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The Awulale Iron Metallogenic Belt (AIMB) located in Central Tianshan is a significant iron ore belt in China. The Beizhan area exhibits extensive volcanic and intrusive rocks that formed during or close to the iron mineralization period. The iron ores in Beizhan are found in Early Carboniferous rhyolite and dacite tuff. The rhyolite is enriched in LILEs and LREEs, depleted in HFSEs, and shows high positive εNd(t) values (+3.0–+4.0). Late Carboniferous intrusive rocks include a granite stock and diabase and diorite dykes. The zircon grains from the granite yield a weighted mean 206Pb/238U age of 311.8 ± 2.6 Ma. The geochemical features of the granite are similar to those of rhyolite, but with pronounced negative anomalies of Eu, Sr, P, and Ti and higher positive εNd(t) values (+4.9–+5.1). The zircons in the diorite dyke yield a weighted mean 206Pb/238U age of 299.2 ± 1.4 Ma. Both the diabase and diorite dykes show an enrichment of LREEs and depletion of HFSEs with high positive εNd(t) values (+3.3–+7.3 and +2.3–+2.6, respectively), although the Eu, Th, and Sr anomalies are more negative in the diorite compared to the diabase. The rhyolite displays high positive εNd(t) values and young Nd model ages (TDM2 = 760–838 Ma) and has Nb/Ta ratios (11.3–12.8) close to that of the continental crust, indicating that it originated from the partial melting of the juvenile lower crust. The granite has similar geochemical characteristics (TDM2 = 656–673 Ma and Nb/Ta ratio = 8.7–10.9) and is also believed to have originated mainly from the partial melting of the juvenile lower crust. The diabase and diorite dykes have low (Tb/Yb)N ratios (<2) and high Ba/Th (31.8–353.2 and 185.3–251.3, respectively) and Sr/Th (113.8–312.9 and 144.7–163.1) ratios, and exhibit a pronounced depletion of HREEs and Y and negative Th anomalies, suggesting that they originated from a spinel-garnet lherzolite mantle source. The Early Carboniferous rhyolite erupted in a continental arc setting, whereas the Late Carboniferous granites, diabase dykes, and diorite dykes formed in an extensional setting associated with the upwelling of the asthenosphere. Therefore, the magmatism and Fe mineralization in the AIMB are correlated with an extensional setting associated with oceanic slab breakoff. [ABSTRACT FROM AUTHOR]

Most Neoproterozoic iron formations (NIF) are closely associated with global or near‐global "Snowball Earth" glaciations. Increasingly, however, studies indicate that some NIFs show no robust evidence of glacial association. Many aspects of non‐glacial NIF genesis, including the paleo‐environmental setting, Fe(II) source, and oxidation mechanisms, are poorly understood. Here, we present a detailed case study of the Jiapigou NIF, a major non‐glacial NIF within a Neoproterozoic volcano‐sedimentary sequence in North Qilian, northwestern China. New U–Pb geochronological data place the depositional age of the Jiapigou NIF at ~600 Ma. Petrographic and geochemical evidence supports its identification as a primary chemical sediment with significant detrital input. Major and trace element concentrations, REE + Y systematics, and εNd(t) values indicate that iron was sourced from mixed seawater and hydrothermal fluids. Iron isotopic values (δ56Fe = −0.04‰–1.43‰) are indicative of partial oxidation of an Fe(II) reservoir. We infer that the Jiapigou NIF was deposited in a redox stratified water column, where hydrothermally sourced Fe(II)‐rich fluids underwent oxidation under suboxic conditions. Lastly, the Jiapigou NIF has strong phosphorous enrichments, which in other iron formations are typically interpreted as signals for high marine phosphate concentrations. This suggests that oceanic phosphorus concentrations could have been enriched throughout the Neoproterozoic, as opposed to simply during glacial intervals. [ABSTRACT FROM AUTHOR]

Stem cell therapies are unsatisfactory due to poor cell survival and engraftment. Stem cell used for therapy must be properly "tuned" for a harsh in vivo environment. Herein, we report that transfer of exogenous mitochondria (mito) to adipose‐derived mesenchymal stem cells (ADSCs) can effectively boost their energy levels, enabling efficient cell engraftment. Importantly, the entire process of exogeneous mitochondrial endocytosis is captured by high‐content live‐cell imaging. Mitochondrial transfer leads to acutely enhanced bioenergetics, with nearly 17% of higher adenosine 5′‐triphosphate (ATP) levels in ADSCs treated with high mitochondrial dosage and further results in altered secretome profiles of ADSCs. Mitochondrial transfer also induced the expression of 334 mRNAs in ADSCs, which are mainly linked to signaling pathways associated with DNA replication and cell division. We hypothesize that increase in ATP and cyclin‐dependent kinase 1 and 2 expression might be responsible for promoting enhanced proliferation, migration, and differentiation of ADSCs in vitro. More importantly, mito‐transferred ADSCs display prolonged cell survival, engraftment and horizontal transfer of exogenous mitochondria to surrounding cells in a full‐thickness skin defect rat model with improved skin repair compared with nontreated ADSCs. These results demonstrate that intracellular mitochondrial transplantation is a promising strategy to engineer stem cells for tissue regeneration. [ABSTRACT FROM AUTHOR]

The Zhibo iron deposit is hosted in Carboniferous submarine volcanic rocks in Western Tianshan, NW China. A series of magnetite‐bearing intermediate‐mafic volcanic rocks are recognized in the periphery of the Zhibo ore district. Most of these volcanic rocks formed at 314 ± 2 Ma, possess tholeiitic–calc‐alkaline affinities, and display remarkable negative Nb, Ta, and Ti anomalies on primitive mantle‐normalized incompatible element diagrams. These features, together with those of their relatively complete rock assemblages and Th/Yb versus Nb/Yb diagrams, are indicative of their formation in an active continental margin arc setting. The wide compositional spectrum of SiO2 values ranging from 47.11 to 62.75 wt.% and lower Mg# values (55–63) of basalts suggest that the Zhibo intermediate‐mafic volcanic rocks may have experienced magmatic differentiation. Their (Th/Ta)PM > 1, (La/Nb)PM > 1, Nb/Ta (11‐16), and Th/Ce (0.06‐0.23) values suggest that the source of these intermediate‐mafic volcanic rocks was significantly contaminated by crustal materials. The magnetites in the iron ore have lower contents of Al, Mn, Ti, and V, indicating that the mineralization of magnetite in the iron ore occurred under lower temperature and higher oxygen fugacity conditions than those in the intermediate‐mafic volcanic rocks. In addition, the magnetites in the Zhibo iron ores have lower contents of compatible elements (e.g., Ti, V, Mn, Co, Cr, and Zn) than those of the magnetite in the intermediate‐mafic volcanic rocks, suggesting that the Zhibo magnetites crystallized from late‐stage, residual iron‐rich magmatic melts/magmatic‐hydrothermal fluids. In addition, the textures of the volcanic rocks suggest that iron have ever enriched in the residual melt during the magmatic stage, and the iron‐rich fragments in andesitic volcaniclastic rocks indicate that the ore‐forming material was a high‐salinity fluid‐bearing iron‐rich melt. In combination of available information, including field observations and geochemical analyses, we interpret that the Zhibo iron deposit is magmatic‐hydrothermal in origin. [ABSTRACT FROM AUTHOR]

The Awulale iron metallogenic belt (AIMB) hosts the majority of rich iron ores in Tianshan Orogen and has attracted much attention. However, a hot debate exists about the genesis of these iron deposits. Geochronological data are among the few critical evidences to solve the dispute. This study chooses the Beizhan iron deposit to carry out a geochronological research. The Beizhan magnetite deposit, with total iron ore reserves of 468 Mt at an average grade of 41% TFe, is the largest iron deposit in the AIMB. The orebodies of the Beizhan deposit are hosted in Carboniferous dacite and crystal tuff. Four stages of mineral formation can be recognized: an early skarn mineral stage, followed by the magnetite stage, the sulphide stage, and the carbonate stage in order. Pyrite separated from pyrite-rich ore samples yields an isochron age of 302.5 ± 8.2 Ma. Muscovite separated from muscovite-rich ore samples yields40Ar/39Ar plateau ages of 304.7 ± 1.8 Ma, 304.5 ± 1.9 Ma, 308.1 ± 1.9 Ma, and 307.2 ± 1.8 Ma, and isochron ages of 306.1 ± 3.5Ma, 304.0 ± 3.0Ma, 308.2 ± 3.1Ma, and 308.7 ± 3.1Ma, respectively. These ages are consistent within the error range and are interpreted as the age of the Beizhan iron deposit. The results, combined with the other latest precise dating and geologically inferred ages, demonstrate that the iron deposits in the AIMB were formed in the Late Carboniferous. These iron deposits are considered to be iron skarn or medium–low -temperature hydrothermal origin and have genetic linkages between each other. They may be different mineralizing manifestations proximal to or distal from a pluton. The Late Carboniferous iron ores and the related magmatic rocks in the AIMB were produced when upwelling of the asthenosphere causes the partial melting of various sources and the formation of a narrow linear extension in the upper crust. The upwelling of the asthenosphere may be triggered by the detachment of an orogenic root zone. [ABSTRACT FROM AUTHOR]