneissic Complex based on petrology, whole-rock chemistry, mineral chemistry, and La-ICP-MS zircon U-Pb ages and Hf-Lu isotopic analyses. These granites are dominantly peralkaline, occasionally peraluminous, and demonstrate features of A1-type granites. The magma was emplaced at a shallow depth and had a high liquidus temperature, fO2 (>NNO), and water saturation. The zircons exhibit three distinct U-Pb isotopic ages. The oldest (1324 ± 6 Ma), large-sized inherited zircons (εHf(t) = +1.65 to +7.64), show complex zoning and signs of partial resorption. The euhedral, prismatic-bipyramidal zircons displaying oscillatory zoning (εHf(t) = −3.43 to +1.43) reveal a crystallization age of 1046 ± 7 Ma. Their thin periphery (εHf(t) = −3.23 to +0.27) grew during retrograde metamorphism (995 ± 6 Ma). The whole-rock geochemistry and the Hf-isotope values imply that the parental magma of these granites resulted from the anatexis of metasomatized lithospheric mantle sources. These granites intruded in a syn-orogenic (syn-collisional exhumation) stage of the orogeny. Full article
(This article belongs to the Special Issue Geochronology and Geochemistry of Alkaline Rocks)
Show Figures

Figure 1

23 pages, 5679 KB  
Article
Mineralogical and Geochemical Response to Fluid Infiltration into Cambrian Orthopyroxene-Bearing Granitoids and Gneisses, Dronning Maud Land, Antarctica
by Ane K. Engvik, Fernando Corfu, Ilka C. Kleinhanns, Heinrich Taubald and Synnøve Elvevold
Minerals 2024, 14(8), 772; https://doi.org/10.3390/min14080772 - 29 Jul 2024
Cited by 1 | Viewed by 1353
Abstract
Fluid infiltration into Proterozoic and Early Palaeozoic dry, orthopyroxene-bearing granitoids and gneisses in Dronning Maud Land, Antarctica, has caused changes to rock appearance, mineralogy, and rock chemistry. The main mineralogical changes are the replacement of orthopyroxene by hornblende and biotite, ilmenite by titanite, [...] Read more.
Fluid infiltration into Proterozoic and Early Palaeozoic dry, orthopyroxene-bearing granitoids and gneisses in Dronning Maud Land, Antarctica, has caused changes to rock appearance, mineralogy, and rock chemistry. The main mineralogical changes are the replacement of orthopyroxene by hornblende and biotite, ilmenite by titanite, and various changes in feldspar structure and composition. Geochemically, these processes resulted in general gains of Si, mostly of Al, and marginally of K and Na but losses of Fe, Mg, Ti, Ca, and P. The isotopic oxygen composition (δ18OSMOW = 6.0‰–9.9‰) is in accordance with that of the magmatic precursor, both for the host rock and infiltrating fluid. U-Pb isotopes in zircon of the altered and unaltered syenite to quartz-monzonite indicate a primary crystallization age of 520.2 ± 1.0 Ma, while titanite defines alteration at 485.5 ± 1.4 Ma. Two sets of gneiss samples yield a Rb-Sr age of 517 ± 6 Ma and a Sm-Nd age of 536 ± 23 Ma. The initial Sr and Nd isotopic ratios suggest derivation of the gneisses from a relatively juvenile source but with a very strong metasomatic effect that introduced radiogenic Sr into the system. The granitoid data indicate instead a derivation from Mid-Proterozoic crust, probably with additions of mantle components. Full article
Show Figures

Figure 1

20 pages, 23085 KB  
Article
Origin of the Kunduleng Granite and Its Associated Uranium Anomaly in the Southern Great Xing’an Range, NE China
by Jiaxing Sun, Deyou Sun, Jun Gou, Dongguang Yang, Changdong Wang, Li Tian and Duo Zhang
Minerals 2024, 14(7), 666; https://doi.org/10.3390/min14070666 - 27 Jun 2024
Viewed by 1537
Abstract
The Kunduleng granite hosts one of several significant uranium anomalies within the southern Great Xing’an Range, NE China. Whole-rock geochemistry and mineral chemistry data, along with the zircon U-Pb-Hf isotope have been used to constrain the petrogenesis of this granitic intrusion and the [...] Read more.
The Kunduleng granite hosts one of several significant uranium anomalies within the southern Great Xing’an Range, NE China. Whole-rock geochemistry and mineral chemistry data, along with the zircon U-Pb-Hf isotope have been used to constrain the petrogenesis of this granitic intrusion and the origin of the uranium anomaly. Microscopically, quartz, alkali-feldspar, and plagioclase are the essential mineral constituents of the granite, with minor biotite, while monazite, apatite, xenotime, and zircon are accessory minerals. Geochemically, the silica- and alkali-rich granites show a highly fractionated character with “seagull-shaped” REE patterns and significant negative anomalies of Ba and Sr, along with low Zr/Hf and Nb/Ta ratios. The granite has positive zircon εHf(t) values ranging from +12.7 to +14.5 and crustal model ages (TDM2) of 259–376 Ma, indicating a Paleozoic juvenile crustal source. Uraninite and brannerite are the main radioactive minerals responsible for the uranium anomaly within the Kunduleng granite. Uraninite presents well-developed cubic crystals and occurs as tiny inclusions in quartz and K-feldspar with magmatic characteristics (e.g., elevated ThO2, Y2O3, and REE2O3 contents and low CaO, FeO, and SiO2 concentrations). The calculated U-Th-Pb chemical ages (135.4 Ma) are contemporaneous with the U-Pb zircon age (135.4–135.6 Ma) of the granite, indicating a magmatic genesis for uraninite. The granites are highly differentiated, and extreme magmatic fractionation might be the main mechanism for the initial uranium enrichment. Brannerite is relatively less abundant and typically forms crusts on ilmenite and rutile or it cements them, representing the local redistribution and accumulation of uranium. Full article
(This article belongs to the Special Issue Mineralization in Subduction Zone)
Show Figures

Figure 1

19 pages, 16233 KB  
Article
Late Cretaceous-Paleocene Arc and Back-Arc System in the Neotethys Ocean, Zagros Suture Zone
by Yousif Mohammad, Kurda Abdulla and Hossein Azizi
Minerals 2023, 13(11), 1367; https://doi.org/10.3390/min13111367 - 26 Oct 2023
Cited by 8 | Viewed by 2643
Abstract
The Bulfat Igneous Complex comprises the Bulfat and Walash groups and is situated in the Zagros Suture Zone, in the junction of Arabian and Eurasian plates. Zircon U-Pb data indicat an age of 63.7 ± 1.5 Ma for the trondhjemite rocks within the [...] Read more.
The Bulfat Igneous Complex comprises the Bulfat and Walash groups and is situated in the Zagros Suture Zone, in the junction of Arabian and Eurasian plates. Zircon U-Pb data indicat an age of 63.7 ± 1.5 Ma for the trondhjemite rocks within the Bulfat group. Walash group is primarily composed of basalt to andesite rocks, interbedded with sedimentary rocks. Zircon U-Pb dating yields an age of 69.7 ± 2.7 Ma for the Walash group. Whole rocks chemistry shows that the Bulfat rocks have affinity to MORB and calc alkaline series but Walsh are mainly plot in the calc alkaline field. Whole rocks Sr-Nd isotope ratios show that the 143Nd/144Nd (i) changes from 0.51243 to 0.52189 and 87Sr/86Sr(i) ratios vary from 0.70345 to 0.7086. The calculated εNd(t) values, based on the CHUR, yield predominantly high positive values ranging from +6 to +8 for most samples. However, a few samples exhibit lower values (+2 to +3). Our data suggest that the interaction between lithospheric (depleted mantle, MORB-Like) and asthenospheric mantle (OIB-like) melts significantly controlled the magmatic evolution of the Bulfat group. The strong positive εNd(t) values (ranging from +6 to +8) align more consistently with a highly depleted lithospheric mantle source for the Walsh group. Therefore, the gradual transition from an arc signature at 70 Ma to a MORB signature around 63 Ma, occurred over a relatively short period of about 10 million years, and indicates the presence of an arc and back-arc system in the Neotethys ocean before the collision of the Arabian and Iran plates during the Cenozoic. Full article
(This article belongs to the Special Issue Petrogenesis, Magmatism and Geodynamics of Orogenic Belts)
Show Figures

Figure 1

21 pages, 11697 KB  
Article
Origin of Quartz Diorite and Mafic Enclaves in the Delong Gold-Copper Deposit and Evaluation of the Gold-Copper Mineralization Potential
by Jiajie Chen, Lebing Fu, Chengbiao Leng, Xu Zhao, Jian Ma, Hongze Gao and Yu Xia
Minerals 2023, 13(9), 1202; https://doi.org/10.3390/min13091202 - 13 Sep 2023
Cited by 1 | Viewed by 2118
Abstract
The Triassic Paleo-Tethyan magmatic belt in the East Kunlun Orogen (EKO) hosts a small number of porphyry-skarn deposits. The controls of these deposits, especially those in the eastern EKO, are poorly understood. In this contribution, we report new petrological, zircon U-Th-Pb-Hf isotopic, whole-rock [...] Read more.
The Triassic Paleo-Tethyan magmatic belt in the East Kunlun Orogen (EKO) hosts a small number of porphyry-skarn deposits. The controls of these deposits, especially those in the eastern EKO, are poorly understood. In this contribution, we report new petrological, zircon U-Th-Pb-Hf isotopic, whole-rock elemental with Sr-Nd isotopic, and mineral chemistry data of the Delong quartz diorite and mafic enclaves to constrain their petrogenesis and metal fertility. The quartz diorite and mafic enclaves are emplaced in the Late Triassic (ca. 234 Ma). They are medium-K, metaluminous, enriched in large-ion lithophile elements (e.g., Rb, Ba, Th) and light rare earth elements (e.g., La, Ce, Nd), and relatively depleted in high field strength elements (e.g., Nb, Ta, Ti, P) and heavy rare earth elements (e.g., Gd, Er, Tm, Yb). The quartz diorite show similar (87Sr/86Sr)i (0.712584~0.713172) and more depleted εNd(t) (−6.4~−5.7) and εHf(t) (−2.3~+2.6) to those of mafic enclaves ((87Sr/86Sr)i = 0.712463~0.713093; εNd(t) = −6.4~−6.0; εHf(t) = −9.4~−4.8). Geochemical compositions of zircon, amphibole, and biotite yield high water content (5.3 wt.%~6.9 wt.% and 6.1 wt.%~7.3 wt.% based on amphibole, respectively) and high redox state for both the quartz diorite and mafic enclaves. These data, together with petrography, indicate the Delong intrusion was formed by mingling of magmas from enriched mantle and lower continental crust with juvenile materials. The oxidized and water-rich features of these magmas denote they have potential for porphyry Cu (±Au ± Mo) deposits, as do some Triassic magmatic rocks in the eastern EKO that show similar geochemical and petrographic characteristics with the Delong intrusion. Full article
(This article belongs to the Section Mineral Deposits)
Show Figures

Figure 1

20 pages, 4025 KB  
Article
The Genetic Link between Iron-Oxide–Apatite and Porphyry Cu–Au Mineralization: Insight from the Biotite–Pyroxene–Zircon Study of the Nihe Fe Deposit and the Shaxi Cu–Au Deposit in the Lower Yangtze Valley, SE China
by Yi Li, Ke-Zhang Qin, Guo-Xue Song, Yu Fan, Fang-Yue Wang and Le Wang
Minerals 2023, 13(3), 451; https://doi.org/10.3390/min13030451 - 22 Mar 2023
Cited by 26 | Viewed by 2599
Abstract
Different ore deposit types may evolve from a common magmatic-hydrothermal system. Establishing a genetic link between different deposit types in an ore cluster can not only deepen the understanding of the magmatic-hydrothermal mineralization process but can also guide exploration. Both the Nihe iron-oxide–apatite [...] Read more.
Different ore deposit types may evolve from a common magmatic-hydrothermal system. Establishing a genetic link between different deposit types in an ore cluster can not only deepen the understanding of the magmatic-hydrothermal mineralization process but can also guide exploration. Both the Nihe iron-oxide–apatite (IOA) deposit and the Shaxi porphyry Cu–Au deposit in the Lower Yangtze Valley, Anhui, Southeast China, formed in the Luzong Cretaceous volcanic basin at ~130 Ma. We examined a temporal–spatial and potential genetic link between these deposits based on stratigraphic lithofacies sections, biotite and clinopyroxene mineralogical chemistry, zircon chronology, Hf isotopes, and trace elements. Stratigraphy, petrology, mineralogical chemistry, and available fluid inclusion results support that the emplacement depth of the Nihe ore-related porphyry is shallower than that of the Shaxi porphyry. The magmatic zircon and hydrothermal zircon from Nihe provided U–Pb ages of 130.6 ± 0.7 Ma and 130.7 ± 0.7 Ma, respectively. The magmatic zircon U–Pb age (130.0 ± 0.8 Ma) of Shaxi overlaps with its molybdenite Re–Os age (130.0 ± 1.0 Ma). The agreement between the mineralization and porphyry emplacement ages of Nihe and Shaxi indicates a temporal coincidence and supports a possible genetic link between the two deposits, considering their close spatial relationship (in the same ore district, 15 km). The zircon Hf isotopes and trace elements support the evolution of both deposits from an enriched lithospheric mantle, although the Shaxi deposit may have experienced contamination of the Jiangnan-type basement. Both deposits lie above the fayalite-magnetite-quartz buffer, but the Nihe magmatic zircons are of lower temperature and less oxidized than that of Shaxi. The much higher Eu/Eu* and Yb/Dy values of zircons from Shaxi are likely caused by the suppression of early plagioclase crystallization and the prevalence of amphibole fractionation, thus indicating more hydrous content of the Shaxi ore-related magma. Additionally, the Shaxi ore-related porphyry has higher zircon Hf concentrations, suggesting that the porphyry Cu–Au deposit has experienced a greater degree of magma fractionation. Our study highlights that the Nihe IOA deposit and the Shaxi porphyry Cu–Au deposit have a common magma source, while different extent of crust contamination, magma oxidation state, hydrous content, and degree of magma fractionation collectively result in the two distinct ore deposits. This possible genetic link suggests a great potential of porphyry Cu–Au-PGE mineralization in the Middle–Lower Yangtze River metallogenetic belt, especially in the deep part of the IOA district in the Luzong Cretaceous volcanic basin. Full article
Show Figures

Figure 1

41 pages, 10740 KB  
Article
A Multi-proxy Provenance Study of Late Carboniferous to Middle Jurassic Sandstones in the Eastern Sverdrup Basin and Its Bearing on Arctic Palaeogeographic Reconstructions
by Michael A. Pointon, Helen Smyth, Jenny E. Omma, Andrew C. Morton, Simon Schneider, Peter Hülse, Stephen J. Rippington, Berta Lopez-Mir, Quentin G. Crowley, Ian Millar, Martin J. Whitehouse, Dirk Frei, Robert A. Scott and Michael J. Flowerdew
Geosciences 2023, 13(1), 10; https://doi.org/10.3390/geosciences13010010 - 28 Dec 2022
Cited by 3 | Viewed by 3912
Abstract
A multi-proxy provenance study of Late Carboniferous to Middle Jurassic sandstones from the eastern Sverdrup Basin was undertaken employing optical petrography and heavy mineral analysis, chemical analysis of apatite, garnet and rutile grains, as well as detrital zircon U–Pb geochronology and Hf isotope [...] Read more.
A multi-proxy provenance study of Late Carboniferous to Middle Jurassic sandstones from the eastern Sverdrup Basin was undertaken employing optical petrography and heavy mineral analysis, chemical analysis of apatite, garnet and rutile grains, as well as detrital zircon U–Pb geochronology and Hf isotope analysis. Late Carboniferous to Middle Jurassic strata on the southern basin margin are inferred as being predominantly reworked from Silurian to Devonian strata within the adjacent Franklinian Basin succession. Higher-grade metamorphic detritus appeared during Middle to Late Triassic times and indicates exhumation and erosion of lower (Neoproterozoic to Cambrian) levels within the Franklinian Basin succession and/or a direct detrital input from the Canadian-Greenland Shield. The provenance of northern-derived sediments is more enigmatic owing to the subsequent opening of the Arctic Ocean. Northern-derived Middle Permian to Early Triassic sediments were likely derived from proximal areas of the Chukotkan part of the Arctic Alaska-Chukotka microplate. Late Triassic northern-derived sediments have different detrital zircon U–Pb age spectra from Middle Permian to Early Triassic ones and were likely derived from the Uralian orogenic belt and/or the Arctic Uralides. The loss of this sand input during latest Triassic times is interpreted to reflect drainage reorganisation farther upstream on the Barents Shelf. Middle Jurassic sands in the northern and axial parts of the basin were largely reworked from local northern-derived Late Triassic strata. This may have been facilitated by rift flank uplift of the northern basin margin in response to rifting in the adjacent proto-Amerasia Basin. Full article
(This article belongs to the Collection Detrital Minerals: Their Application in Palaeo-Reconstruction)
Show Figures

Figure 1

35 pages, 19706 KB  
Article
Petrogenesis and Metallogenesis of Granitoids in the Yangla Cu-W Polymetallic Deposit, Southwest China: Evidence from Zircon Trace Elements and Hf Isotope
by Xinfu Wang, Bo Li, Guo Tang, Zhen Lei and He Chang
Minerals 2022, 12(11), 1427; https://doi.org/10.3390/min12111427 - 10 Nov 2022
Cited by 11 | Viewed by 2522
Abstract
Magmatic zircon tends to present characteristic trends in trace element compositions in response to magma petrogenesis and metallogenesis, such that zircon may provide a window into melt evolution not accessible by whole rock chemistry. The Yangla large Cu deposit is located in the [...] Read more.
Magmatic zircon tends to present characteristic trends in trace element compositions in response to magma petrogenesis and metallogenesis, such that zircon may provide a window into melt evolution not accessible by whole rock chemistry. The Yangla large Cu deposit is located in the central part of the Jinshajiang Suture Zone, southwest China, constrained between the Jinshajiang and Yangla Faults. In this study, the trace elements and hafnium isotopic compositions of zircons from quartz diorite were studied. Previous published relevant data of Yangla granitoid plutons (i.e., dioritic enclave, granodiorite, and quartz monzonite porphyry) also have been systematically cited and discussed. The result shows that the crystallization temperature and two-stage Hf mode ages (tCDM; the age of the source rocks for the magmas) gradually increased while the oxygen fugacity (fO2) and εHf(t) values gradually decreased, corresponding to the diorite enclave (~232 Ma), through granodiorite (~208 Ma) and quartz monzonite porphyry (~202 Ma), and to quartz diorite (~195 Ma). It is suggested that four plutons were from the same three-component mixing of upper crust + lower crust + mantle magmas, while the upper crustal metasediments ratios were gradually increased from the early to late stage. The increasing upper crust inputs resulted in higher melting temperatures and compositions of the initial magma. All melts experienced distinct fractional crystallization of apatite, titanite, and amphibole, and the later granite melts experienced higher assimilation and fractional crystallization degrees than the early ones in the evolution processes four stages of intrusive rocks. These Yangla granitoids are the products of large-scale acid magmatic emplacement activities in the Triassic-early Jurassic and have a good metallogenic potential of the Cu-W polymetallic deposit. Full article
Show Figures

Figure 1

Back to TopTop