Tin Deposits Research Articles

Application of Euler and Werner deconvolution techniques in delineating tin deposit in Okeso area, Southwestern, Nigeria

The Okeso pegmatites field was evaluated using magnetic method within abandoned mining site close to the southeastern region of Ojoku area. The study aims to delineate, identify geological boundaries and determine depth of tin deposits in the area. The acquired magnetic data was enhanced with the combination of 3D Euler and Werner deconvolution methods. Five magnetic profiles were selected and carried out on the residual anomalies around the abandoned mine site at Okeso with three of the profile lines were in the NW-SE direction and two in the NE-SW direction. The residual magnetic anomalies showed the magnetic susceptibilities of ≤ 4.5118 × 10−3 nT in the ore bearing pegmatite within the basement rocks. Results from profiles of Werner deconvolution identified some shallow tectonic structures like fractures, pegmatites and faults which are capable of hosting metallic tin deposits. The depth to the magnetic source varies from a minimum to a maximum of 300 m to 1200 m below the subsurface in all selected profiles, suggesting the shallow nature of the magnetic source in the area. Additionally, the dip angle ranges from 5.60 to 81.20, potentially attributed to Pan-African shallow structures according to the contact model. Solutions obtained from the structural index of contact and dyke reveals the presence of dyke formation and boundaries which separate rocks from one another. The trend of the lineaments/ fractures which were likely established during the Pan-African orogeny is dominant in the NE-SW direction, conforms with the trends obtained for basement structures in previous studies. Depth range produced by 3D Euler deconvolution is from 50 - 1000 m for all the lineaments. This gives an insight of approximate depth range of all the lineaments/ fractures across the whole map in the study area unlike, Werner deconvolution which is profile biased. The identical signature from all profiles implies that the tin deposit is relatively uniform, extending to a great depth in the area. This represents economically viable quantity and makes it a worthy target for investors.

Application of Euler and Werner deconvolution techniques in delineating tin deposit in Okeso area, Southwestern, Nigeria

The Okeso pegmatites field was evaluated using magnetic method within abandoned mining site close to the southeastern region of Ojoku area. The study aims to delineate, identify geological boundaries and determine depth of tin deposits in the area. The acquired magnetic data was enhanced with the combination of 3D Euler and Werner deconvolution methods. Five magnetic profiles were selected and carried out on the residual anomalies around the abandoned mine site at Okeso with three of the profile lines were in the NW-SE direction and two in the NE-SW direction. The residual magnetic anomalies showed the magnetic susceptibilities of ≤ 4.5118 × 10−3 nT in the ore bearing pegmatite within the basement rocks. Results from profiles of Werner deconvolution identified some shallow tectonic structures like fractures, pegmatites and faults which are capable of hosting metallic tin deposits. The depth to the magnetic source varies from a minimum to a maximum of 300 m to 1200 m below the subsurface in all selected profiles, suggesting the shallow nature of the magnetic source in the area. Additionally, the dip angle ranges from 5.60 to 81.20, potentially attributed to Pan-African shallow structures according to the contact model. Solutions obtained from the structural index of contact and dyke reveals the presence of dyke formation and boundaries which separate rocks from one another. The trend of the lineaments/ fractures which were likely established during the Pan-African orogeny is dominant in the NE-SW direction, conforms with the trends obtained for basement structures in previous studies. Depth range produced by 3D Euler deconvolution is from 50 - 1000 m for all the lineaments. This gives an insight of approximate depth range of all the lineaments/ fractures across the whole map in the study area unlike, Werner deconvolution which is profile biased. The identical signature from all profiles implies that the tin deposit is relatively uniform, extending to a great depth in the area. This represents economically viable quantity and makes it a worthy target for investors.

Geochronology and geochemistry of the Banjiaoyuan tin deposit, southern Hunan Province and its geological implications

Situated in the central part of the Southern Hunan segment of the Nanling Metallogenic Belt, the Banjiaoyuan tin deposit represents a significant Indosinian quartz vein type tin deposit. Based on field geological surveys and petrographic observations, the mineralization in the area can be divided into three stages: (I) early greisen stage, (II) cassiterite-quartz vein stage, and (III) late barren quartz vein stage. The dating results show that the 40Ar-39Ar plateau age of muscovite in stage I is 215.51 ± 0.87 Ma, and the Rb-Sr isochronous age of quartz mineral in stage II is 214.2 ± 3.1 Ma (MSWD = 1.3), both of which are coincide with the cassiterite U-Pb lower intercept age (215.7 ± 1.3 Ma, MSWD = 1.2), confirming the existence of metallogenic events in this region during the late Indosinian. The δD and δ18O of quartz in stage II range from −66.2 to −80.2 ‰, and 3.71 to 6.17 ‰, respectively, indicating that the ore-forming fluid is mainly derived from a mixture of magmatic-hydrothermal fluids and a small amount of meteoric water. We applied LA-ICP-MS chemical mapping and trace elements analysis to cassiterites, found that they underwent a transition from oxidation to reduction during precipitation when the fluids tend to be more volatile-rich and highly fractionated. The formation of the Banjiaoyuan tin deposit is closely related to the late Indosinian magmatic activity in the Yangmingshan region. Besides, the deep and peripheral parts of the mining area also have the potential for large-scale vein-type and greisen-type W-Sn mineralization.

Zircon in tin granite as tracer for fluid metasomatism and Sn mineralization

Most tin deposits in the world are genetically related to tin granite and form during complex magmatic-hydrothermal processes. Zircon is a common accessory mineral in granite and related ore systems and can host a number of ore metals, such as Sn, W, Nb, Ta, U and Th, in its crystal lattice. However, whether metal enrichment/depletion can trace ore-forming processes is still unclear. Here, we report that the metal concentrations in various types of zircons from the Mopanshan tin granites in the southern Great Xing'an Range (Northern China) can be used as good indicators of fluid metasomatism and Sn mineralization. Two lithological zones are developed in the Mopanshan pluton, including porphyritic syenogranite (PG) in the center and fine-grained syenogranite (FG) at the margin. Zircons in the PG (PGZ-1, PGZ-2, and PGZ-3) are all magmatic in origin, while zircons in the FG can be categorized into magmatic zircons (FGZ-1 and FGZ-2) and metasomatic zircons (FGZ-3). The PGZ-1 and FGZ-1 grains are transparent prismatic crystals with bright oscillatory zonation, whereas the PGZ-2 grains are murky crystals with dark oscillatory zonation. PGZ-3 and FGZ-2 grains occur as overgrowths of previously formed zircon (PGZ-1, PGZ-2, and FGZ-1) or as brown individual crystals, showing dark and homogeneous cathodoluminescence (CL) textures. The metasomatic FGZ-3 grains are translucent-opaque porous crystals with vermicular CL zonation and commonly replace FGZ-2. The trace element compositions of magmatic zircons are completely melt controlled, providing a record of magmatic evolution as a constant decrease in Zr/Hf ratios and a gradual increase in Th, U, Nb, and Ta contents. Moreover, the structure of magmatic zircons transforms from a crystalline state to an amorphous state as a consequence of radioactive decay of U and Th. A coupled dissolution-reprecipitation process is proposed for the formation of metasomatic FGZ-3. The reactive fluid is the magmatic fluid that exsolved from the melt in the late magmatic stage. The magmatic fluid replaced biotite and rare earth phosphates (mainly monazite and apatite) enclosed within biotite, resulting in significant amounts of Nb, Ta, Sn, P, Al, Ca, Fe, and REEs, which subsequently reacted with the FGZ-2 zircons to leach Th, U, Y, and HREEs. Eventually, REEs, Y, Th, and U in the fluid combined with P to form monazite and xenotime, while the other elements partially precipitated with the crystallization of the FGZ-3 zircons. Although the alteration of biotite only released approximately 190 ppm of Sn into the fluid, this is still a significant Sn source for the Sn deposits surrounding the Mopanshan pluton, taking the granite size (∼50 km2) and the volume proportion of biotite (∼5%) into account. Furthermore, based on previous studies on tourmaline from the Mopanshan granite and regional geochemistry, it may be inferred that the addition of wall rock components may also play an important role in Sn mineralization.

Partitioning of tin between mafic minerals, Fe-Ti oxides and silicate melts: Implications for tin enrichment in magmatic processes

The partition coefficients of Sn (tin) between minerals and silicate melts (DSnmin/melt) are vital for understanding the Sn enrichment during magmatic processes related to tin-granites. However, experimentally determined DSnmin/melt values remain scarce due to the difficulty in avoiding severe Sn loss to noble metal capsules. In this study, we performed mineral/melt Sn partitioning experiments at 0.5–1.0 GPa, 850–1000 °C, and fO2 of FMQ + 8 to ∼ FMQ − 1. The fO2s were imposed by solid buffers of Ru–RuO2, Re–ReO2, Ni–NiO, Co–CoO and graphite using three improved capsule designs: 1) a single sample capsule (Pt) for the Ru–RuO2 buffered runs, 2) double capsules with Pt95Rh05 as outer capsule and Re as inner sample capsule for the graphite and Re–ReO2 buffered runs, and 3) triple capsules for the Co–CoO and Ni–NiO buffered runs, with Pt95Rh05 (or Au) as outer capsule, Re lined Pt as inner sample capsule. These new capsule designs avoided significant Sn loss and enabled us to obtain accurate DSnmin/melt at a controlled fO2. The experimental results show that DSnmin/melt values are 0.08–12.66 for amphibole, 0.01–5.55 for biotite, 0.09–10.39 for clinopyroxene, 0.004–0.97 for orthopyroxene, < 0.01 for olivine, 1.34–108.43 for Ti-magnetite, 0.04–4.17 for spinel and 0.10–0.64 for ilmenite. The large variation of DSn for each mineral was mainly ascribed to the effect of fO2, which results in an arresting decrease of DSn with decreasing fO2. Under the reducing conditions (fO2 < FMQ), Sn is highly incompatible (DSn < 0.1) in almost all the minerals. Modeling results indicate that partial melting at low fO2 conditions results in Sn enrichment in the derived magma, while subsequent high degree of fractional crystallization is also important for the Sn enrichment in the residual melt. The experimental and modeling results thus explain why major primary tin deposits are always related to reducing and highly fractionated granites.

Non-ferrous metal of the Bronze Age of Northern Kazakhstan: geochemical characteristics and ore base

The chemical composition of 29 copper and bronze artifacts from the sites of the Petrovka and Alakul Cultures located be-tween the Tobol and Ishim Rivers (the burial grounds of Bekteniz and Dzhangildy 5, and the sites of Novonikolskoye 1 and Semioz-ernoye 2; Northern Kazakhstan) were analysed using mass spectrometry with inductively coupled plasma and laser ablation. The sites are 14C dated to the interval between the 19th–17th centuries BC. In the examined sample, the leading metallurgical group with a slight prevalence in both Petrovka and Alakul metals was “pure” copper; the second part of the metal was represented by tin bronzes — low-alloyed (up to 8 wt.% Sn) in the Petrovka, and high-alloyed (Sn up to 21 wt.%) in the Alakul Culture. The statistical analysis of the main components of trace elements in the metal demonstrated a division into six main geochemical groups. Among these, tin bronzes with an uninterpretable copper component (10 specimens), “pure” copper of Ural origin with Fe-Co-Ni-As-Zn correlations (9 specimens), and “pure” copper with polymetallic Sn-Pb-As-Ag-Se specialization (10 copies), corresponding to the ores of copper deposits of the Kokshetau anticlinorium, can be identified. An overview of the tectonic structures of Northern Ka-zakhstan shows the nearby presence of several porphyry copper and skarn deposits with ancient mines (Imantau, Baksinskoye, Akkan-Burlukskoye, etc.), which likely served as sources of copper ore. Closely associated with these are Greisen and quartz-vein-greisen tin deposits, but there is no reliable information about their use in ancient times. According to the composition of tin alloys in the analysed metal, two main types can be distinguished: tin (without correlation with other impurity elements) when using pure cassiterite, and tin-lead (with increased concentrations and correlation of As, Au, Bi, etc.) when using cassiterite-sulfide ores. The data show the association of the Bronze Age sites of Northern Kazakhstan with the ore and raw materials base in this region, and the intensity of trade exchange of metallurgical products between the Ural and Kazakhstan centers of metal production.

Air-based sputtering deposition of TiN(O)/a-TiNxOy multilayer films for enhanced mechanical properties and corrosion resistance

Extensive research has explored multilayer films for their distinctive mechanical and functional properties. This study employs an air-based sputtering technique, using air as a reactive gas under low vacuum conditions, to produce TiN(O)/a-TiNxOy multilayer films. By alternately adjusting the air/Ar flow ratios, the multilayer films with various modulation periods were created. The crystalline TiN(O)/amorphous TiNxOy multilayered structure was confirmed via cross-sectional microscopy and electron energy loss spectroscopy images and mappings. Hardness (H) and elastic modulus (E) initially increased, peaked, and then decreased with the modulation period, reaching a maximum hardness of 31.2 GPa and an elastic modulus of 343 GPa. The enhancements may be attributed to internal compressive stress, interface strain effects, and the inhibition of dislocation propagation throughout the films. Higher H/E ratios (0.09–0.11) and H3/E2 ratios (0.23–0.28 GPa) suggest enhanced resistance to elastic and plastic deformation, surpassing those of single-layered TiN(O). This enhancement is primarily attributed to the hard/soft multilayer design. Potentiodynamic polarization tests revealed improved corrosion resistance with decreasing modulation period, reaching optimal values Ecorr at −0.089 V and Icorr at 0.272 μA/cm2. This improvement is mainly ascribed to the multilayer design, which inhibits direct corrosion through grain boundaries. This air-based sputtering technique offers a facile approach for producing complex multilayer films, promising enhanced mechanical properties and corrosion resistance of coatings for various applications.

Characteristics of tin-containing fluoride toothpastes related to erosive tooth wear protection

ObjectivesTo assess the effect of different tin-containing toothpastes on the control of erosive tooth wear in enamel and dentin. MethodsEnamel and dentin slabs were randomly distributed into 7 experimental groups (n = 10/substrate): C−: negative control (Artificial saliva); AmF (regular fluoridated toothpaste without tin); Sn-1 (SnF2/NaF); Sn-2 (SnF2/NaF/SnCl2); Sn-3 (SnCl2/NaF); Sn-4 (SnF2/SnCl2); Sn-5 (SnCl2/AmF/NaF/chitosan). Specimens were submitted to 5-day erosion-abrasion cycling. Surface loss (SL) was determined with an optical profilometer. Tin deposition on the tooth surfaces and some characteristics of the toothpastes (pH, potentially available F−, %weight of solid particles, and RDA) were also assessed. Data were statistically analyzed (α = 0.05). ResultsFor enamel, the Sn-2 presented the lowest SL, not differing significantly from AmF, C+, and Sn-3. The SL of these groups was significantly lower than the C−, except for Sn-3. Sn-1 and Sn-4 were also not significantly different from C−. For dentin, C− significantly showed the highest SL values, whilst, Sn-1 presented the lowest SL, not differing significantly from AmF, Sn-2, C+, and Sn-3. There was a significant positive association between enamel SL and the pH and tin deposition. Dentin SL was significantly negatively associated with the %weight of solid particles and RDA. ConclusionsMost of the tin-toothpastes were able to exhibit some protection against ETW. In this process, the toothpastes characteristics play a role, as lower enamel SL was significantly associated with lower pH values and tin deposition; and lower dentin SL was associated with higher %weight of solid particles and RDA of the toothpastes. Clinical significanceTin-containing toothpastes can be used for erosive tooth wear protection, but our study showed that their effect depends on the pH, amount of tin deposition, % weight of solid particles and RDA of the toohpastes.

Radioactive Mineral Distribution on Tin Placer Deposits of Southeast Asia Tin Belt Granite in Bangka Island

Bangka Island is an area rich in primary and secondary tin deposits. Tin deposits are formed around the contact between granite and older rocks, while secondary tin deposits are formed in the modern channels and paleochannels. Many previous researchers have researched radioactive minerals in primary tin deposits and modern channel deposits, but research on radioactive minerals in paleo channel deposits has never been carried out. The characterization of radioactive minerals in paleo channel deposits was done in this study to determine the potency of radioactive minerals in secondary tin deposits by comparing the content of radioactive minerals in paleochannels with modern channels and tin mine tailing deposits. The data used were mineralogical data and radioactivity data, along with the uranium and thorium content of the rocks from several previous studies. Data showed significant mineral content differences in paleo channel, modern channel, and tin mine tailings deposits. Mineral (monazite and zircon) content in tin mine tailing deposits was the highest. Source rocks for the radioactive minerals monazite and zircon are predicted to be the granitic rocks or tourmaline quartz veins of primary tin deposits. The radioactivity value of rocks in the paleo channel is relatively the same as the modern channel, ranging from 20 to 150 c/s. Uranium content in paleo channel is the same as modern channel deposits, ranging from 10 to 15 ppm eU. The thorium content of the rocks in the paleo channel ranges from 1 to 60 ppm eTh, while in the modern channel, it ranges from 1 to 45 ppm eTh. The radioactivity value and uranium content of the rocks are less effective for determining potential areas of radioactive minerals in placer tin deposits. In contrast, data on thorium content are quite effective for determining potential areas of radioactive minerals in placer tin deposits.

Discussion of the W-Sn-REE Metallogenic Background in the Nanling Region of South China: Evidence from Satellite Gravity and Magnetic Data

The Nanling region is located at the intersection of the Yangtze Block and Cathaysia Block and is characterized by complex geological and tectonic processes, as well as distinct W-Sn-REE mineralization. Despite extensive research on the mineralization of W-Sn and REE deposits in the Nanling region, the factors impacting the distribution pattern of eastern tungsten and western tin deposits, as well as the mechanism of REE enrichment in the parent rocks, remain uncertain. Deep structural and tectonic variability plays a crucial role in the formation of mineral deposits in the upper crust. Information on deep structural and tectonic variability is contained in the Moho depth, Curie depth, effective elastic thickness, lithospheric density, and thermal structure derived from the processing and inversion of satellite gravity and magnetic data. In this paper, we comprehensively analyse satellite gravity and magnetic data from the Nanling region, integrating the processing and inversion results with the tectonic evolution of this region and relevant geological information. It is hypothesized that the Chenzhou–Linwu fault serves as a channel for mineral and thermal transfer in the Sn ore aggregation zone, facilitating the material transport from the deep mantle to the surface and ultimately leading to the formation of Sn-enriched granite. The collection area of tungsten ore is more weakly associated with the Chenzhou–Linwu fault, and through deep heat transfer, tungsten components are primarily concentrated in the Earth’s crust to produce W-enriched granite. The primary source of REE enrichment in the parent rocks associated with REE mineralization is predominantly derived from the felsic crust, and the rapid intrusion of deep magma resulting from the subduction and retraction of the Palaeo-Pacific Plate is a contributing factor to the contrasting enrichment of light and heavy rare-earth elements. Mineral crystalline differentiation is relatively high, leading to the formation of ore-forming parent rocks with high heavy rare-earth element contents.

Room-temperature sputter deposition of gold-colored TiN assisted by niobium bombardment from a bipolar HiPIMS source

The deposition of gold-colored titanium nitride films without applying substrate heating is of significant interest due to the increasing demand for decorative coatings on temperature-sensitive three-dimensional substrates. Here, the energetic impact of Nb1+ ions during the deposition of TiN was achieved within a bipolar high-power impulse magnetron sputtering discharge operating on a Nb target. A separate titanium target was operated with direct current magnetron sputtering in the same reactive argon–nitrogen mixture. This process aimed to achieve a dense titanium nitride with the assistance of the niobium ion bombardment. The niobium controlled the phase formation and structure of the resulting Nb-containing TiN coating without needing external heating. The niobium ion bombardment during deposition increases the density of the titanium nitride coatings, promoting the formation of the cubic phase favored for its gold color and excellent mechanical and tribological properties, including HF1-level adhesion. Energy-selective mass spectrometer investigations revealed an increase in the flux and the energy of titanium ions due to momentum transfer from niobium ions to titanium neutrals in the plasma generated between the targets and the substrate. The approach introduced here paves the way for the formation of the cubic phase of Nb-doped TiN films without external heating, producing coatings with combined decorative and protective properties.

Electrochemistry of Tin Deposition from Methanesulfonic Acid

The electrolytic refining of crude tin is generally carried out in the fluorosilicic acid (H2SiF6) system with the assistance of bone glue and β-naphthol. However, the high saturated vapor pressure and low stability of H2SiF6 present environmental concerns and do not align with sustainable development goals. In this paper, the electrochemical behavior of tin on a glassy carbon (GC) electrode was studied in a relatively green and environmentally friendly methanesulfonic acid (MSA) system. Bone glue, sodium lignosulfonate, and β-naphthol were used as additives to make the deposit morphology smooth and to ensure grain refinement. The electrochemical reduction process of Sn2+ in an MSA system is a quasi-reversible process controlled by diffusion. The apparent activation energy Ea = 14.189 kJ/mol for the ion diffusion of Sn2+ was further calculated. The results of chronoamperometry showed that the electrocrystallization of Sn2+ on the GC electrode gradually tended to three-dimensional instantaneous nucleation with the increase in applied potential. The morphology and phase of the deposits were analyzed using scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results showed that the deposits were uniform and dense pure tin. This work elucidates the electrochemical behavior of tin in a methanesulfonic acid system.

Towards a Model-Based Interpretation of Measurements of Mineralogical and Chemical Compositions

We introduce a new methodology for inference of fluid composition from measurements of mineralogical or chemical compositions, expanding upon the use of reactive transport models to understand hydrothermal alteration processes. The reactive transport models are used to impute a latent variable explanatory mechanism in the formation of hydrothermal alteration zones and mineral deposits. An expectation maximisation algorithm is then employed to solve the joint problem of identifying alteration zones in the measured data and estimating the fluid composition, based on the fit between the mineral abundances in the measured and predicted alteration zones. Using the hydrothermal alteration of granite as a test case (greisenisation), a range of synthetic tests is presented to illustrate how the methodology enables objective inference of the mineralising fluid. For field data from the East Kemptville tin deposit in Nova Scotia, the technique generates inferences for the fluid composition which compare favourably with previous independent estimates, demonstrating the feasibility of the proposed calibration methodology.

First-principles study of F adsorption by TiN with its oxide surface in three-dimensional NAND flash memory

Three-dimensional (3D) NAND flash memory is a key technology in the field of mainstream memory solutions, which is primarily due to its extremely low bit cost. The architecture of 3D NAND, characterized by its vertically stacked design, substantially enhances the capacity of individual chips. This advancement is completely consistent with the demands for high-capacity data storage in contemporary environments, securing its widespread adoption in diverse application scenarios. As storage density increases, the complexity of process integration increases, bringing new challenges. The word lines in 3D NAND are typically filled by using gate replacement techniques, and compared with chemical vapor deposition (CVD), atomic layer deposition (ALD) is favored for its superior step-coverage, especially for depositing tungsten (W) at the gate. However, due to the complexity of the replacement gate deposition structure, fluorine (F) residues are found in the voids of the tungsten metal gate filling structure and diffuse into the surrounding structure under subsequent process conditions, corroding other films such as silicon oxide and degrading device performance and reliability. To alleviate the problem of fluorine attack, a thin layer of titanium nitride is usually deposited as a barrier layer before deposition of tungsten gate, which blocks the fluorine in the tungsten gate and prevents its diffusion into the oxide layer. Previously, there were studies to increase the ability to stop F diffusion by varying the thickness of the F blocking layer (TiN). However, increasing the thickness of TiN will further increase the complexity of high aspect ratio etching in the 3D NAND process, which will have adverse effect on subsequent processes. To further minimize the effect of fluorine erosion, residual fluorine elements can be removed by introducing annealing in the subsequent process flow. In the actual 3D NAND process, elemental fluorine (F) is adsorbed and accumulates on the TiN surface, and is further activated by subsequent high-temperature processes, leading to severe fluorine erosion. The delay between TiN deposition and subsequent processing steps is hypothesized to facilitate fluorine adsorption due to the oxidation of TiN. This work corroborates this hypothesis through first-principles calculations, and demonstrates the role of TiN oxidation in fluorine adsorption. In this work, we evaluate the effect of this oxidation on the fluorine-blocking effectiveness of the TiN barrier layer. We simulate the adsorption of fluorine-containing by-products on TiN and its oxides, providing theoretical insights into mitigating fluorine attack. The higher degree of oxidation of TiN is more likely to cause F adsorption, and Ti exposed surface TiN is more prone to oxidation, which is more likely to cause F adsorption in unoxidized condition and oxidized condition. Based on these insights, we implemente an ammonia purge treatment in 3D NAND manufacturing, which effectively minimizes fluorine attack, reducing the leakage probability of word line by 25% and wafer warpage by 43%.

Barium isotope variations in highly-fractionated granites linked to tin mineralization: New insights into tin recycling and enrichment in the continental crust

Most primary tin deposits are intimately associated with highly-fractionated granites (HFGs), but the factors controlling the formation of tin mineralization; including source enrichment, partial melting, fractional crystallization, and fluid processes, are still subject to debate. The potassium-rich Yanbei volcanic-intrusive complex is part of the world-class Nanling WSn metallogenic belt in South China and contains both barren and Sn-rich igneous rocks. We report here Ba isotope compositions of these rocks in an effort to elucidate the relationship between HFGs and related Sn mineralization. Overall, the results show δ138/134Ba values ranging widely from −0.83 to +0.21‰. The δ138/134Ba of the barren volcanic rocks (−0.11 to +0.21‰) are correlated with SiO2, Sr, and Ba contents, and Eu/Eu* values in a manner indicating that fractional crystallization is the main control over their Ba isotope variation. The most fractionated volcanic rocks have the highest δ138/134Ba due to crystallization of alkali-feldspar rich in light Ba isotopes. In contrast, the highly-fractionated tin granites have low Ba contents and δ138/134Ba values of −0.83 to −0.23‰. These low values cannot be explained by either addition of mantle-sourced melts and magmatic fluids, or fractional crystallization and fluid circulation at the shallow emplacement level. Rather, these geochemical features are likely inherited from an isotopically lighter crustal source with enhanced tin contents related to the recycling of intensely chemically weathered sediments. When combined with bulk-rock chemical data, the Ba isotope data suggest that assimilation of this tin-enriched source played a key role in forming the tin granites and related tin deposits.

Zircon and cassiterite U-Pb dating identifies the first Early Cretaceous Sn deposit in Fujian: Implication for tin mineralization potential in the southeastern coastal belt of South China

The Xiayi Sn deposit, located in the Sanming city, southeast China, is the largest Sn deposit in Fujian province. The mineralization mainly consists of cassiterite-bearing veinlets and stockworks, and it is spatially associated with the granodiorite porphyry. Despite its economic significance, few studies have been carried out, and the mineralization age remains unknown. In this paper, we present the first geochronological data on the cassiterite and the associated granodiorite porphyry, Hf isotope of the zircon, and trace element compositions of cassiterite from the Xiayi Sn deposit. These data give precise age of the Sn mineralization and constrain its relationship with the granitic intrusion. Zircon U-Pb dating of the ore-related granodiorite porphyry yielded the age of 138.3 ± 1.8 Ma, which agreed well with the cassiterite U-Pb age of 136.5 ± 1.4 Ma, documenting the genetic link between the Sn mineralization and granitic magmatism. Zircon εHf(t) ranged from −4.5 to −1.8 with a weighted mean of −3.4 and the Hf model ages (TDM2) vary from 1.31 to 1.47 Ga with a mean value of 1.40 Ga. These data indicate that the granodiorite porphyry originates from the partial melting of the crustal materials of Mesoproterozoic basement and show the addition of mantle-derived materials, similar to typical Sn mineralized granite in the southeastern coastal tin belt and Nanling tungsten-tin belt. Besides, cassiterite from Xiayi deposit show clear CL-bright and CL-dark sector zonation in the cathodoluminescence images. LA-ICP-MS trace element analyses of cassiterites indicate a high Ti and Fe but low Nb and Ta contents in both CL-bright and CL-dark sector zones, while the W content is significantly high in the CL-dark zone and low in the CL-bright zone. Cassiterite trace element compositions together with the mineralization pattern and alteration assemblages indicate that Xiayi is a porphyry tin deposit. These results provide proof of the extension of the southeastern coastal Sn metallogenic belt and offer potential breakthroughs in tin deposit exploration in southwestern Fujian Province.

Capitana mine, Tignamar district, a unique tin – bismuth concentration in the Chilean Central Andes, 250 km west of the Bolivian Tin Belt: Link to the Proterozoic-Paleozoic basement Belen inlier and the Arequipa-Antofalla terrane, a probable remnant of Laurentia

The Capitana mine, Tignamar District, is a unique Sn-Bi concentration in the highlands of Arica, in the Chilean Central Andes. Tin deposits associated with Triassic to Pliocene age igneous rocks are plentiful in the Tin Belt of Peru, Bolivia, and NW Argentina, but have not been reported in Chile, where contemporaneous rocks formed metallogenic belts rich in Fe, Cu, Mo, Ag and Au. We describe vein ore from Capitana mine, a small but exceptional Sn-bearing Pb-Bi-Ag-Cu-Sb-As epithermal deposit in the Tignamar (or Ticnamar) district in the high Andes of Arica, Chile, ca. 250 km west of the Bolivian Tin Belt. Fluid inclusions in vein quartz trapped a non-boiling, low salinity (<∼4 wt% NaCl equiv.), moderate T fluid (minimum T ∼ 220 °C) prior to metal precipitation. Flashing of this fluid, likely due to rapid changes in confining P, was synchronous with metal deposition; sulfosalt textures show evidence of syn-deformational growth. Although located within a district considered a porphyry copper system of Early Miocene age, it is likely that the Capitana deposit formed later, mainly as a result of regional hydrothermal activity related to compressive and transpressional tectonics as young as Pliocene. Common lead is 206Pb/204Pb 18.18; 207Pb/204Pb 15.61; and 208Pb/204Pb 38.53, significantly less radiogenic than that of Bolivian Sn deposits, and has a Paleozoic model lead age. These values point to affinities with a tectonically-emplaced inlier of crystalline basement of Proterozoic – Early Paleozoic age known as the Belen Metamorphic Complex, and with the Arequipa-Antofalla basement terrane, a probable remnant of Laurentia (North America), left behind during the dismemberment of the Rodinia Supercontinent. The complex mineralogy of Capitana vein, unlike other Chilean deposits, includes various sulphides and sulphosalts with Cu, Fe, Zn, Pb, Bi, Sn, Ag, As, Sb, Ga and In, and is exceptionally rich in U.

Indonesian National Tin Production Planning: Conceptual Framework

Tin mining in Indonesia has been regulated by Indonesia Law Number 3 of 2020. However, it has not been fully utilized in Indonesia despite the country's abundant tin deposit opportunities, its position as one of the significant producers of tin globally, and the impact on both the global tin stock and price. In light of this, a comprehensive literature review has been carried out; an initial conceptual framework and causal loop diagram of Indonesia’s national tin production planning have been produced to produce the concept of an instrument for setting national tin production quotas and the concept of formulating the distribution of national tin production levels that could be a reference for future researchers as well as Government of Indonesia in order to find the national tin production planning.

Isotopic metal compositions of Viking and medieval tin artifacts from Poland reveal expansive trade network

The lack of historically known tin deposits in Poland requires that the source of tin metal in ancient artifacts must be derived from foreign sources. To identify these external sources in the Viking Period, a combination of Pb and Sn isotope compositions and trace element analyses on a group of tin and tin rich alloys from three settlements in Poland was conducted. The integration of the chemical techniques reveals several sources for the tin rich artifacts, where group: 1) possesses Pb isotope values that overlap the Europe array which possess the highest (+1.6 ‰) and lowest (−1.1 ‰) Sn isotope values coupled with elevated In concentrations 2) has Pb isotope values that overlap the Slovakian array which possess lower Sn isotope values (+0.1 ‰ to + 0.3 ‰) coupled with low In and Te concentrations 3) has a Pb isotope value that is radiogenic which possesses a high Sn isotope value (+1.1 ‰). Group 1 artifacts are split into two sources designated by the higher Sn isotope values from Cornwall and the lower Sn isotope values from Brittany and are found in the two coastal settlements. Group two artifacts match a Slovakian origin, while one artifact labeled in group three possesses an Anatolian source. Defining the tin rich artifact sources allows constraint of the tin sources for the mixed alloys like bronze and pewter. In this instance the tin isotope values fall within two sources defined by the tin metal artifacts, Brittany and Cornwall. The chemical approach presented here defines distal metal sources to reveal a geographically expansive interconnected tin trade network that was predominantly European, in Viking times through chemical analysis of ornaments, coins, and beads.

Magmatic–Fluid System of the Vysokogorskoe Porphyry Tin Deposit (Sikhote-Alin, Kavalerovo Ore District, Primorsky Krai, Russia): a Magmatic Stage

Magmatic–Fluid System of the Vysokogorskoe Porphyry Tin Deposit (Sikhote-Alin, Kavalerovo Ore District, Primorsky Krai, Russia): a Magmatic Stage