Mineralium Deposita最新文献

{"title":"Nonsulfide Zn–Pb mineralization and vertical zoning in the world-class Angouran deposit, NW Iran: linked to water table-controlled supergene processes","authors":"Liangliang Zhuang, Yucai Song, Yingchao Liu, Teng Deng, Zengqian Hou","doi":"10.1007/s00126-025-01372-w","DOIUrl":"https://doi.org/10.1007/s00126-025-01372-w","url":null,"abstract":"<p>This study reevaluates the previously proposed hypogene hypothesis and redefines the origin of smithsonite mineralization in the Angouran deposit, Iran (4.7 Mt of sulfide ore at 27.7% Zn; 14.6 Mt of carbonate ore at 22% Zn). Geological mapping and petrological observations reveal a distinct vertical mineralized zoning: a lower primary sulfide zone containing minor amounts of smithsonite, an intermediate transition zone characterized by smithsonite and newly formed sulfides, and an upper oxidation zone comprising smithsonite and Fe–Mn oxides, which is widely recognized as supergene origin under atmospheric oxygen fugacity conditions. This zoning pattern is analogous to classic supergene weathering profiles observed in porphyry Cu deposits. Morphological and sulfur isotopic analyses (³⁴S-depleted signatures) confirm that the newly formed sulfides within the transition zone are of supergene origin, primarily induced by bacterial sulfate reduction processes and partly formed by the direct replacement of primary sphalerite immediately below the paleo-water table. Smithsonite from all three zones exhibits similar C–O isotopic compositions that fall between those of the host marble and travertines, further supporting a consistent supergene origin. Reaction path modeling demonstrates that smithsonite cannot be generated by the direct replacement of sphalerite by CO₂-rich spring water unless under atmospheric oxygen fugacity conditions. The development of the vertical zoning with distinct mineral assemblages is primarily controlled by the position of the paleo-water table. Near it, rapid fluctuations in oxygen fugacity and sulfur fugacity occur, allowing sulfides formed under reducing conditions to coexist with smithsonite precipitated in relatively oxidative environments. The occurrence of supergene sulfides provides valuable insights into the origin of nonsulfide Zn–Pb mineralization and aid in locating deeply buried primary sulfide orebodies.</p>","PeriodicalId":18682,"journal":{"name":"Mineralium Deposita","volume":"132 1","pages":""},"PeriodicalIF":4.8,"publicationDate":"2025-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144066945","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":"Cassiterite U–Pb ages from the Tin Islands, Indonesia, the southern end of the Southeast Asian tin province","authors":"Jie-Hua Yang, Rui-Zhong Hu, Mei-Fu Zhou, Bernd Lehmann, Jun-Hong Zhao, Jing-Hua Wu, Liang Liu, Wei Mao, Zheng-Teng Cui, Mega Fatimah Rosana","doi":"10.1007/s00126-025-01373-9","DOIUrl":"https://doi.org/10.1007/s00126-025-01373-9","url":null,"abstract":"<p>The Tin Islands of Indonesia (Riau Archipelago, Bangka and Belitung) constitute the southernmost part of the SE Asian tin province. U–Pb ages of cassiterite from three granite-related tin deposits (Pemali, Selumar and Tikus) and four placer tin deposits (Penyusuk, Sadab Perlang, Gunung Mudal Sincong and Riding Panjang) on Bangka and Belitung Islands were determined by in situ LA-ICPMS U–Pb dating. Cassiterite from the Pemali, Selumar and Tikus deposits has ²³⁸U/²⁰⁶Pb lower intercept U–Pb ages (2 s) of 217.2 ± 2.9 Ma, 223.7 ± 1.6 Ma and 212.5 ± 3.3 Ma, respectively. Alluvial cassiterite from the placer tin deposits of Penyusuk, Sadab Perlang, Gunung Mudal Sincong and Riding Panjang gave U–Pb ages (2 s) of 225.4 ± 3.6 Ma, 216.9 ± 4.2 Ma, 230.1 ± 2.5 Ma and 222.7 ± 1.4 Ma, respectively. These dates define the age of 230—210 Ma for tin mineralization in the Tin Islands, in alignment with the metallogenic ages of tin deposits in the Main Range belt of Malaysia and Thailand.</p>","PeriodicalId":18682,"journal":{"name":"Mineralium Deposita","volume":"35 1","pages":""},"PeriodicalIF":4.8,"publicationDate":"2025-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143931193","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":"Lithium-caesium-tantalum pegmatites in the Varuträsk area, Sweden: geological setting, timing, and source-transport-trap characteristics","authors":"Joel B. H. Andersson, Edward P. Lynch, Diana Schildger, Heejin Jeon, Martiya Sadeghi, Tobias E. Bauer","doi":"10.1007/s00126-025-01369-5","DOIUrl":"https://doi.org/10.1007/s00126-025-01369-5","url":null,"abstract":"&lt;p&gt;This study investigates lithium-caesium-tantalum (LCT) pegmatites and associated pegmatites and granites in the Varuträsk area, northern Sweden, using a mineral systems approach (i.e. source-transport-trap). The research incorporates geological mapping both regionally and underground, analysis of geological structures and host rock competency, 3D modelling, lithogeochemistry, and zircon-monazite U–Pb SIMS geochronology to assess the genesis and controls on the Varuträsk LCT pegmatite system. The findings reveal four phases of intrusive magmatism within a supracrustal package predominantly composed of metagreywacke, metabasalt (amphibolite), and black shale, subjected to two fabric-forming deformation phases and at least two folding phases, pre- and syn-plutonism in association with the Svecokarelian orogeny. Pegmatites are controlled by brittle to brittle-plastic structures that intersect the tectonic fabric of the host rock, with host rock competency, characterized by uniaxial compressive strength, being a key factor determining the intrusion angle of the pegmatite. The earliest magmatic phase in the area is represented by a granodiorite pluton with a zircon &lt;sup&gt;207&lt;/sup&gt;Pb/&lt;sup&gt;206&lt;/sup&gt;Pb age of 1885 ± 3.2 Ma, linked to the main Svecokarelian orogenic cycle. A granodiorite-tonalite intrusion related to the Transscandinavian Igneous Belt has a zircon &lt;sup&gt;207&lt;/sup&gt;Pb/&lt;sup&gt;206&lt;/sup&gt;Pb age of 1801 ± 1.7 Ma. Three peraluminous S-type granites (plutonic Skellefte suite) yielded zircon &lt;sup&gt;207&lt;/sup&gt;Pb/&lt;sup&gt;206&lt;/sup&gt;Pb ages of 1795 ± 1.7 Ma and 1792 ± 1.6 Ma, and a monazite &lt;sup&gt;207&lt;/sup&gt;Pb/&lt;sup&gt;206&lt;/sup&gt;Pb age of 1798 ± 4.6 Ma. Small and irregular to elongated bodies of hypabyssal pegmatitic leucogranite with peraluminous characteristics (hypabyssal Skellefte suite), although not dated in this study, form a geochemical continuum with the Varuträsk LCT pegmatite and less evolved regional pegmatites, and are chemically distinct from the larger S-type plutons. A ‘simple’ muscovite pegmatite dyke, representative of the less evolved regional pegmatites in the area, produced a monazite U–Pb crystallisation age of 1780 ± 6.9 Ma. These results suggest that the hypabyssal pegmatitic leucogranites, regional less evolved pegmatites, and the Varuträsk LCT pegmatite represent the final stage (c. 1.78 Ga) of crustal maturation in the orogenic cycle, marginally postdating the regional migmatization and S-type granite plutonism event. However, further research is encouraged in this study to validate the time gap between plutonic and pegmatitic granites in the Varuträsk area. We propose a mineral system model encompassing a c. 1.80 – 1.78 Ga timeframe that involved initial anatexis of metasedimentary rocks to form S-type granite plutons during the late Svecokarelian orogeny. Subsequently, a resolvable younger magmatic event generated granitic pegmatite melts that utilized pre-existing structures as transport pathways. These melts were trapped in structurally fa","PeriodicalId":18682,"journal":{"name":"Mineralium Deposita","volume":"7 1","pages":""},"PeriodicalIF":4.8,"publicationDate":"2025-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143909818","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":"Structural controls on lithium mineralization in shear-zone hosted granitic pegmatites of the Zulu pegmatite field, Zimbabwe – implications for exploration","authors":"Lot Koopmans, Nicholas J. Gardiner, Brayden St. Pierre, Richard M. Palin, Rutendo Musinga, Laurence J. Robb","doi":"10.1007/s00126-025-01371-x","DOIUrl":"https://doi.org/10.1007/s00126-025-01371-x","url":null,"abstract":"<p>Granitic pegmatites are a significant source of critical metals including tin, tantalum, and most notably lithium. To meet future demand, a comprehensive exploration model is required to assist in the discovery of new hard rock deposits. Whereas recent work has largely focused on understanding the source and mineralization processes of pegmatites, the structural controls on the distribution and size of individual deposits remains poorly understood and understudied. In this contribution, we present a structural study on the Zulu pegmatite field in Zimbabwe, which provides a good example of the influence of shear zones, host rock rheology, and lithological competency contrasts on the orientation, size, and distribution of pegmatite bodies within a pegmatite field. At Zulu, we observe both structural and petrographic evidence for two types of pegmatite emplacement within an active shear zone during D₂ strike-slip dominated deformation. An early generation (Type 1) was emplaced syn-kinematic to D₂ within dilational jogs subparallel to the shear fabric, and continued ductile shearing also drove significant recrystallization which affected the primary magmatic phases and therefore influenced the preserved mineralogy. A later generation (Type 2) was emplaced syn-to-late-kinematic to D₂ along tension gashes and subordinate fracture sets oblique to the shear fabric, which served to truncate the cooling history and preserve a primarily magmatic mineralogy within this pegmatite group. By comparing Zulu to other large pegmatite deposits, we conclude that geologic structures are critical to source-to-sink connectivity in lithium pegmatite systems, and affect the mineralization potential of individual deposits by driving recrystallization. Assessing the structural history and relative timing of emplacement within a pegmatite field, in conjunction with detailed (micro)textural observations from within pegmatite bodies, is essential to understanding pegmatite emplacement geometries. A more systematic approach in constraining these relationships will therefore aid in generating new exploration targets in both greenfield and brownfield settings.</p>","PeriodicalId":18682,"journal":{"name":"Mineralium Deposita","volume":"47 1","pages":""},"PeriodicalIF":4.8,"publicationDate":"2025-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143910664","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":"Defining a Triassic carbonatite-related Mo-(REE) metallogenic belt along the southern margin of the North China Craton","authors":"Sheng-Ren Chang, Xin-Fu Zhao, Jian-Hui Su, Shao-Rui Zhao, Li-Ping Zeng, Carl Spandler","doi":"10.1007/s00126-025-01370-y","DOIUrl":"https://doi.org/10.1007/s00126-025-01370-y","url":null,"abstract":"<p>Carbonatites are important sources of rare metals (e.g., REE, Nb), but are not generally considered prospective for Mo mineralization. Numerous quartz-carbonate-rich vein-type Mo-(REE) deposits and prospects of enigmatic origin extend over 200 km along an E-W belt at the southern margin of the North China Craton (S-NCC). These veins commonly contain carbonates, quartz, sulfates, K-feldspar, sulfides, REE minerals, with minor aegirine-augite and pyrochlore occurring locally. This mineral assemblage is diagnostic of carbonatite-related hydrothermal systems. These veins also show alkali metasomatism, elevated REE contents, sulfate-bearing high-salinity fluid inclusions, and mantle-like isotopic compositions consistent with a carbonatite origin. Two Mo-(REE) mineralization events at ~ 238 Ma and ~ 220 to ~ 210 Ma are recognized based on monazite U-Th-Pb and molybdenite Re-Os isotopic dates acquired from representative deposits across the belt. Combined with previous geochronological data, we propose that these deposits define a Triassic carbonatite-related vein-type Mo-(REE) metallogenic belt in the S-NCC which formed during the syn-collisional to post-collisional period of the Qinling-Dabie Orogenic Belt. The carbonatite-related Mo mineralization formed via a synergistic interplay of three key mechanisms: (1) mantle metasomatism by Mo-rich crustal materials (subducted sediments/delaminated crust) generating fertile metallogenic mantle sources; (2) Mo dissolution and transport in mantle-derived volatile-rich carbonatitic melts and related hypersaline fluids; and (3) Mo enrichment/saturation through fractional crystallization of Mo-deficient phases (carbonates, K-feldspar, sulfates) combined with temperature and redox controlled precipitation processes.</p>","PeriodicalId":18682,"journal":{"name":"Mineralium Deposita","volume":"524 1","pages":""},"PeriodicalIF":4.8,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143893520","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":"Stable (Zn, Cd, Fe) and radiogenic (U, Pb) metal isotope constraints on the age, genesis and modification of the Lovisa Zn-Pb sulfide deposit, Bergslagen, Sweden","authors":"N. F. Jansson, J. Andersson, I. Rodushkin, E. Engström, K. Billström","doi":"10.1007/s00126-025-01367-7","DOIUrl":"https://doi.org/10.1007/s00126-025-01367-7","url":null,"abstract":"<p>We present isotopic data bearing on the origin of the vent-distal, Lovisa stratiform Zn-Pb sulfide deposit, Bergslagen, Sweden. The age of deposition is constrained by secondary ionisation mass spectrometry (SIMS) U–Pb zircon dating of pumiceous mass flow deposits interbedded with mineralised, fine-grained volcaniclastic strata. Two mass flow deposits in the stratigraphic footwall yield ages of 1892 ± 2 Ma and 1892 ± 5 Ma respectively, whereas a mass flow deposit in the stratigraphic hanging wall yields an age of 1891 ± 3 Ma, constraining the mineralisation to c. 1892 Ma. Positively correlated δ⁶⁶Zn (-0.299 to + 0.219‰), δ³⁴S (-0.2 to + 4.7‰) and Zn/Cd (122 to 659) in sphalerite suggest mass-dependent, kinetic fractionation during sulfide deposition. Upwards decrease in these parameters and Zn/Pb relative to stratigraphic younging suggest that the hydrothermal system matured over time, whereby later fluid batches reached the depositional site less fractionated. Thermochemical sulfate reduction and cooling of single hydrothermal fluid batches are suggested as sulfide precipitation mechanisms while bacteriogenic sulfate reduction is deemed less likely based on by absence of highly negative δ¹¹⁴Cd (-0.212 to -0.069‰), and δ³⁴S values. Sphalerite and galena Pb isotope compositions indicate leaching of c. 1.91–1.89 Ga felsic volcanic rocks as a principal metal source followed by subsequent, syn-metamorphic addition of radiogenic Pb. Limited syn-metamorphic isotopic homogenisation is suggested by retained systematic variations in different sulfide beds.</p>","PeriodicalId":18682,"journal":{"name":"Mineralium Deposita","volume":"257 1","pages":""},"PeriodicalIF":4.8,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143872128","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":"Role of mantle dynamics and geochemical diversity in chromitite formation: insights from the Luobusa ophiolite, SW Tibet","authors":"Fahui Xiong, Basem Zoheir, Xiangzhen Xu, Tian Qiu, Weibin Gui, Huidan Xie, Jingsui Yang","doi":"10.1007/s00126-025-01368-6","DOIUrl":"https://doi.org/10.1007/s00126-025-01368-6","url":null,"abstract":"<p>The Luobusa massif within the Yarlung Zangbo Suture Zone (YZSZ) in SW Tibet hosts distinct chromitite types: low-grade, intermediate-grade, and high-grade (massive) ores, each reflecting unique mantle processes and formation conditions. Variations in Cr# and Mg# values in chromian spinels suggest a dynamic magmatic environment influenced by melt-peridotite interactions, gravitational settling, and metasomatic processes, with boninitic melts characteristic of forearc settings playing a significant role in chromitite formation. Isotopic analyses, including δ²⁶Mg, δ⁵⁶Fe, and PGE alloys, suggest high <i>P</i>-<i>T</i> conditions during chromitite genesis, indicating multiple phases of magmatic differentiation and metasomatism. The Re-depletion (<i>T</i>_RD) ages of 1.0–2.2 Ga for the YZSZ peridotites indicate the presence of ancient subcontinental lithospheric mantle, representing the earliest component in the mantle history of the region. These ancient mantle domains were subsequently modified through interaction with convective mantle sources, likely during the breakup of Gondwana. The chromitites, with an age of ~ 340 Ma, align with subduction-related tectonics and mark an early Paleozoic subduction episode. The peridotites, with formation ages spanning 305–376 Ma, reflect a protracted and non-linear mantle evolution influenced by mantle heterogeneity, episodic melt infiltration, and metasomatic alteration. The transition from MORB- to arc-type basaltic magmatism further suggests subduction initiation and slab rollback during this time. However, the Luobusa peridotites appear to have formed during a distinct, younger tectonic episode, possibly linked to an earlier phase of subduction or mantle plume activity. This is supported by the published Sm–Nd isochron age of 177 ± 31 Ma for Luobusa gabbro, pointing to a Mesozoic magmatic event. Re–Os isotopic data from both YZSZ and Luobusa peridotites reveal interactions between S-saturated basaltic melts and the lithospheric mantle, emphasizing the importance of melt-rock interaction and metasomatism during Neo-Tethyan subduction. Collectively, these observations support a multi-stage tectonic model for the evolution of the Neo-Tethys, involving early subduction, plume-related processes, and the recycling of ancient lithospheric materials.</p>","PeriodicalId":18682,"journal":{"name":"Mineralium Deposita","volume":"17 1","pages":""},"PeriodicalIF":4.8,"publicationDate":"2025-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143866399","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":"Granite-pegmatite-related gold skarns and associated Li-Cs-Ta pegmatites in the Archean Yilgarn Craton, Western Australia","authors":"Andreas G. Mueller","doi":"10.1007/s00126-025-01361-z","DOIUrl":"https://doi.org/10.1007/s00126-025-01361-z","url":null,"abstract":"<p>In greenstones of the east-central Yilgarn Craton, Western Australia, Li-Cs-Ta (LCT) pegmatites of the albite-spodumene type (resources &gt; 300 Mt at 1.4% Li₂O) are spatially associated with high-T (650–450 °C) granite-pegmatite-related skarn and skarn-quartz vein Au-Ag deposits (production 580 t Au). U-Pb and Rb-Sr ages (2.65–2.62 Ga) link both the LCT pegmatites and gold deposits to a suite of peraluminous I-type biotite granites, magnetite-series in least-fractionated K-feldspar megacrystic members, and magnetite- or ilmenite-series in pegmatitic garnet-muscovite intrusions contaminated by melt interaction with continental crust. The granite-pegmatite complexes and the gold skarns formed at 11–15 km crustal depth (300–400 MPa) in a post-orogenic batholith environment at the margin of the 2.7 Ga Eastern Goldfields orogen. Gold occurs in both endo- and exoskarn, and in granite and pegmatite dikes. Calcite carbon isotopes, and initial ⁸⁷Sr/⁸⁶Sr ratios in scheelite relate the skarns to post-orogenic intrusions. Inner calcite, pyroxene, and outer biotite, cordierite, amphibole, and olivine impart a CO₂-Ca-Mg-K metasomatic signature to the hydrothermal system (e.g., Nevoria, Yilgarn Star, Copperhead). An exception is the Ghost Crab deposit, where anthophyllite, cummingtonite, and albite are major constituents in sodic gold ore replacing paragneiss in a zone of magnesian skarn. This deposit is proximal to the albite-spodumene pegmatites of the Mt Marion mine. The skarns in the Yilgarn Craton share the granite-pegmatite association, the gangue mineralogy, the Au-Bi-W geochemical signature, and low- to moderate salinity H₂O-CO₂ fluid inclusions with reduced tungsten skarns, and with world-class gold deposits in other Archean cratons (Kaapvaal, Slave, Superior, Dharwar).</p>","PeriodicalId":18682,"journal":{"name":"Mineralium Deposita","volume":"22 1","pages":""},"PeriodicalIF":4.8,"publicationDate":"2025-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143836767","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":"Columbite-tantalite and cassiterite as indicator minerals for lithium pegmatites: implications from geospatial and mineralogical analyses of stream sediments in southeast Ireland","authors":"David Kaeter, Julian F. Menuge","doi":"10.1007/s00126-025-01366-8","DOIUrl":"https://doi.org/10.1007/s00126-025-01366-8","url":null,"abstract":"<p>Hard-rock lithium exploration faces challenges due to less advanced deposit and exploration models compared to commodities like copper. Additional obstacles arise from the glaciated and densely vegetated terrains typical of much of Europe, which present additional obstacles to access and geological mapping. Our research focuses on a belt of LCT (Li-Cs-Ta-rich) spodumene pegmatites on the eastern margin of the Caledonian S-type Leinster Batholith, southeast Ireland. We analyse regional stream-sediment geochemistry data and mineralogy of selected stream-sediment samples. Our goal is to identify signatures of the Leinster LCT pegmatites and draw conclusions for lithium exploration. Our analysis reveals high tantalum and tin in several catchments containing known Leinster spodumene pegmatites before and after lithological background correction. Mineralogical analysis reveals that anomalous Sn and Ta in these stream sediments can be attributed to the presence of columbite-tantalite, tapiolite, microlite, and cassiterite. Through SEM-BSE/-EDS analysis and LA-ICP-MS chemical mapping, we show that these minerals exhibit similar textural and chemical characteristics to their counterparts in spodumene pegmatite drill cores and surface boulders and in similar deposits elsewhere, demonstrating that they are useful indicator minerals for these deposits. We conclude that regional lithium pegmatite and rare-metal granite prospectivity can be assessed by examining Sn-Ta associations in stream sediment data. If regional geology, tectonic setting, and stream-sediment geochemistry indicate prospectivity, more detailed local studies can be conducted. By analysing the mineralogy of regional stream sediment samples, prospective areas can be narrowed down to individual catchments. Local geochemical surveys can then follow to pinpoint mineral sources.</p>","PeriodicalId":18682,"journal":{"name":"Mineralium Deposita","volume":"43 1","pages":""},"PeriodicalIF":4.8,"publicationDate":"2025-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143823020","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":"Cobalt-rich diagenetic Mn-oxide mineralization in the Neogene onshore Pisco Basin, Peru","authors":"Ivana C. Carcamo-Valencia, Lisard Torró, Johan S. Ramírez-Briones, Luis Ayala, Joaquín A. Proenza, Thomas Aiglsperger, Patrice Baby","doi":"10.1007/s00126-025-01364-w","DOIUrl":"https://doi.org/10.1007/s00126-025-01364-w","url":null,"abstract":"<p>Sedimentary basin-hosted manganese oxides may represent an important yet underexplored source of critical metals. Here we present a stratigraphic, textural, mineralogical, and compositional characterization of Mn-oxide nodules, coatings, and veins in the Pisco onshore forearc basin, Peru. The Mn-oxide mineralization is stratabound within marine sandstone, siltstone, and tuff from the Neogene Chilcatay and Pisco formations. X-ray diffraction and electron microprobe analyses identify the Mn oxides as cryptomelane (± hollandite) and todorokite, which cement detrital grains and fossilize biological remains. Bulk chemical analyses of nodules, coatings, and veins reveal significant cobalt enrichment (mean = 0.17 ± 0.15 wt% Co; up to 0.63 wt% Co), corroborated by electron probe microanalysis of individual Mn oxide phases (mean = 0.37 ± 0.33 wt% Co; up to 2.1 wt% Co). The stratigraphic control, biomorphic replacement, mineralogy, and chemical composition collectively indicate a diagenetic origin for the Mn-oxide mineralization. The formation pathway likely involved organic matter decay or brine-hydrocarbon interactions coupled with Mn and Fe reduction, resulting in metal-enriched porewaters that circulated along structures and permeable horizons. Subsequent precipitation under oxygenated conditions occurred during late Pliocene uplift and exposure of the East Pisco Basin. This study demonstrates that diagenetic Mn oxides exposed in onshore basins represent a potential resource for manganese and critical elements such as cobalt.</p>","PeriodicalId":18682,"journal":{"name":"Mineralium Deposita","volume":"11 1","pages":""},"PeriodicalIF":4.8,"publicationDate":"2025-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143814179","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}