Lithos最新文献

{"title":"Fe and Mg isotopes as tracers of the mantle sources and ore-forming processes of the Xiarihamu magmatic Ni-Cu sulfide deposit","authors":"Qingyan Tang ,&nbsp;Yan Zhang ,&nbsp;Lu Li ,&nbsp;Zhaowei Zhang ,&nbsp;Zhuoming Li ,&nbsp;Wei Liu ,&nbsp;Chi Zhao ,&nbsp;Tengda Yang ,&nbsp;Tianyu Qin","doi":"10.1016/j.lithos.2025.108095","DOIUrl":"10.1016/j.lithos.2025.108095","url":null,"abstract":"<div><div>Mg and Fe isotopes increasingly are utilized to investigate the origins of magmatic sulfide deposits and interactions between the crust and mantle. However, further evaluation of the validity of using Fe isotopes as a constraint to assess crustal contamination is necessary, particularly using more mafic-ultramafic samples. To address this issue, we analyzed the Mg and Fe isotopic compositions of silicate and sulfide minerals in the Xiarihamu magmatic Ni-Cu sulfide deposit, which has high Ni reserves and is located in the East Kunlun Orogenic Belt. The clinopyroxene and orthopyroxene separates from the Xiarihamu deposit have δ⁵⁶Fe values of −0.048 ‰ to +0.172 ‰ and a Δ⁵⁶Fe_Cpx-Opx value of 0.068 ‰. The pentlandite separates have δ⁵⁶Fe values of −0.475 ‰ to +0.062 ‰ and Δ⁵⁶Fe_Opx-Pn values of −0.001 ‰ to 0.487 ‰. The clinopyroxene and orthopyroxene separates have δ²⁶Mg values of −0.376 ‰ to −0.141 ‰ and a Δ²⁶Mg_Opx-Cpx value of −0.014 ‰. Most of the δ²⁶Mg values of the silicate minerals align with those of unmodified mantle. The observed Fe and Mg isotope variations of the minerals in this deposit exceed those caused by mantle melting. The δ⁵⁶Fe and δ²⁶Mg values of the mineral separates do not exhibit correlations with the whole-rock loss on ignition (LOI), orthopyroxene Mg/(Mg + Fe) molar ratio, olivine forsterite content, and sulfide δ³⁴S, indicating that post-magmatic hydrothermal alteration, crystallization differentiation, and crustal sulfur addition cannot sufficiently explain the Mg and Fe isotope variations in the Xiarihamu deposit. The δ²⁶Mg and δ⁵⁶Fe values are lower than mantle values, indicating that the mantle source was modified by a carbonate melt. The δ⁵⁶Fe values exhibit a weak positive correlation with the <em>f</em>_O2 value, and the relationship between the Pd tenor and δ⁵⁶Fe value is consistent with the variations in the silicate melt to sulfide liquid mass ratio (R factor), illustrating that the Fe isotope variations in the Xiarihamu deposit were controlled by both the redox conditions and R factor. The Mg-Sr-Nd mixing calculations revealed that crustal assimilation was crucial for triggering the sulfide saturation in the Xiarihamu deposit. Therefore, Fe isotopes may be unsuitable for identifying crustal contamination; however, when combined with Mg isotopes, they can be useful in determining the mantle sources and metallogenic processes in igneous Ni-Cu mineralization systems. These findings have important implications for future research on the formation of Ni-Cu sulfide deposits, and the mechanisms of Fe isotope fractionation.</div></div>","PeriodicalId":18070,"journal":{"name":"Lithos","volume":"508 ","pages":"Article 108095"},"PeriodicalIF":2.9,"publicationDate":"2025-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143890580","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Recycling ancient refractory peridotites causing the crust-mantle decoupling of the Xigaze ophiolite (South Tibet): New constraints from the Buma mantle massif","authors":"Jia-Ning Zhu ,&nbsp;Chuan-Zhou Liu ,&nbsp;Wei-Qi Zhang ,&nbsp;Tong Liu ,&nbsp;Chang Zhang ,&nbsp;Xiao-Ni Li ,&nbsp;Zhen-Yu Zhang","doi":"10.1016/j.lithos.2025.108090","DOIUrl":"10.1016/j.lithos.2025.108090","url":null,"abstract":"<div><div>Thin oceanic crust coexisting with refractory peridotites is increasingly documented along mid-ocean ridges. This crust-mantle decoupling has been attributed to the recycling of ancient refractory peridotites underneath the ridges. However, the extent to which such recycling has influenced crustal accretion in ancient ocean basins remains inadequately explored. The Xigaze ophiolite in southern Tibet, a major fragment of Neo-Tethyan oceanic lithosphere, is characterized by its thin crust juxtaposed with thick mantle sections. This study presents geochemical, highly siderophile element (HSE), and <em>Re</em>-Os isotopic data from the Buma mantle massif in the western Xigaze ophiolite. The Buma peridotites display a wide range of whole-rock and mineral compositions, with Al₂O₃ contents of 0.5–2.2 wt% and spinel Cr# [=100 × Cr/(Cr + Al)] of 15–60. Rare earth element patterns in whole rocks and pyroxenes suggest that the Buma lherzolites and harzburgites were formed by 5–8 % and 12–19 % melting of a depleted mid-ocean ridge basalt mantle source, respectively. Moreover, these peridotites display uniform HSE patterns, with Ru/Ir and Pt/Pd ratios resembling typical abyssal peridotites, and exhibit mostly unradiogenic ¹⁸⁷Os/¹⁸⁸Os ratios (0.1225–0.1326), yielding <em>Re</em>-depletion ages up to 0.9 Ga. Our results, in combination with published data, suggest that all Xigaze mantle massifs were formed by anhydrous melting beneath the Neo-Tethyan ocean ridge without evidence of sub-arc hydrous melting. The high melting degrees (15 ± 3 %) recorded in the Xigaze ophiolitic peridotites are inconsistent with the mapped thin crusts (&lt;3 km) if all melting occurred beneath the paleo-ridge. Instead, this crust-mantle decoupling is best explained by recycling of ancient mantle, which appears essential in triggering magma-starved seafloor spreading.</div></div>","PeriodicalId":18070,"journal":{"name":"Lithos","volume":"508 ","pages":"Article 108090"},"PeriodicalIF":2.9,"publicationDate":"2025-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143825555","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mesozoic crust-mantle interaction in the East Kunlun Orogenic Belt, northern Tibetan Plateau: Constraints from the Tuolahai granodiorite and MMEs","authors":"Qiwen Dai ,&nbsp;Yunpeng Dong ,&nbsp;Dengfeng He ,&nbsp;Shengsi Sun ,&nbsp;Bo Hui ,&nbsp;Bin Zhang ,&nbsp;Zengshuai Zuo ,&nbsp;Fubao Chong ,&nbsp;Qingxing Luo ,&nbsp;Jinyu Xiao","doi":"10.1016/j.lithos.2025.108093","DOIUrl":"10.1016/j.lithos.2025.108093","url":null,"abstract":"&lt;div&gt;&lt;div&gt;Crust-mantle interaction occurs widely in orogenic belts, exerting a crucial role in understanding the petrogenesis of igneous rocks and the geodynamic processes of orogenic evolution. The East Kunlun Orogenic Belt (&lt;em&gt;E&lt;/em&gt;-KOB), as a typical subduction-accretionary orogenic belt, underwent a prolonged subduction-accretionary evolutionary process from the Early Paleozoic to the Triassic, accompanied by multi-stage magmatic activity. A set of granodiorites with mafic microgranular enclaves (MMEs) outcropped in the Tuolahai of the Central Kunlun Belt is key to revealing the crust-mantle interaction correlated with subduction or collision in the &lt;em&gt;E&lt;/em&gt;-KOB. In this study, petrological, mineral chemical, whole-rock and isotopic geochemical, and geochronological investigations were conducted on the Tuolahai host granodiorites and MMEs to investigate their petrogenesis, magma source, and tectonic significance. The zircon U&lt;img&gt;Pb geochronology suggests comparable crystallization ages of 247 ± 2 Ma and 246 ± 2 Ma for the host granodiorite and MMEs, respectively. The host granodiorites are primarily composed of medium-to-coarse plagioclase, amphibole, quartz and biotite. Geochemically, they exhibit calc-alkaline and metaluminous, with enrichment in LILEs, and slight depletion in HFSEs, belonging to I-type granites. They display negative ε&lt;sub&gt;Nd&lt;/sub&gt;(t) (−5.89 to −5.27) and ε&lt;sub&gt;Hf&lt;/sub&gt;(t) (−4.77 to −2.25), along with comparatively young two-stage Nd and Hf model ages (1.44–1.49 Ga and 1.41–1.57 Ga, respectively). These geochemical features suggest that the granodiorites originated predominantly from juvenile mafic lower crust, with contributions from deep mantle-derived materials, while experiencing minor upper crustal contamination during their ascent. Compared to the granodiorites, the MMEs exhibit a finer-grained texture composed of plagioclase, amphibole, biotite and quartz. Geochemically, they display lower SiO&lt;sub&gt;2&lt;/sub&gt; (50.12–54.13 wt%), higher MgO (4.13–5.29 wt%), ΣREE contents, similar rare earth element patterns, and ε&lt;sub&gt;Nd&lt;/sub&gt;(t) (−5.59 to −5.10), but distinctly different ε&lt;sub&gt;Hf&lt;/sub&gt;(t) (−7.68 to −0.14) values. Considering that the sharp contact, the plagioclase and amphibole xenocrysts in the MMEs are compositionally similar to those in the host rock, we propose that the MMEs represent products of magma mingling, with their sources primarily originating from mantle materials, indicating formation through the partial melting of an enriched lithospheric mantle. Comprehensive petrology, geochemistry and mineral chemistry indicate that the Tuolahai batholith is a product of crust-mantle interaction, where the upwelling of enriched lithospheric mantle led to partial melting of the mafic lower crust, forming hybrid magma and MMEs. Together with the regional geological data, all the above lines of evidence allow us to propose that the Tuolahai granodiorites and the associated MMEs were formed through crust-mantle intera","PeriodicalId":18070,"journal":{"name":"Lithos","volume":"508 ","pages":"Article 108093"},"PeriodicalIF":2.9,"publicationDate":"2025-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143828609","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Unusual glaucophane and winchite-bearing veins in mafic eclogites of the Sesia-Lanzo Zone (Italian Northwestern Alps): Are they due to hydrofracturing or a paleoseismic event?","authors":"Silvana Martin ,&nbsp;Paola Tartarotti ,&nbsp;Gaston Godard ,&nbsp;Omar Bartoli","doi":"10.1016/j.lithos.2025.108067","DOIUrl":"10.1016/j.lithos.2025.108067","url":null,"abstract":"<div><div>The mafic eclogites of the Sesia-Lanzo Zone exposed in the Gressoney valley (Northwestern Alps, Italy) are cut across by unusual dark blue veins, which can be interpreted as due to frictional melting and/or hydrofracturing in the Alpine subduction zone. We combine optical and electron microscopy, EBSD analysis, microprobe and bulk-rock chemical analyses, as well as pseudosection modelling to study these veins, in order to constrain their textural characteristics and <em>P-T</em> evolution together with those of the host eclogite. The eclogite is composed of omphacite, garnet, quartz, white mica, and rutile that equilibrated at <em>P-T</em> conditions of ca. 25 kbar and 570 °C. The veins are cm thick to capillary and up to few metres long; they are filled with very fine-grained fibrous blue amphiboles (glaucophane, winchite, katophorite) in the centre, and blue-green Ca and Ca-Na amphiboles + albite at the margins. Pseudosection modelling suggests that the latters froze at a higher temperature than the formers, suggesting a “chilled margin” effect. The amphibole microcrystals in the vein centre mimick a fluidal texture with convoluted and turbulent flow structures, as if crystallised from a melt; in addition, amphiboles show a strong CPO of the [001] axis parallel to the vein walls. The host eclogite near the veins is strongly fractured as like as the clasts inside the veins. Other blue amphibole veins show a composite evolution with a crystallisation of blocky quartz in the core, consistent with hydrofracturing process. The crystallisation of Na- and Ca-Na amphiboles in the Lillianes veins was assisted by fluid circulation under blueschist-facies conditions, at pressures of about 8–15 kbar, during the exhumation soon after the eclogite-facies peak reached by the host rock in a paleoseismic scenario. Finally, the veins were cut across by late calcite, albite and chlorite veinlets formed under greenschist-facies conditions during exhumation.</div></div>","PeriodicalId":18070,"journal":{"name":"Lithos","volume":"508 ","pages":"Article 108067"},"PeriodicalIF":2.9,"publicationDate":"2025-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143859935","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Geochemistry and radiogenic isotopes constrain the mantle source region of the Mountain Pass Intrusive Suite, California","authors":"Erin K. Benson ,&nbsp;Kathryn E. Watts ,&nbsp;Ian W. Hillenbrand","doi":"10.1016/j.lithos.2025.108060","DOIUrl":"10.1016/j.lithos.2025.108060","url":null,"abstract":"<div><div>The Mountain Pass carbonatite stock is the largest rare earth element (REE) deposit and only active REE mine in the United States. The carbonatite intrusion and spatially associated alkaline silicate intrusions constitute the Mountain Pass Intrusive Suite, which is located within the Mojave Province in California. Both the carbonatite and the alkaline silicate rocks are enriched in large ion lithophile elements and light REEs, and less enriched to depleted in high field strength elements, indicating the mantle source region was metasomatically enriched in incompatible trace elements. The cause of this metasomatic mantle enrichment and the genetic relationship between the carbonatite and the alkaline silicate stocks are poorly understood. In this study, major and trace element geochemical data and isotopic (Rb-Sr, Sm-Nd, and Lu-Hf) data are presented to constrain genesis of the Mountain Pass Intrusive Suite, from mantle source region to the intrusion of the stocks. Our geochemical data are consistent with derivation of the alkaline silicate and carbonatite melts through partial melting from a shared mantle source region rather than through liquid immiscibility or fractional crystallization and separation of a carbothermal fluid. Although the Rb-Sr isotopic system in the Mountain Pass Intrusive Suite is disturbed at the whole-rock scale, the isotopic systems for whole-rock Sm-Nd (εNd_<em>i</em> =  ‐2.2 ± 0.8) and zircon Lu-Hf (εHf_<em>i</em> = 0.1 ± 1.1) are robust and support mantle derivation of the magmas. Geochemical modeling using experimentally derived partition coefficients was used to identify possible causes of enrichment in incompatible elements through metasomatism in the mantle source region. Modeling of metasomatism by melts derived by partial melting of deeply subducted carbonated sediments approximates observed Mountain Pass Intrusive Suite trace element chemistry. Scattered εHf_<em>i</em> in inherited zircon (2.8 ± 2.6) is consistent with derivation from an arc-related environment with substantial crustal contamination. Paleotectonic studies in the Mojave Province indicate that regional subduction preceded emplacement of the Mountain Pass Intrusive Suite by ∼300 Ma. Melting of the Mountain Pass source region may have been caused by post-collisional thermal relaxation and extension.</div></div>","PeriodicalId":18070,"journal":{"name":"Lithos","volume":"508 ","pages":"Article 108060"},"PeriodicalIF":2.9,"publicationDate":"2025-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143823468","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Archean syenites by intracrustal processes: The Boesmanskop Alkaline Complex, Eastern Kaapvaal Craton","authors":"Marcel V.S. Leandro ,&nbsp;Gary Stevens ,&nbsp;Jean-François Moyen ,&nbsp;Alexander F.M. Kisters ,&nbsp;Alanielson Ferreira","doi":"10.1016/j.lithos.2025.108089","DOIUrl":"10.1016/j.lithos.2025.108089","url":null,"abstract":"&lt;div&gt;&lt;div&gt;Alkaline rocks are volumetrically a minor component of the geological record, with Archean examples being remarkably rare. The oldest Archean syenites on Earth occur in the ca. 3.1 Ga Boesmanskop Alkaline Complex (BAC), located on the eastern margin of the Kaapvaal Craton, where they form part of a voluminous Granodiorite-Monzogranite-Syenogranite suite (GMS). The unique geochemical and isotopic characteristics of the BAC may provide key insights into early crustal differentiation processes and the nature of Archean magmatism. Understanding its petrogenesis helps to refine models of early continental stabilization and the evolution of high-K magmatism in the Archean. The rocks of the BAC include syenite, quartz monzonite, and leucogranite. This study draws upon newly acquired data, encompassing field observations, petrological analysis, mineral chemistry, whole-rock geochemistry including Rb&lt;img&gt;Sr and Sm&lt;img&gt;Nd isotope ratios, and phase equilibrium modeling, with the aim of better understanding the petrogenesis of the BAC rocks. These syenitic rocks display coarse-grained porphyritic textures with K-feldspar phenocrysts as cumulus phase and clinopyroxene, Ca-amphibole, plagioclase, titanite, and scarce quartz as the main intercumulus phases. The syenite is only deformed at the contact with the Tonalite–Trondhjemite–Granodiorite (TTG) basement, displaying SC fabrics and mineral lineation parallel with the pluton edges and concordant with the basement kinematic indicators. In other outcrops, the syenite intrudes the TTGs with sharp contacts and overlay syenitic dyke swarms connected to sill intrusions with hypabyssal textures, which suggest the shallow emplacement of the magmas along an active shear zone. The BAC rocks are silica-saturated with high K&lt;sub&gt;2&lt;/sub&gt;O + Na&lt;sub&gt;2&lt;/sub&gt;O (&lt; 11.2 wt%), low MgO (&lt; 1.6 wt%) and low CaO (&lt;3.41 wt%). They also have low transition element contents, high Ba and Sr contents and negative Nb, Ta, and Ti anomaly, indicative of crustal sources. The BAC rocks have Sr and Nd isotopic compositions that overlap those of the host TTG basement. The data obtained indicate that the syenites represent K-feldspar-dominated crystal cumulates left behind by the extraction of rhyolitic melts from the magma chamber, formed from magmas that crystallized high-temperature K-feldspar before plagioclase and quartz. The viability of this hypothesis has been tested by phase equilibrium modeling, which has demonstrated that a subset of GMS granite compositions with high K&lt;sub&gt;2&lt;/sub&gt;O + Na&lt;sub&gt;2&lt;/sub&gt;O (&gt; 9.3 wt%) do produce high-temperature K-feldspar as the first tectosilicate when cooling under low-pressure conditions. Thus, the syenitic cumulates are proposed to be produced by a structurally assisted accumulation of K-feldspar from hot granitic magma produced by fluid-absent anatexis of the lower crust, contributing to the craton stabilization by the transfer of radioactive elements to shallow depths.&lt;/div&gt;&lt;/di","PeriodicalId":18070,"journal":{"name":"Lithos","volume":"508 ","pages":"Article 108089"},"PeriodicalIF":2.9,"publicationDate":"2025-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143881953","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Petrogenesis and tectonic significance of the late Middle Triassic I-type granite in the eastern section of the North Qilian tectonic belt: Constraints on the initiation of post-collision between North China Block and South China Block","authors":"Liang'e Chen ,&nbsp;Zuochen Li ,&nbsp;Xianzhi Pei ,&nbsp;Shaowei Zhao ,&nbsp;Meng Wang ,&nbsp;Hai Zhou ,&nbsp;Lei Pei ,&nbsp;Youxin Chen ,&nbsp;Shang Ji ,&nbsp;Weiyi Hou","doi":"10.1016/j.lithos.2025.108081","DOIUrl":"10.1016/j.lithos.2025.108081","url":null,"abstract":"<div><div>A significant number of Triassic granitic plutons are exposed at the junction of the Qinling and Qilian Orogenic Belts. The Early Triassic to early Middle Triassic granites are distributed in a linear or zonal fashion, trending northwest–southeast, which aligns with the regional tectonic lines. In contrast, the late Middle Triassic to Late Triassic granites exhibit a more diverse distribution, appearing as isolated points or planes that are not constrained by tectonic unit boundaries. These granites provide essential insights into the tectonic evolution of the Qinling Orogenic Belt and the junction of the Qinling and Qilian Orogenic Belts during the Triassic. In this study, we conducted petrological, geochemical, zircon U<img>Pb dating, and Lu<img>Hf isotope analyses for Longyang I-type monzogranite located in the eastern section of the North Qilian Tectonic Belt. The results indicate that the crystallization age of the Longyang pluton is 237.6 ± 1.3 Ma, corresponding to an emplacement age in the late Middle Triassic. The Longyang pluton belongs to metaluminous (A/CNK = 0.88 to 0.97) and high-K calc-alkaline series. The pluton displays an enriched large-ion lithophile elements and light rare earth elements, depleted high field strength elements and heavy rare earth elements pattern, with no significant Eu anomaly. The Hf isotopic composition of the Longyang pluton reveals ε_Hf(t) values ranging from −5.4 to −0.8, with a two-stage model age (<em>T</em>_DM2) between 1291 and 1580 Ma, indicating that its magmatic source is derived from the partial melting of the Mesoproterozoic thickened lower crust. Combined with the mineralogy, geochemical features and regional tectonic background, we propose a post-collision setting. These findings indicate that the subduction of the A'nimaque–Mianlue Ocean had completed around 237 Ma, marking the onset of a comprehensive transition from compression to extension stage for the North China Block and the South China Block. Furthermore, they suggest that the eastern section of the North Qilian Tectonic Belt entered the post-collision initiation stage in the late Middle Triassic.</div></div>","PeriodicalId":18070,"journal":{"name":"Lithos","volume":"508 ","pages":"Article 108081"},"PeriodicalIF":2.9,"publicationDate":"2025-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143817162","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The magmatic to hydrothermal evolution in the Weilasituo Sn-polymetallic deposit, NE China: Insights from quartz texture and trace elements","authors":"Xin Wang ,&nbsp;Nan Qi ,&nbsp;Chang-Zhi Wu ,&nbsp;Xin-You Zhu ,&nbsp;Xi-Heng He ,&nbsp;Xiao-Hua Deng","doi":"10.1016/j.lithos.2025.108091","DOIUrl":"10.1016/j.lithos.2025.108091","url":null,"abstract":"<div><div>Global tin resources are dominantly sourced from granite-related deposits formed through cassiterite precipitation. However, the mechanisms controlling metal enrichment remain unclear. Quartz commonly spans the entire evolution of magmatic-hydrothermal tin deposits capturing geochemical fingerprints. Here, we integrate cathodoluminescence (CL) textural analysis with laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) of quartz from the Weilasituo giant Sn-polymetallic deposit in northeastern China to decode the tin enrichment process. Five quartz types (Q1 to Q5) were identified across the magmatic period to the hydrothermal stage. From quartz of potassic granite (Q1a) to Nb-Ta mineralization albitized granite (Q1b) and Sn-Zn mineralized albitized granite (Q1c), the Al/Ti and Ge/Ti ratios increase and Ti contents decrease indicating a higher degree of magmatic differentiation with temperature decreasing. Sulfide droplets and snowball-textured quartz in Sn-Zn mineralized albitized granite indicate fluid saturation and exsolution from the silicate melt. This corresponds to vertically zoned Sn enrichment in quartz from deep potassic-altered granite (median 0.24 ppm) through intermediate Nb-Ta-mineralized albitized granite (0.24 ppm) to shallow Sn-Zn-mineralized albitized granite (0.29 ppm). Moreover, quartz within the greisen (Q3) records the magmatic-hydrothermal transition, exhibiting significantly higher Sn concentrations (0.76 ppm) compared to those in Q1 (0.18-0.29 ppm). This demonstrates enhanced metal scavenging efficiency during fluid exsolution. Shallow quartz vein (Q5*) exhibits increased Sn and Ge contents and decreased Al/Ti and Ge/Ti ratios relative to deep veins (Q5), demonstrating cooling facilitates cassiterite precipitation. Quartz trace elements indicate that highly differentiated magma, high fluid extraction efficiency, and fluids cooling collectively enabled tin deposition. Furthermore, quartz Sn signatures could be a proxy in targeting Sn mineralization.</div></div>","PeriodicalId":18070,"journal":{"name":"Lithos","volume":"508 ","pages":"Article 108091"},"PeriodicalIF":2.9,"publicationDate":"2025-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143834249","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fragmentation, flow localization, and mingling in a magma transfer zone","authors":"J.H. Kruhl ,&nbsp;R.H. Vernon ,&nbsp;I. Zibra ,&nbsp;S. Biswas","doi":"10.1016/j.lithos.2025.108092","DOIUrl":"10.1016/j.lithos.2025.108092","url":null,"abstract":"<div><div>Meso- and microstructures provide evidence of the fragmentation, mingling, mixing and crystallization history of dioritic, tonalitic and leucogranite magmas in the Abbartello area, Corsica. Flow and ascent led to steep, E–W striking magmatic layering and foliation, and to a sub-vertical magmatic lineation. Crosscutting relationships reflect an intrusion sequence from diorite to tonalite and leucogranite. Upward flow and mingling of these magmas during shortening led to a large variety of magmatic structures. The mingled diorite–tonalite–granite sequence represents a km-sized magma transfer zone within a late-Variscan intrusive suite in southern Corsica.</div></div>","PeriodicalId":18070,"journal":{"name":"Lithos","volume":"508 ","pages":"Article 108092"},"PeriodicalIF":2.9,"publicationDate":"2025-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143834250","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The role of evaporite in iron oxide-apatite ore deposit formation: Constraints of the late Miocene Abovyan deposit, Armenia","authors":"Nikolai Nekrylov ,&nbsp;Samvel Hovakimyan ,&nbsp;Khachatur B. Meliksetian ,&nbsp;Ervin Veress ,&nbsp;Christian A. Bergemann ,&nbsp;Karen Hambaryan ,&nbsp;Massimo Chiaradia ,&nbsp;Arman Vardanyan ,&nbsp;Gevorg Navasardyan ,&nbsp;Alina Korneeva ,&nbsp;Vadim S. Kamenetsky ,&nbsp;Robert Moritz","doi":"10.1016/j.lithos.2025.108078","DOIUrl":"10.1016/j.lithos.2025.108078","url":null,"abstract":"<div><div>Iron Oxide–Apatite (IOA) deposits are a notable source of iron, and, potentially, of phosphorus and rare earth elements (REE). The vast majority of these deposits are ancient (from ∼1900 to ∼100 Ma), and their original textures and mineral associations are overprinted by regional and local metasomatic/metamorphic processes. In the present paper, we provide new petrographic, mineralogical and geochemical data on the poorly studied Abovyan IOA deposit in Armenia, one of the world's youngest IOA deposits. The Late Miocene magnetite-apatite Abovyan deposit is hosted by a subvolcanic andesite body located in the volcanic zone of Gegham Highland. The ore mineralization is hosted in andesite and consists of disseminated magnetite‑carbonate blobs, breccia and massive magnetite-apatite bodies. Disseminated blobs mostly consist of magnetite-clinopyroxene-dolomite-hematite-calcite assemblages, whereas the mineralogical diversity increases toward the massive ore bodies with the appearance of Th- (thorite, monazite) and REE-rich (monazite, REE-silicates) minerals. Abundant inclusions of halite and sylvite were also found in magnetite from massive ore. Massive magnetite-apatite ore is depleted in Rb, Ba, K, Sr and HFSE and enriched in REE, Th, U and Pb relative to host andesite. The host rocks have more radiogenic ⁸⁷Sr/⁸⁶Sr ratios of ∼0.7053 than other volcanic rocks in the Gegham highland with ratios of ∼0.7042. The apatite from nine ores samples have even more radiogenic ⁸⁷Sr/⁸⁶Sr ratios of ∼0.706 for the same εNd values. These data allow us to conclude that ore formation is likely linked to liquid immiscibility triggered by the assimilation of Sr-rich and Nd-poor crustal material. The local source for such assimilated material is the K-rich evaporite of the Yerevan salt basin.</div></div>","PeriodicalId":18070,"journal":{"name":"Lithos","volume":"508 ","pages":"Article 108078"},"PeriodicalIF":2.9,"publicationDate":"2025-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143800606","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}