265 Ma Research Articles

Primary Minerals and Age of The Hydrothermal Quartz Veins Containing U-Mo-(Pb, Bi, Te) Mineralization in the Majerská Valley near Čučma (Gemeric Unit, Spišsko-Gemerské Rudohorie Mts., Slovak Republic)

An occurrence of vein U-Mo mineralization is located in the Majerská valley near Čučma, about 7 km to the NNE of the district town of Rožňava (Eastern Slovakia). Mineralization is hosted in the acidic metapyroclastics of the Silurian Bystrý Potok Fm. (Gemeric Unit), and originated in the following stages: (I.) quartz I, fluorapatite I; (II.) quartz II, fluorapatite II, zircon, rutile chlorite, tourmaline; (III.) uraninite, molybdenite, U-Ti oxides; (IV.) pyrite I, ullmannite, gersdorffite, cobaltite; (Va.) galena, bismuth, tetradymite, joséite A and B, Bi3(TeS)2 mineral phase, (BiPb)(TeS) mineral phase, ikunolite; (Vb.) minerals of the kobellite–tintinaite series, cosalite; (VI.) pyrite II; (VII.) titanite, chlorite; and (VIII.) supergene mineral phases. The chemical in-situ electron-microprobe U-Pb dating of uraninite from a studied vein yielded an average age of around 265 Ma, corresponding to the Guadalupian Epoch of Permian; the obtained data corresponds with the age of Gemeric S-type granites. The age correlation of uraninite with the Gemeric S-type granites and the spatial connection of the studied mineralization with the Čučma granite allows us to assume that it is a Hercynian, granite-related (perigranitic) mineralization.

Cu-Ni mineralization in Early Permian mafic complexes in the Kalatage area of eastern Tianshan (NW China): Petrogenetic constraints from geochronology, geochemistry, and Hf-Sr-Nd-Os isotopes

The Early Permian was a critical period in the long history of accretion and collision of the southern Altaid orogen. Early Permian mafic-(ultramafic) intrusions and mafic–ultramafic-related sulfide Cu-Ni deposits are common in the eastern Tianshan, but the sulfide Cu-Ni deposits related to the mafic intrusions are still poorly studied, and yet provide key information on the ambient tectonic evolution. In order to help understand their petrogenesis, we report new data on the Early Permian mafic intrusions and related sulfide Cu-Ni deposits in the Dananhu arc of the eastern Tianshan in NW China. The ore-bearing Yueyawan complex is a well-differentiated, zoned mafic intrusion consisting of troctolite, olivine gabbro, layered gabbro, gabbro, and leucogabbro from the bottom upwards. The ore bodies are primarily strata-bound within olivine gabbros and troctolites at the bottom of the complex. The ores are more enriched in Cu than Ni than the more enriched, disseminated, veined and massive equivalents. Gabbros from the mafic complex yield zircon crystallization ages that range from 265 Ma to 273 Ma. The gabbros are tholeiitic and characterized by typical subduction-related geochemical signatures with low TiO2 contents, enrichments in Rb, Ba, U, K, Pb, and Sr, depletion in Nb and Ta, positive Eu and Ti anomalies, high εNd(t) values of +7.44 to +8.06, zircon εHf(t) values of +11.68 to +20.58, and low (87Sr/86Sr)i (0.703322–0.703416). The gabbroic rocks have positive correlations between SiO2 and TiO2, Al2O3, CaO, Nb, and Y, and negative correlations between SiO2 and MgO, Ni, and Co. The (187Os/188Os)i and γOs values of sulfides from the Yueyawan complex that contains Cu-Ni deposits range from 0.266 to 0.372 and 112 to 197, respectively. These geological, petrological, and geochemical characters indicate that the gabbros were mantle-derived, and that fractionation and crustal contamination were essential for the genesis of the magmatic Cu-Ni sulfide deposits. After integrating our data with those of previous investigations, we conclude that the protoliths of the sulfide deposits were probably derived from an asthenospheric garnet-free mantle in a subduction setting in the Early Permian. Oblique ocean-ridge subduction and a resultant slab window plausibly induced asthenospheric upwelling that gave rise to the generation of the mantle-derived melts, which likely moved into strike-slip faults through a slab window in the supra-subduction zone. Strong fractionation, crustal contamination, and multi-stage eruptions led to formation of the Cu-Ni sulfide deposits.

Electrophoretic deposition of metal-organic framework derived porous copper oxide anode for lithium and sodium ion rechargeable cells

This article demonstrates the applicability of electrophoretically fabricated CuO-carbon black (CB) film as negative electrodes for lithium and sodium-ion rechargeable cells. CuO powder is derived from a thermally decomposed copper metal-organic framework (MOF) template. Electrophoretic deposition (EPD) of CuO-CB electrode has been carried out from a stable CuO-CB suspension, which is prepared in isopropanol medium containing polyacrylic acid and nickel nitrate as dispersant and charging agent respectively. The obtained EPD films are found to be porous and strongly adherent to underlying current collector, with a uniform distribution of CB and CuO. These films are observed to retain a reversible specific capacity of 500 mA h g−1 at 0.5 A g−1 and 256 mA h g−1 at 0.1 A g−1 after 100 cycles as Li-ion battery and Na-ion battery anode respectively. The uniformly dispersed CuO within the conductive network of CB particles is found to sustain the high-rate battery operations efficiently and exhibit a specific capacity of 265 mA h g−1 at 5 A g−1 (LIB) and 140 mA h g−1 at 3 A g−1 (SIB). Owing to the simple and cost-effective route for fabricating these negative electrodes, electrophoretically deposited CuO-CB porous film proves to be a suitable candidate for high-rate Li-ion and Na-ion batteries.

The Evolution of Calcification in Reef-Building Corals.

Corals build the structural foundation of coral reefs, one of the most diverse and productive ecosystems on our planet. Although the process of coral calcification that allows corals to build these immense structures has been extensively investigated, we still know little about the evolutionary processes that allowed the soft-bodied ancestor of corals to become the ecosystem builders they are today. Using a combination of phylogenomics, proteomics, and immunohistochemistry, we show that scleractinian corals likely acquired the ability to calcify sometime between ∼308 and ∼265 Ma through a combination of lineage-specific gene duplications and the co-option of existing genes to the calcification process. Our results suggest that coral calcification did not require extensive evolutionary changes, but rather few coral-specific gene duplications and a series of small, gradual optimizations of ancestral proteins and their co-option to the calcification process.

Permian lamprophyres from the Western Carpathians: a review

Abstract Calc-alkaline lamprophyres from the Western Carpathians occur as dykes and sills in the crystalline complexes (predominantly granites and gneisses) of the Tatric Unit. Some of the lamprophyre dykes have been strongly overprinted by tectonism and hydrothermal fluid ingress. They have a similar mineralogical composition, and they are comprised of clinopyroxene, amphibole, biotite and plagioclase. Based on their modal composition, they can be classified as spessartites and kersantites, and based on their geochemical composition, most of them are of calc-alkali type. Lamprophyres from individual core complexes (e.g. the Malá Fatra Mountains and Nízke Tatry Mountains) exhibit variable Nb, Ta and Sr–Nd isotope signatures. These differences are probably due to compositional variations in the mantle source and/or the lower crust at the site of lamprophyre melt generation, or variable incorporation of crustal material. The age of the lamprophyres is Permian ( c. 265 Ma) based on U–Pb LA-ICP-MS dating of apatite micro-phenocrysts.

Evidence for widespread mid-Permian magmatic activity related to rifting following the Variscan orogeny (Western Carpathians)

The Gemeric and Veporic Superunits of the Western Carpathians correlate to the Lower and Middle Austroalpine tectonic units (nappes) of the Eastern Alps. The Gemeric Superunit is characterized by small exposures of rare-metal granites, and their ages impact understanding its tectonic history and how this portion of the Carpathians relates to other Permian age granites exposed throughout Europe and the Western Mediterranean. Here we present new Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) and Secondary Ion Mass Spectrometry (SIMS) zircon U--Pb ages from northern (Hnilec) and southern Gemeric granite exposures (Betliar, Elisabeth Mine, Poproč) and one from the Veporic Superunit (Klenovec). Geochemical analyses of Betliar and Klenovec samples indicate they are highly differentiated and fractionated from a clay-rich source, consistent with published reports for these granites. Zircon saturation temperatures average 733 ± 27 °C (Betliar) and 756 ± 61 °C (Klenovec). Most Gemeric granitic zircons are Permian (n = 231 spots), with some inherited zircons giving Middle Ordovician to Late Silurian (n = 26), and some Triassic (n = 6) U--Pb ages. The dominant Permian U--Pb yield crystallization ages of at 264 Ma for the Gemeric granite and 265 Ma for the Veporic Superunit's Klenovec granite (n = 26). Klenovec zircons typically show distinct yellow rims in cathodoluminescence, characteristic of lower temperature overprint (<600 °C). These granite zircon ages overlap those from the radiolarite-bearing metasediments from the Meliata Ocean exposed in the Dobšiná region (263.9 ± 2.7 Ma, LA-ICP-MS, ±1σ). The detrital zircon U--Pb ages thus imply a possible beginning of sedimentation in the Meliata Ocean as early as the mid-Permian. The genesis of the Gemeric and the Klenovec granites is related to post-collisional extension. These data link the Western Carpathians to a regional widespread occurrence of Permian magmatism in the European Variscan and Western Mediterranean realms, consistent with regional magmatic re-equilibration of the Moho. This scenario likely occurred in response to a thermal surge that involved significant decompression and extension, lower crustal melting, upward displacement of the Moho, and delamination of the mantle-lithosphere that contributed substantially towards Variscan crustal thinning.

RF Transceiver for the Multi-Mode Radar Applications.

In this work, a multi-mode radar transceiver supporting pulse, FMCW and CW modes was designed as an integrated circuit. The radars mainly detect the targets move by using the Doppler frequency which is significantly affected by flicker noise of the receiver from several Hz to several kHz. Due to this flicker noise, the long-range detection performance of the radars is greatly reduced, and the accuracy of range to the target and velocity is also deteriorated. Therefore, we propose a transmitter that suppresses LO leakage in consideration of long-range detection, target distance, velocity, and noise figure. We also propose a receiver structure that suppresses DC offset due to image signal and LO leakage. The design was conducted with TSMC 65 nm CMOS process, and the designed and fabricated circuit consumes a current of 265 mA at 1.2 V supply voltage. The proposed transmitter confirms the LO leakage suppression of 37 dB at 24 GHz. The proposed receiver improves the noise figure by about 20 dB at 100 Hz by applying a double conversion architecture and an image rejection, and it illustrates a DC rejection of 30 dB. Afterwards, the operation of the pulse, FMCW, and CW modes of the designed radar in integrated circuit was confirmed through experiment using a test PCB.

Detrital-zircon U–Pb geochronology of Jurassic sandstones in North China Craton (Daqingshan area, China): new constraints on provenance and tectonic implications

The Daqingshan area in China located in the center part of the Khondalite belt, north of the Ordos Block and south of the Yinshan Block. The Daqingshan basin is the best-preserved Mesozoic basin that is oriented nearly east-west. Previous studies suggest that the provenance of Jurassic sediment is mainly the Khondalite belt and no material from Yinshan Block. We present detailed data on the detrital-zircon geochronology of the Jurassic sandstones from the Daqingshan area. The detrital-zircon U–Pb age data of the Wudanggou and Changhangou Formations show two peaks at ~2450 Ma and 1970–1930 Ma, with a few of Archean ages. The detrital-zircon age data of the Daqingshan Formation show three distinctive age populations of 2560–2460 Ma, 1950–1750 Ma, and 320–265 Ma. Comparison with the age of the surrounding magmatic rocks suggests that the main source area is the Wulashan–Daqingshan Complex, with the Yinshan Block being a lesser source. However, more Archean and Paleozoic detrital zircon occurs in the Daqingshan Formation, probably as a result of the rise of the western part of the basin and eastward movement of the center of the basin, thereby increasing provenance from the Yinshan Block. The Yanshan movement caused massive amounts of Yinshan material to move southward during the Middle-Late Jurassic. However, the barrier of the Yinshan Mountains caused Yinshan material to be deposited mainly in the eastern part of the basin.

Geochronology and petrogenesis of Carboniferous and Triassic volcanic rocks in NW Laos: Implications for the tectonic evolution of the Loei Fold Belt

The Loei Fold Belt is one of the most significant tectonic and metallogenic belts in the Indochina Block. However, origin and tectonic significance of volcanic rocks in several volcanic belts of this fold belt remain ambiguous. In this paper, we present new petrochemical data, zircon U-Pb ages and Lu-Hf isotopic data for volcanic rocks from the Loei Fold Belt in northwestern Laos. The basaltic and andesitic tuffaceous rocks have Late Carboniferous zircon U-Pb ages (304 ± 2.1 Ma and 299 ± 1.8 Ma respectively), and display both MORB-like and arc-like geochemical signatures. Zircon Lu-Hf isotopic analyses give highly positive εHf(t) values of 8.99–14.24, indicative of a metasomatic mantle source which formed in a back-arc basin environment. On the other hand, the andesite and rhyolite samples have zircon U-Pb ages ranging from 236 Ma to 224 Ma, erupted during the Late Triassic, and formed in a continental margin arc setting (e.g., enrichment of LREE, depletion in Nb-Ta, Sr, and positive εHf(t) values of 9.87–12.25). With a synthesis of available geochronological, petrochemical and isotopic data, magmatic events in the Loei Fold Belt occurred in four periods: Ordovician-Silurian (450–400 Ma), Late Devonian-Middle Permian (ca. 361–265 Ma), Early-Middle Triassic (250–237 Ma) and Late Triassic (ca. 236–200 Ma), with peaks in Triassic and Carboniferous. Accordingly, we propose a tectonic-magmatic evolution model for the Loei Fold Belt. The Luang Prabang-Loei belt was a spreading back-arc basin during the Late Devonian-Middle Permian, and connected with the Nan back-arc basin. The basin expanded to its largest extent in the Permian period and started subduction in the earliest Triassic; the successive subduction did not terminate until the Late Triassic.

Middle–Late Permian magnetostratigraphy and the onset of the Illawarra Reversals in the northeastern Parana Basin, South America

SUMMARYRecent compilations of the Illawarra Reversals show remarkable differences in the onset age (265 Ma versus 269 Ma) and the magnetic polarity pattern, hampering the establishment of a reference geomagnetic timescale for the Middle–Late Permian. The Parana Basin hosts a 7-km-thick, discontinuous sedimentary succession spanning the Palaeozoic to the Mesozoic, including the Gondwana 1 supersequence which extends from Late Carboniferous to the Triassic or Jurassic. We provide the magnetostratigraphy of the middle and upper Permian part of this sequence of a ca. 300-m-long core, pertaining to the Passa Dois Group and the Piramboia Formation. Sample demagnetization of NRM revealed two magnetic overprints ascribed to the Brunhes chron and to the emplacement of Parana Large Igneous Province in the Early Cretaceous, respectively. Stable, dual polarity characteristic components (ChRM) were isolated at temperatures higher than 450 °C and interpreted as a primary detrital magnetic remanence (DRM), acquired during or soon after sediment deposition. Available U-Pb dating on volcanic zircons from the literature provided independent chronologic constraints for our magnetostratigraphy. A total of 8 reverse polarity intervals were identified, the lowermost of which (up to 110 m thick) correlates to the Kiaman Superchron. The overlying Illawarra is dominated by a reverse polarity magnetization with thin (4–5 m thick) normal polarity intervals. This pattern agrees with the Illawarra sequence from the Karoo Basin and other proposed timescales for the Permian. The onset of the Illawarra reversals is interpolated to ca. 270 Ma, close to the age of 269 Ma from the Karoo Basin. Combined magnetostratigraphy and geochronology yielded sediment accumulation rates of ca. 8 m Myr–1 for the Passa Dois Group in the northeastern (marginal) sector of the Parana Basin, indicating that Serra Alta and Teresina Formations span 279–274 Ma and 274–254 Ma, respectively.

SHRIMP U-Pb dating of detrital zircons from the Permian sandstones along the southern and northern margins of Xar Moron River, central inner Mogolia: Implications for provenance and the tectonic evolution of the eastern segment of the Central Asian Orogenic Belt

The Xar Moron River fault zone, located in the eastern segment of the Central Asian Orogenic Belt (CAOB), represents the intensely debated final collision zone of the Siberian Craton (SC) and North China Craton (NCC). To determine the tectonic evolution of the eastern segment of the CAOB, we undertook petrography and zircon U-Pb dating of the Huanggangliang and Linxi formations in the Wufendi and Xingfuzhilu areas along the Xar Moron River. Petrographic analysis of Permian sandstones revealed a close relationship between the sedimentary and orogenic sources suggesting short transport distances. A sample from the Huanggangliang Formation yielded detrital zircon U-Pb ages ranging from 2653 Ma to 265 Ma, with three age populations: at 2653 to 2443 Ma, 1935 to 1764 Ma, and 482 to 265 Ma, whereas samples from the Linxi Formation yielded detrital zircon U-Pb ages ranging from 3363 Ma to 257 Ma, with four age populations: at 2705 to 2403 Ma, 2011 to 1203 Ma, 571 to 375 Ma, and 356 to 257 Ma. The age spectrum differences of sandstones on both banks indicate that the Xar Moron River fault zone is the final collision zone of the eastern segment of the CAOB. The sandstone of Huanggangliang Formation yielded a weighted mean age of 265.7 ± 1.5 Ma, suggesting that the main deposition of the Huanggangliang Formation was during the Middle Permian. In addition, a comparison of the youngest age in the sedimentary rocks with U-Pb ages obtained for pyroclastic rock implies that the Linxi Formation formed in the late Permian. The results of our study support the view that the final closure of the eastern segment of Paleo-Asian Ocean (PAO) occurred during late Permian to earliest Triassic times.

Petrogenesis and tectonic implication of the Permian-Triassic syenogranites from the eastern segment of the East Kunlun Orogen, China

Permian-Triassic granitoids are widespread in the East Kunlun Orogen (EKO) and are influential in the re-construction of Paleo-Tethyan tectono-magmatic activities. In this contribution, zircon U–Pb dating and Lu–Hf isotopic as well as whole rock major and trace elements analysis have been conducted on a series of syenogranite plutons from the eastern segment of the EKO to constrain their petrogenesis and tectonic implication. The syenogranites are characterized by dominant mineral assemblages of K-feldspars and minor plagioclase and biotite, in contrast to the coexisting granodiorites that are rich in amphibole and plagioclase. Zircon U–Pb dating reveals that the studied syenogranites represent a two-stage magmatism from Middle Permian to Late Triassic (ca. 265 Ma and 235–232 Ma). Geochemical and mineralogical evidences show that the syenogranites are classified as high-K calc-alkaline, weakly peraluminous, highly fractionated (DI = 93–95) and moderately fractionated (DI = 82–91) I-type granites. They yield negative ɛHf (t) values (−13.25 to −0.11), which, together with their high Th/Nb (0.73–4.88), Th/La (0.29–2.65) and La/Nb (1.07–4.48) ratios and moderate pressure conditions (7–10 kbar) imply magma generation through partial melting of the normal-thickened lower crust. The magma underwent extensive plagioclase and subordinate K-feldspar fractionation during evolution. Given the old two-stage Hf model ages (TDM2 = 1270–2100 Ma), we interpret the ancient lower crust as their dominant source rocks with limited contribution from the juvenile lower crust. Our new data, in tandem with published data show that the Middle-Permian (ca. 265 Ma) Jialuhe syenogranites were formed during a period of local extension concomitant with the northward subduction of the Paleo-Tethyan ocean. In contrast, the Late-Triassic Qingshuihe (235 Ma), Keri (234 Ma), Wutuo (232 Ma) and Balong syenogranite plutons were generated in response to asthenospheric upwelling, lower crust delamination and subsequent continental rifting in a post-collisional extension stage along the convergent plate margins.

Early–Middle Permian plutons in the Langshan area, western Inner Mongolia, China, and their tectonic implications

Whether the southward subduction of the Paleo-Asian Ocean (PAO) beneath the northern North China Craton (NCC) was still on-going during Permian is a key issue for understanding the tectonic evolution of the southeastern Central Asian Orogenic Belt (Xing'an–Mongolia Orogenic Belt), and the voluminous Permian plutons distributed along the northern margin of the NCC can provide important insights into this controversy. New LA-ICP-MS zircon U–Pb ages from 4 basic, 6 intermediate and 11 acidic plutons in the Langshan area in northwestern NCC indicate that the plutons were formed during the Early–Middle Permian (290–265 Ma). Four basic diorites show affinities with continental basalts and probably crystallized from mantle-derived melts, whereas the intermediate and most acidic plutons are calc-alkaline I-type granitoids and four acidic plutons have the features of aluminous A2-type granites, and all of them probably originated from partial melting of various crustal materials. The Early–Middle Permian plutons and coeval bimodal volcanic rocks and continental basaltic intrusions occur together in both the northern NCC and adjacent Xing'an–Mongolia Orogenic Belt, implying a uniform extensional setting at that time. In addition to the intense magmatism, the regional extension also resulted in the development of a Red Sea-like limited oceanic basin within the Xing'an–Mongolia Orogenic Belt, and its subsequent closure may have created the Solonker suture. Such a tectonic scenario is in agreement with the Late Permian–Early Triassic blueschist-facies metamorphism induced by warm subduction of young oceanic slabs, Permian stratigraphic and paleontological data, and paleomagnetic record.

Genesis of the volcanic-related Be-U-Mo Baiyanghe deposit, West Junggar (NW China), constrained by mineralogical, trace element and U-Pb isotope signatures of the primary U mineralisation

The Volcanic-related Be-U-Mo Baiyanghe deposit is located in the Paleozoic Xuemisitan Volcanic Belt in West Junggar (NW China). It is the largest Be deposit in Asia which is dominantly hosted in late Devonian rhyolitic tuff and in the late Carboniferous Yangzhuang granite (313 ± 2 Ma) that were emplaced after the closure of the Junggar oceanic domain. The late Devonian rhyolitic tuff is a strongly fractionated peralkaline A1-type volcanic rock with a major magmatic enrichment in Nb, Y, Th, Be, Ta and U. Highly fractionated REE patterns and significant concentrations of Pb, Nb, Zr, Y, Th and Ta in the primary U mineralisation identified these tuffs as the dominant U and probably Be source for Be-U ore genesis in West Junggar. The primary high U concentrations (6.5 < Umean < 15.0 ppm) were released through volcanic glass devitrification and mobilised by oxidising fluids for the formation of hydrothermal mineralisation. The Yangzhuang granite is to the contrary a moderately fractionated moderate- to high-K calc-alkaline A2-type granite characterised by low magmatic U and Be enrichment (Umean = 2.9 ppm; Bemean = 4.7 ppm), and thus constituted a minor U source for the mineralisation as demonstrated by U release and remobilisation from metamict U-bearing accessory minerals.In the Baiyanghe deposit, structurally-controlled primary U mineralisation was temporally constrained by an in situ U-Pb isotopic minimum crystallisation age of 240 ± 7 Ma on pitchblende. This event represents the hydrothermal stage of U mineralisation that occurred during the early Permian–middle Triassic post-accretion event in West Junggar and paragenetically postdates the Be ore stage (ca. 303–265 Ma). The hydrothermal U mineralisation is mainly characterised by Pb-Nb-Ti-Zr-Mo-rich pitchblende veins associated with calcite and quartz, which crosscut Be-stage fluorite veins. During this episode of crustal extension, the Be-U-Mo ore therefore formed in a two-stage hydrothermal model within the same mineralising event: (i) oxidising meteoric and possibly basinal waters percolated downward into the basement through structures and mixed with CO2-bearing magmatic fluids derived from early generations of mafic dykes that intruded the host rocks in the Baiyanghe area. During the circulation of these thermal solutions along faults and fractured zones, Be was leached mainly from the Devonian rhyolitic tuff during hydrothermal alteration and dominantly transported as fluoride complexes in the fluids. These low-temperature (130–150 °C) ore solutions then reacted with Ca-rich minerals of the host rocks, which resulted in a pH increase that triggered fluorite precipitation in turn promoting Be deposition as bertrandite; and (ii) in a second stage, additional oxidising surface-derived fluids including meteoric waters and possibly basinal brines infiltrated the basement. U was also leached mainly from the late Devonian rhyolitic tuff and likely transported as chlorine and/or uranyl carbonate complexes in the fluids. U precipitated as pitchblende due to fO2 decrease when these low-temperature (120–125 °C) oxidising U-bearing solutions encountered favourable reducing environments mainly represented by dolerite and diabase dykes crosscutting the host rocks and/or carbonaceous shales at the contact with the Devonian rhyolitic tuff. Pitchblende then locally experienced dyke-emplacement related post-ore hydrothermal potassic alteration characterised by abundant illite crystallisation, significant Si gain and in situ relative enrichment of Nb, Ti, Th, and Ta due to strong U and Pb depletion. The primary U mineralisation was then largely oxidised into uranophane due to supergene alteration related to further meteoric water infiltration during late Mesozoic–Cenozoic crustal extension in West Junggar.The characteristics of the volcanic-related hydrothermal Be-U mineralisation in the Baiyanghe deposit show key similarities with Streltsovka (U-Mo-F) and Spor Mountain (Be-U) world-class districts, although Baiyanghe has much smaller resources than the ones in Streltsovka.

Tectonic and magmatic evolution of the Aqishan-Yamansu belt: A Paleozoic arc-related basin in the Eastern Tianshan (NW China)

Abstract The Aqishan-Yamansu belt in the Chinese Eastern Tianshan represents a Paleozoic arc-related basin generally accompanied by accretionary magmatism and Fe-Cu mineralization. To characterize the tectonic evolution of such an arc-related basin and related magmatism and metallogenesis, we present a systematic study of the geochronology, whole-rock geochemistry, and Sr-Nd isotopes of igneous rocks from the belt. New zircon U-Pb ages, in combination with published data, reveal three phases of igneous activity in the Aqishan-Yamansu belt: early Carboniferous felsic igneous rocks (ca. 350–330 Ma), late Carboniferous intermediate to felsic igneous rocks (ca. 320–305 Ma), and Permian quartz diorite and diorite porphyry dikes (ca. 280–265 Ma). The early Carboniferous felsic rocks are enriched in large ion lithophile elements (LILEs) and depleted in Nb, Ta, and Ti, showing arc-related magma affinities. Their positive εNd(t) values (3.3–5.9) and corresponding depleted mantle model ages (TDM) of 0.83–0.61 Ga, as well as high MgO contents, Mg# values, and Nb/Ta ratios, suggest that they were derived from lower crust with involvement of mantle-derived magmas. The late Carboniferous intermediate igneous rocks show calc-alkaline affinities, exhibiting LILE enrichment and high field strength element (HFSE) depletion, with negative Nb and Ta anomalies. They have high MgO contents and Mg# values with positive εNd(t) values (3.9–7.9), and high Ba/La and Th/Yb ratios, implying a depleted mantle source metasomatized by slab-derived fluids and sediment or sediment-derived melts. The late Carboniferous felsic igneous rocks are metaluminous to peraluminous with characteristics of medium-K calc-alkaline I-type granites. Given the positive εNd(t) values (6.3–6.6) and TDM ages (0.56–0.53 Ga), we suggest the late Carboniferous felsic igneous rocks were produced by partial melting of a juvenile lower crust. The Permian dikes show characteristics of adakite rocks. They have relatively high MgO contents and Mg# values, and positive εNd(t) values (7.2–8.5), which suggest an origin from partial melting of a residual basaltic oceanic crust. We propose that the Aqishan-Yamansu belt was an extensional arc–related basin from ca. 350 to 330 Ma; this was followed by a relatively stable carbonate formation stage at ca. 330–320 Ma, when the Kangguer oceanic slab subducted beneath the Central Tianshan block. As the subduction continued, the Aqishan-Yamansu basin closed due to slab breakoff and rebound during ca. 320–305 Ma, which resulted in basin inversion and the emplacement of granitoids with contemporary Fe-Cu mineralization. During the Permian, the Aqishan-Yamansu belt was in postcollision extension stage, with Permian adakitic dikes formed by partial melting of a residual oceanic crust.

Potentiodynamics of the Zinc and Proton Storage in Disordered Sodium Vanadate for Aqueous Zn-Ion Batteries.

A rechargeable Zn-ion battery is a promising aqueous system, where coinsertion of Zn2+ and H+ could address the obstacles of the sluggish ionic transport in cathode materials imposed by multivalent battery chemistry. However, there is a lack of fundamental understanding of this dual-ion transport, especially the potentiodynamics of the storage process. Here, a quantitative analysis of Zn2+ and H+ transport in a disordered sodium vanadate (NaV3O8) cathode material has been reported. Collectively, synchrotron X-ray analysis shows that both Zn2+ and H+ storages follow an intercalation storage mechanism in NaV3O8 and proceed in a sequential manner, where intercalations of 0.26 Zn2+ followed by 0.24 H+ per vanadium atom occur during discharging, while reverse dynamics happens during charging. Such a unique and synergistic dual-ion sequential storage favors a high capacity (265 mA h g-1) and an energy density (221 W h kg-1) based on the NaV3O8 cathode and a great cycling life (a capacity retention of 78% after 2000 cycles) in Zn/NaV3O8 full cells.

Multiple intrusion stages and mantle sources of the Paleozoic Kuznetsk Alatau alkaline province, Southern Siberia: geochemistry and Permian U–Pb, Sm–Nd ages in the Goryachegorsk ijolite-foyaite intrusion

ABSTRACT In this work, we present new U–Pb, Sm–Nd geochronology, major and trace‐element and isotopic composition (Nd, Sr, Pb, O) for the Goryachegorsk alkaline-mafic igneous rocks from the Kuznetsk Alatau (Siberia, Russian Federation). The age obtained using U-Pb in zircon, ~ 265 Ma, is considered to represent the crystallization age of Goryachegorsk intrusion in Late Permian times. LILE and HFSE composition, and isotope signatures indicate the heterogeneity of magmatic sources and the mixing of IAB- and OIB- like magmas. We interpret that this intrusion is characterized by the superposition of PREMA + EM 2 mantle plume magmas and other magmas derived from the melting of accretion-collision complexes from the Paleo Asian ocean margin. Mixing of mantle sources and continental crust resulted in variations of Nd-isotope composition (εNd (t) ~ 1.7–6.8) and lead isotope composition (206Pb/204Pb in 19.29, 207Pb/204Pb in 15.58, 208Pb/204Pb in 37.74), as well as an increase of 87Sr/86Sr (t) ~ 0.7049–0.7068 and δ18О 8.5–9.6 ‰, SMOW in igneous rocks. Additional geochronological data on the Kuznetsk Alatau alkaline mafic province suggest its origin at different times during the Paleozoic: at the Cambrian-Ordovician boundary (~ 510–480 Ma); Early-Middle Devonian (~ 410–385 Ma); and Late Permian (~ 266–262 Ma). Geochemical similarity between the regional alkaline magmatism emplaced at different ages provides insights into periodic mantle plume – lithosphere interaction over a time span of ca. 250 Ma.

Constructing non-hierarchical heterostructure Fe2O3/Fe2F5 porous spheres via precursor self-adsorbed fluoride ions for enhanced lithium- ion storage

Transition metal oxides have been considered as the next lithium-ion batteries (LIBs) anode materials because of their ultrahigh specific capacity, tunable redox reaction, high stability, and low cost. However, their shortcomings of inherent large volume expansion (except titanium dioxide and vanadium pentoxide), low conductivity, and poor reaction kinetics seriously hinder the practical applications in LIBs. To overcome these problems, non-hierarchical heterostructure Fe2O3/Fe2F5 porous spheres (NHFs) are designed and successfully prepared by the simultaneously adsorption of fluoride ions during the formation of the precursor with a facile one-pot self-assembly approach. Compared with traditional counterparts, the NHF exhibits high structural stability and improved reaction dynamics upon repeated electrochemical lithiation/delithiation. Furthermore, NHF exhibits an outstanding reversible capacity of 765 mA h g−1 at the current density of 0.2 A g−1, an excellent rate capability of 265 mA h g−1 at 10 A g−1, and an eminent cyclability with a capacity retention of 87.4% after 3000 cycles.

New Middle–Late Permian Paleomagnetic and Geochronological Results From Inner Mongolia and their Paleogeographic Implications

AbstractA combined paleomagnetic and geochronological study was conducted on the red beds of the Zhesi Formation (ZSF) in the Xilinhot–Songliao Block (XSB) and the andesites and sandstones of the Qingfengshan Formation (QFF) in the North China Block (NCB). The ZSF tuffs and the QFF andesites were dated to 265.3 ± 1.8 Ma and 254.8–257.1 Ma, respectively, using the zircon U–Pb laser ablation inductively coupled plasma mass spectrometry (LA–ICP–MS) method. A total of 246 paleomagnetic samples were subjected to stepwise thermal demagnetization. After removal of the low‐temperature viscous components acquired in the recent geomagnetic field, stable high‐temperature components (HTCs) were isolated from most samples. The HTC of the ZSF passed a fold test, and the HTC of the QFF passed both fold and reversal tests, indicating their primary origins. The corresponding paleomagnetic poles are 57.4°N/342.0°E (A95 = 4.3°) for the XSB at ~265 Ma and 54.3°N/20.2°E (A95 = 3.3°) for the NCB at ~255 Ma. Comparison of high‐quality Permian paleomagnetic poles of the XSB and NCB reveals a latitudinal convergence and relative rotation between them that led to a scissors‐like closure of the Solonker Ocean from west to east between ~265 and ~246 Ma, which controlled the mixing of the Cathaysian and Angara floras in space and time. The XSB and NCB moved rapidly northward between ~265 and ~255 Ma, which probably accelerated the end‐Guadalupian mass extinction in East Asia.

Geological Characteristics and Metallogenic Setting of Representative Magmatic Cu‐Ni Deposits in the Tianshan‐Xingmeng Orogenic Belt, Central Asia

A great number of magmatic Cu‐Ni deposits (including Kalatongke in Xinjiang and Hongqiling in Jilin) are distributed over a distance of almost 3000 km across the Tianshan‐Xingmeng Orogenic Belt, from Tianshan Mountains in Xinjiang in the west, to Jilin in eastern China in the east. These deposits were formed during a range of magmatic episodes from the Devonian to the Triassic. Significant magmatic Cu‐Ni‐Co‐PGE deposits were formed from the Devonian period in the Nalati arc (e.g. Jingbulake Cu‐Ni in Xinjiang), Carboniferous period in the Puerjin‐Ertai arc (e.g. Kalatongke Cu‐Ni‐Co‐PGE in Xinjiang), Carboniferous period in the Dananhu‐Touquan arc (e.g. Huangshandong, Xiangshan and Tulaergen in estern Tianshan, Xinjiang) to Triassic period in the Hulan arc (e.g. Hongqiling Cu‐Ni in Jilin). In addition to the overall tectonic, geologic and distribution of magmatic Cu‐Ni deposits in the Tianshan‐Xingmeng Orogenic Belt, the metallogenic setting, deposit geology and mineralization characteristics of each deposit mentioned above are summarized in this paper. Geochronologic data of Cu‐Ni deposits indicate that, from west to east, the metallogenic ages in the Tianshan‐Xingmeng Orogenic Belt changed with time, namely, from the Late Caledonian (∼440 Ma), through the Late Hercynian (300–265 Ma) to the Late Indosinian (225–200 Ma). Such variation could reflect a gradual scissor type closure of the paleo Asian ocean between the Siberia Craton and the North China Craton from west to east.