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• The 2.2 Ga monzogranite identified in the western part of the North Qinling Orogen (NQO) was originally formed in the southwestern North China Craton (NCC). • The monzogranite was involved into the NQO by continental collision between the NQO and the NCC during the early Paleozoic. • The early Precambrian rocks at the southwestern margin of the Ordos Blocks recorded similar tectono-thermal events of 2.5–1.75 Ga with the basement of the central-southern Ordos Block. Precambrian continent remnants in Phanerozoic orogenic belts contain vital information about not only the Precambrian evolution history of continent remnants but also the relationship between orogenic belts and adjacent blocks. This paper presents an integrated study of petrology, geochemistry and accessory mineral chronology on a monzogranite, its wall rocks biotite-quartz schist and an amphibolite interlayer in the schist in the Kuanping Group, from the western part of the North Qinling Orogen (NQO), adjacent to the southwestern margin of the Ordos Block (OB). The results reveal that the crystallization age of the monzogranite is 2200 ± 12 Ma and the protolith of the biotite-quartz schist deposited during 526–447 Ma, and they experienced similar multistage metamorphism during 450–400 Ma. The 2.2 Ga formation age of the monzogranite is significantly older than the protolith deposition age of the biotite-quartz schist, and there is almost no ca. 2.2 Ga detrital zircon age in the schist, indicating that the monzogranite is neither an intrusive body in the Kuanping Group, nor its provenance. Considering the ca. 2.2 Ga magmatism is widely distributed in North China Craton but never found in the NQO, and the monzogranite and host schist recorded similar metamorphic ages, we proposed that the monzogranite initially formed at the southwestern margin of the North China Craton and involved into the NQO during the closure of the Kuanping sedimentary basin at early Paleozoic. Combined with existing studies, three Paleoproterozoic magmatic events of ca. 2.5 Ga, 2.2–2.0 Ga and 1.8–1.75 Ga, and one ca. 1.9–1.85 Ga metamorphic event occurred at the southwestern margin of OB. These tectono-thermal events as well as their geological setting are very similar to the basement rocks of the central-southern part of the OB. Therefore, the early Precambrian rocks at the southwestern margin of the OB should belong to the basement of the central-southern part of OB, and the late tectonic events placed them at their present position. [ABSTRACT FROM AUTHOR]

• Three episodes granitic magmatism at ca. 1420 Ma, ca. 900 Ma and 780–750 Ma were identified in drill cores from the Qaidam basin. • Ca. 1.8–1.1 Ga, 1.0–0.9 Ga and 850–750 Ma three tectonic-thermal events of the Qaidam block correspond to the fragmentation of Columbia and the assembly and breakup of Rodinia. • The Qaidam block and Tarim craton likely constituted a unified block, and located at interior of Columbia but peripheral of Rodinia during Meso–Neoproterozoic. As a micro-continent lying at the junction of the North China, Yangtze, and Tarim Cratons in northwest China, the composition and tectonic-thermal history of the Qaidam Block not only are crucial for determining its tectonic attribute and relationships with surrounding cratons, but also can provide key constraints on convergence, fragmentation, and paleogeographic reconstruction of Columbia and Rodinia. In this study, systematic petrology, geochemistry, and zircon U–Pb–Hf isotope analyses were conducted on newly discovered Meso-Neoproterozoic granitic rocks from drill cores in the Qaidam basin and three stages granitic magmatism at ca. 1420 Ma, ca. 900 Ma and 780–750 Ma are yielded. The ca. 1420 Ma granitic rocks exhibit characteristics of highly fractionated I-type granites, with high Yb but low Sr contents, low Sr/Y and La/Yb ratios, high zircon saturation temperatures (774–831 ℃), and positive ε Hf (t) values (–0.04 to +11.35) with T DM2 values of 2178–1468 Ma, suggesting that they were mainly derived from the ancient crust with mantle magma input under an extensional setting. The ca. 900 Ma granitic rocks have high A/CNK values (1.01–1.21) and variable zircon ε Hf (t) values (–1.93 to + 6.58) with T DM2 ages between 1402 and 1910 Ma, indicating they are S-type granites formed by partial melting of sedimentary rocks in thickened crust. The ca. 780–750 Ma granites have high Zr + Nb + Ce + Y contents, 10000* Ga/Al ratios, and crystallization temperatures (mean = 808 ℃), belonging to the A 1 -type granite formed in a continental rift setting. Combined with the previous researches, the Meso-Neoproterozoic tectonic-thermal events in the Qaidam Block can be divided into three stages, 1.8–1.1 Ga, 1.0–0.9 Ga and 850–750 Ma, corresponding to the fragmentation of Columbia, and the assembly and breakup of Rodinia, respectively. Comparing the Qaidam Block with the surrounding blocks and the major cratons in Columbia and Rodinia, it is considered that the Qaidam Block was splited from the Tarim Craton and they may have occupied an interior position in Columbia but a peripheral position in Rodinia, connecting to the India and East Antarctica. [ABSTRACT FROM AUTHOR]

• A theoretical framework for environmental impacts of urban sprawl was introduced. • A PSR index system was built to measure eco-environmental effects of urban sprawl. • Spatiotemporal differentiation of urban sprawl eco-environmental effects was observed. • Considering eco-environmental effects in urban planning is feasible and promising. Urban sprawl and its eco-environmental impacts are crucial components of global environmental change research, and a core issue for sustainable development. In this study we used a Pressure-State-Response (PSR) system to develop a theoretical framework, in which the total eco-environmental effects of urban sprawl (EEUS) were divided into pressure, state, and response. A corresponding index system was then constructed to evaluate the different kinds of EEUS in China's 30 provinces from 2003 to 2015, and temporal and spatial characteristics are explored through spatial autocorrelation analysis. We found that 1) pressure, state and response EEUS not only had differences but also strong connections. These three kinds of eco-environmental effects also had different causal mechanisms and their contributions to the total EEUS were different. 2) The pressure, state and response, as well as the total EEUS, increased from 2003 to 2015. However, there were clear disparities in EEUS across the eastern, central, western and northeast regions. EEUS results for the eastern and northeast regions were higher than in the central and western regions. 3) There was significant spatial dependence and heterogeneity in EEUS. Overall, the spatial difference in EEUS was mainly caused by "HH" and "LL" cluster types. These results have significant implications for theoretical guidance and policy efforts. We conclude that a better eco-environment in the process of urban sprawl can be achieved by improving the quality of urban development and enhancing government management. [ABSTRACT FROM AUTHOR]

Water dissolved in nominally anhydrous minerals (NAMs) can be transported to deep regions of the Earth through subducting slabs, thereby significantly influencing the physicochemical properties of deep-Earth materials and impacting dynamic processes in the deep Earth. Stishovite, a prominent mineral present in subducting slabs, remains stable at mantle pressures of 9–50 GPa and can incorporate various amounts of water (H + , OH - , and H 2 O) in its crystal structure. Consequently, stishovite can play a crucial role in transporting water into the deep Earth through subducting slabs. This paper provides a comprehensive review of the research process concerning water (hydrogen) solubility in stishovite. The key factors that govern water solubility in stishovite are summarized as temperature, pressure, water fugacity, and aluminum content. Combined with published results on the dependence of water solubility on the aforementioned parameters, this paper proposes a new equation to describe the solubility of water in Al-bearing stishovite. Calculation results based on this equation suggest that stishovite may effectively accommodate water released from processes such as hydrous mineral breakdown, which could ultimately contribute to the presence of a water-rich transition zone. [ABSTRACT FROM AUTHOR]

An integrated study including petrography, mineral chemistry, metamorphic P–T path modelling, and zircon U–Pb dating was conducted on a granitic gneiss and enclosed eclogite from South Dulan, North Qaidam UHP (ultrahigh-pressure) belt. The result shows that the granitic gneiss underwent a clockwise P–T path with a peak-P stage at 655–745°C, 30–34 kbar, and a subsequent peak-T stage at 815–870°C, 14–18 kbar, which is similar to the P–T estimates reported for coesite-bearing continental-type eclogites in this region. The enclosed eclogite resembles an olivine–pyroxene-rich cumulate in Qaidam block. It has a similar prograde P–T path with the country gneiss and experienced a peak-P stage of 682–748°C at 27–34 kbar. Zircon U–Pb dating yields an eclogite-facies metamorphic age of 447 ± 2 Ma for the granitic gneiss and 445 ± 6 Ma for the enclosed eclogite. These ages agree with metamorphic ages obtained from paragneisses (427–439 Ma), coesite-bearing continental-type eclogites (430–451 Ma), and UHPM (ultrahigh-pressure metamorphic) oceanic crust–mantle sequence (440–445 Ma) from South Dulan, as well as UHP eclogites, garnet peridotite, and gneisses from other units (460–420 Ma) within this belt reported by others. Similar metamorphic ages as well as P–T evolution documented in gneisses and intercalated eclogites imply that both rocks experienced a coeval UHP event. Summarizing all the published geochronology data, we argue that the North Qaidam UHP belt was mainly formed by continental deep subduction at ~460 to ~420 Ma. The UHPM oceanic crust-mantle sequence in South Dulan may represent oceanic lithosphere in the transition zone between oceanic and continental crust, which was dragged upward by the exhumed continental rocks after break-off of the dense oceanic crust. [ABSTRACT FROM PUBLISHER]

• A clockwise P–T path was established for Chachahe eclogites in North Qaidam UHP belt, NW China. • The Chachahe eclogites experienced a 1.92 Ga metamorphic event prior to eclogitization at ∼ 450 Ma. • Overriding plate material can enter subduction channel via tectonic erosion and be carried to mantle depths of ≥ 85 km. Although numerical modelling and marine seismic data show that overriding plate material can enter subduction channel and even recycle to mantle, and finally contribute to mantle heterogeneity and arc magmas, protoliths of the majority of high pressure (HP) and ultrahigh pressure (UHP) metamorphic rocks on the earth's surface originate from the subducting plate. Whether overriding plate material can enter subduction channel and their fate in subduction channel remain enigmas. The North Qaidam UHP Metamorphic Belt (NQUB), located in northwestern China, was formed by north-dipping subduction of the Qaidam Block beneath the Quanji block in the Early Paleozoic. In this paper, we report that some eclogites in Chachahe area, NQUB experienced a 1.92 Ga low-grade metamorphism prior to eclogitization at ∼ 450 Ma. This Paleoproterozoic metamorphic event is not reported in the subducted Qaidam Block but widespread in the overriding Quanji Block, indicating that protoliths of Chachahe eclogites originated from the overriding plate. A clockwise P–T path from 12 kbar/520 °C to near UHP conditions of 25.5 kbar/690 °C, followed by isothermal decompression, was estimated for the Early Paleozoic metamorphism using a combination of garnet major and trace element zoning, phase equilibrium modelling and thermobarometry. This P–T path pattern is similar to other eclogites in this area, protoliths of which originated from the subducted plate. These results clearly show that overriding plate material can enter subduction channel and be carried to mantle depths of at least 85 km and exhume fast along subduction channel with other slices from subducted slab. [ABSTRACT FROM AUTHOR]

A lot of previous experimental studies on ultramafic rocks (SiO2 unsaturated system) (Ringwood and Major, 1971; Irifune et al., 1986; Gasparik, 1989; Ono and Yasuda, 1996) have demonstrated that characteristics of Si‐rich and Al‐deficient in garnet are resulted from coupled substitution of SiVI+MVI=AlVI+AlVI and SiVI+NaVII=AlVI+MVII (M=Mg, Fe, Ca) at ultrahigh pressures (UHP) (>5 GPa). The degree of substitution will be enhanced by increasing pressure which has a positive correlation with the content of SiVI, but a negative correlation with the content of AlVI in supersilic garnet. These experimental results established a theoretical foundation for further understanding the formation mechanism of the exsolution of pyroxene in garnet observed in deep mantle xenoliths and some ultrahigh pressure rocks, and also for estimating the pressure conditions of the formation of supersilic garnet before exsolution (Haggerty and Sautter, 1990; Sautter et al., 1991; van Roermund et al., 1998; Ye et al., 2000). Although some experimental studies on SiO2 saturated system have been reported (Irifune et al., 1994; Ono., 1998; Dobrazhinetskya and Green., 2007; Wu et al., 2009), the stability conditions of supersilic garnet are still lack of unified understanding. Therefore, HP‐HT experiments were carried out on felsic rocks under conditions of 6–12GPa and 1000°C–1400°C. Combined with previous experimental data, we try to figure out the minimum stable pressure and geological significants of supersilic garnet in SiO2 saturated system. Our experimental results from SiO2 saturated system show the minimum stable pressure of supersilic garnet should be ≥10 GP of stishovite stability field. These results are similar as that from experiments using starting composition similar to average upper continental crust reported by Irifune et al (1994) who yielded that garnet gradually became supersilic and Al‐deficient as pressures increased above 10 GPa, especially in a pressure interval between 13 and 18 GPa. Moreover, experiments with different starting materials (Ono, 1998; Dobrazhinetskya and Green, 2007; Wu et al. 2009) also indicate the stable pressure condition of supersilic garnet is mainly ≥9 –10 GPa in SiO2 saturated system if data of small‐size grains at low temperature are ignored due to measuring errors. Thus, it can be concluded that the minimum stable pressure of supersilic garnet in SiO2 saturated system is distinctly different from that in SiO2 unsaturated ultramafic rock system. The minimum pressure of the former is ≥9–10 GPa of stishovite stability field, while that of the latter is >5 GPa. Therefore, whether independent SiO2 phase exist or rock system is SiO2 saturated must be taken into considered when estimating the peak pressure of exsolutions in supersilic garnet in UHP rocks. Furthermore, pressure of >5 GPa directly estimated by supersilic garnet based on conclusion from SiO2 unsaturation system rather than SiO2 saturation in previous sdudies may have been underestimated and need to be re‐estimated. Supersilic garnets have been recognized by interior exsolutions of clinopyroxene in garnet pyroxene from Yinggelisayi South Altyn (Liu et al., 2005), and exsolutions of rodlike quartz+rutile in felsic gneiss from Songshugou North Qinling (Liu et al., 2003). According to the experimental results from SiO2 unsaturated system, the peak metamorphic pressure of the both SiO2 saturated rocks have been estimated to be >7Gpa and >5Gpa, respectively. However, combined with the new experimental results above, we re‐estimated that the peak metamorphic pressure of these SiO2 saturated rocks should be≥9 –10 GPa at least, implying an ultra‐deep subduction to mantle depth of stishovite stability field. This research, together with previous findings (Liu et al., 2007, 2018), shows that continental subduction to mantle depth (300km) of stishovite stability field and then exhumation to the surface is obviously more common than previously thought, and the rock types are also diverse. At the same time, it provides a new indicator and thought for recognizing the subduction to the mantle depth of stishovite stability field in UHP metamorphic belt. [ABSTRACT FROM AUTHOR]

A lot of previous experimental studies on ultramafic rocks (SiO2 unsaturated system) (Ringwood and Major, 1971; Irifune et al., 1986; Gasparik, 1989; Ono and Yasuda, 1996) have demonstrated that characteristics of Si‐rich and Al‐deficient in garnet are resulted from coupled substitution of SiVI+MVI=AlVI+AlVI and SiVI+NaVII=AlVI+MVII (M=Mg, Fe, Ca) at ultrahigh pressures (UHP) (>5 GPa). The degree of substitution will be enhanced by increasing pressure which has a positive correlation with the content of SiVI, but a negative correlation with the content of AlVI in supersilic garnet. These experimental results established a theoretical foundation for further understanding the formation mechanism of the exsolution of pyroxene in garnet observed in deep mantle xenoliths and some ultrahigh pressure rocks, and also for estimating the pressure conditions of the formation of supersilic garnet before exsolution (Haggerty and Sautter, 1990; Sautter et al., 1991; van Roermund et al., 1998; Ye et al., 2000). Although some experimental studies on SiO2 saturated system have been reported (Irifune et al., 1994; Ono., 1998; Dobrazhinetskya and Green., 2007; Wu et al., 2009), the stability conditions of supersilic garnet are still lack of unified understanding. Therefore, HP‐HT experiments were carried out on felsic rocks under conditions of 6–12GPa and 1000°C–1400°C. Combined with previous experimental data, we try to figure out the minimum stable pressure and geological significants of supersilic garnet in SiO2 saturated system. Our experimental results from SiO2 saturated system show the minimum stable pressure of supersilic garnet should be ≥10 GP of stishovite stability field. These results are similar as that from experiments using starting composition similar to average upper continental crust reported by Irifune et al (1994) who yielded that garnet gradually became supersilic and Al‐deficient as pressures increased above 10 GPa, especially in a pressure interval between 13 and 18 GPa. Moreover, experiments with different starting materials (Ono, 1998; Dobrazhinetskya and Green, 2007; Wu et al. 2009) also indicate the stable pressure condition of supersilic garnet is mainly ≥9 –10 GPa in SiO2 saturated system if data of small‐size grains at low temperature are ignored due to measuring errors. Thus, it can be concluded that the minimum stable pressure of supersilic garnet in SiO2 saturated system is distinctly different from that in SiO2 unsaturated ultramafic rock system. The minimum pressure of the former is ≥9–10 GPa of stishovite stability field, while that of the latter is >5 GPa. Therefore, whether independent SiO2 phase exist or rock system is SiO2 saturated must be taken into considered when estimating the peak pressure of exsolutions in supersilic garnet in UHP rocks. Furthermore, pressure of >5 GPa directly estimated by supersilic garnet based on conclusion from SiO2 unsaturation system rather than SiO2 saturation in previous sdudies may have been underestimated and need to be re‐estimated. Supersilic garnets have been recognized by interior exsolutions of clinopyroxene in garnet pyroxene from Yinggelisayi South Altyn (Liu et al., 2005), and exsolutions of rodlike quartz+rutile in felsic gneiss from Songshugou North Qinling (Liu et al., 2003). According to the experimental results from SiO2 unsaturated system, the peak metamorphic pressure of the both SiO2 saturated rocks have been estimated to be >7Gpa and >5Gpa, respectively. However, combined with the new experimental results above, we re‐estimated that the peak metamorphic pressure of these SiO2 saturated rocks should be≥9 –10 GPa at least, implying an ultra‐deep subduction to mantle depth of stishovite stability field. This research, together with previous findings (Liu et al., 2007, 2018), shows that continental subduction to mantle depth (300km) of stishovite stability field and then exhumation to the surface is obviously more common than previously thought, and the rock types are also diverse. At the same time, it provides a new indicator and thought for recognizing the subduction to the mantle depth of stishovite stability field in UHP metamorphic belt. [ABSTRACT FROM AUTHOR]

• Urban sprawl (UBS) index and eco-environmental quality (EEQ) index are built. • The impact of UBS on EEQ is investigated theoretically and empirically. • Spatial Durbin model is used, taking China's provincial panel data from 2003 to 2018. • Population sprawl, socio-economic sprawl, transportation sprawl, and land use sprawl explain EEQ change. • It is necessary to incorporate the spatial effect into urban development planning. Rapid urban sprawl in China has caused serious eco-environmental changes, and thus attracted significant attention of the international academic circles. However, the mechanism of influence of urban sprawl on eco-environmental quality has not been addressed adequately. The main objective of this study was to fill this gap by theoretically and empirically studying how urban sprawl influences eco-environmental quality, based on the Spatial Durbin model and on a panel data covering 30 provinces of mainland China during the period 2003–2018. The results show that China's urban sprawl has significantly decreased the eco-environmental quality under both geographical and economic weight matrices. Moreover, the spillover effect played an essential role in investigating the influence of urban sprawl on eco-environmental quality. From the perspective of regional differences, the direct accumulation effect and the spatial spillover effect involved in the impact of urban sprawl on eco-environmental quality varied across the central, western, and northeast regions. The results of decomposition of urban sprawl into its component parts indicate that population sprawl, socio-economic sprawl, transportation sprawl, and land use sprawl can explain the change of eco-environmental quality in China to varying degrees. During the study period, land use sprawl exhibited the greatest effect on eco-environmental quality, followed by socio-economic sprawl, population sprawl, and transportation sprawl. The government should actively coordinate the development of different types of urban sprawl, thus increasing eco-environmental quality across different regions. [ABSTRACT FROM AUTHOR]

A combined study of CL imaging, LA-ICP-MS U-Pb dating and trace element analysis were carried out for zircon grains from high-pressure basic granulite at Songshugou in North Qinling. The zircons display core-rim internal texture. The cores are made up of sector or planar domains, partially displaying weak zoning or misty texture, and have the feature of low content of Th, U, REE, HREE, low Th/U ratio and high (Nd/Yb)N ratio, and the REE pattern typical for zircon coexisting with garnet. These features indicate the metamorphic genesis for the zircon cores. The rims have narrow light margins (<30 μm in width) around the cores and boundaries between core and rim are rounded or lough-like, indicating that the rims were formed during retrograde metamorphism. U-Pb isotopic data of 24 spots from the cores of 11 zircon grains yield a 206Pb/238U weighted average age of 485±3.3 Ma, which is interpreted as the peak metamorphic age of high-pressure (HP) basic granulite. This age is well consistent within error with that of ultrahigh-pressure (UHP) eclogite and its country rock gneiss (507±37 Ma) that occur at the north side of the Qinling Group, possibly indicating the occurrence of two contemporaneous Early-Paleozoic HP to UHP metamorphic rock belts on the north and south sides of the Qinling Group. Combining with the regional geological studies and the distribution of Early-Paleozoic granites related to subduction and collision, the two HP to UHP metamorphic belts may be the products of continental crust bi-directional deep subduction toward Qinling micro-block caused by the subduction and collision of Paleozoic Qinling ocean and Erlangping ocean, respectively. [ABSTRACT FROM AUTHOR]

• The Hudian monzonitic granite and its dark enclaves were formed at ca. 1.77–1.78 Ga and metamorphosed at ca. 400 Ma. • The Hudian pluton was formed in the southern North China Craton (NCC) in a continental rift environment. • The Hudian monzonitic granite was involved in the North Qinling Orogen Belt (NQOB) at ca. 400 Ma. Before this convergent process, the NQOB has no relation to the NCC. The Hudian gneissic monzonitic granite with lentoid dark enclaves and foliated mafic dykes was exposed in the western segment of the North Qinling Orogenic Belt (NQOB). It has long been considered as an intrusion into the Kuanping Complex, the northernmost component of the NQOB. LA–ICP–MS zircon dating yields consistent formation age of ca. 1.77 Ga for the granite and dark enclaves and the same metamorphic age of ca. 400 Ma for the granite and the mafic dykes. The formation age of ca. 1.77 Ga of the Hudian pluton is much older than the deposition age (<530 Ma) of its wall-rock Kuanping clastic rocks and no detrital zircon age of ca. 1.77 Ga was found in the Kuanping clastic rocks, suggesting that the Hudian monzonitic granite is not an intrusion in the clastic rocks, and the pluton was far apart when the Kuanping clastic rocks were deposited. The granite is low in Al 2 O 3 , CaO, MgO and Mg# high in SiO 2 , Na 2 O + K 2 O, Fe 2 O 3 T, Zr and 10,000*Ga/Al, and displays slightly right dipping "gull-wing" shaped rare earth element patterns, agreeing well with the features of A-type granites; the dark enclaves are basalt-andesitic rocks and show characteristics of crust-contaminated continental within-plate basaltic rocks, all suggesting a tectonic setting of extension. The major and trace element compositions of the Hudian monzonitic granite and its dark enclaves and the zircon ε Hf (t) values (−12.1 to −7.1) of the Hudian monzonitic granite all show strong comparability to the 1.75–1.8 Ga A-type granites and coeval intermediate-basic rocks of the Xiong'er Group in the southern North China Craton (NCC), indicating that the Hudian pluton maybe initially formed in the southern NCC. Considering the absence of obvious 1.75–1.8 Ga detrital zircon records in the Kuanping Complex, and the common metamorphic age of ca. 400 Ma in the Kuanping Complex and Hudian pluton as well as other units of the NQOB, we propose that the NCC has no affinity to the NQOB and the Hudian pluton was involved in the NQOB during the collision between the southern NCC and the NQOB at ca. 400 Ma. [ABSTRACT FROM AUTHOR]

The North Qaidam Belt (NQDB) is an Early Paleozoic continental ultrahigh-pressure (UHP) metamorphic belt between the Qaidam Block and South Qilian Belt (SQB) in northwest China, and the UHP metamorphic rocks recorded differential/diachronous exhumation and anatexis histories. To constrain the multi-stage exhumation and the associated magmatism of the NQDB and its adjacent areas, an integrated study of petrology, geochemistry, zircon U Pb and Lu Hf isotopes was conducted on the OIB-like dolerite and A-type dacite porphyry from the SQB. The OIB-like dolerite is enriched in light rare-earth elements (LREEs), large ion lithophile elements (LILEs), and high field strength elements (HFSEs), and depleted in heavy rare-earth elements (HREEs), with a crystallization age of 425 ± 7 Ma and zircon ε Hf (t) values ranging from −4.2 to 0.3. Given that the oceanic/continental deep subduction occurred in this area during Early Paleozoic, the fertile mantle source of OIB-like dolerite was likely formed by the crust-mantle interaction between the oceanic crust and juvenile lithospheric mantle at the instability field of rutile above the subduction zone. The A-type dacite porphyry is enriched in Al, Fe, LILEs and LREEs, depleted in Ca, Mg, Ba, Sr, Eu and HFSEs, and is characterized by high Zr concentrations (231–271 ppm), 10,000*Ga/Al ratios (2.51–2.73) and crystallization temperatures (738–836 °C). Zircon U Pb and Lu Hf isotopic data reveal the dacite porphyry crystalized at 423 ± 5 Ma with zircon ε Hf (t) values ranging from −8.9 to −3.3. The inherited magmatic zircons gave a formation age of 472 ± 8 Ma with ε Hf (t) values ranging from −3.9 to −1.9, contemporaneous with the oceanic subduction-related magmatism in the NQDB, indicating the dacite porphyry may be derived from the Early Paleozoic arc. Combined with the previous studies on the UHP metamorphism (ca. 458–420 Ma), retrograde metamorphism (ca. 432–397 Ma), and anatexis (ca. 436–417 Ma) in the NQDB, we conclude that the breakoff of the oceanic lithosphere from the continental lithosphere triggered the thermal perturbation from the asthenosphere upwelling at ca. 425 Ma and the subsequent partial melting of the fertile metasomatized mantle and Early Paleozoic arc, forming the OIB-like dolerite and A-type dacite porphyry in the SQB. Moreover, the coeval mafic and felsic magmatism indicates an important tectonic transformation that the subducted continental crust experienced a localized detachment/exhumation before ca. 425 Ma and entire exhumation after slab breakoff. • Coeval (425–423 Ma) dolerite and dacite porphyry in the South Qilian Belt. • These magmas were caused by the slab breakoff. • The subducted continental plate experienced two stages of exhumation in the NQDB. [ABSTRACT FROM AUTHOR]

The North Qaidam orogenic belt (NQOB) lies at the northeast margin of Tibet Plateau, between the Qilian massif to the north and Qaidam massif to the south. It consists of predominantly gneisses and marbles with minor eclogite and garnet peridotite, and is known as an Early Paleozoic continental deep subduction ultrahigh pressure (UHP) metamorphic belt in northwest China. Recently some studies suggest that the NQOB experienced oceanic deep subduction prior to the continental deep subduction. However, the records of ocean events are rarely preserved because of the complex multi‐stage transformation. Therefore, whether the Early Paleozoic ocean exists and the formation, nature and evolution of the Early Paleozoic ocean in North Qaidam are still in controversies. In this contribution, we report a new discovered SSZ‐type ophiolite suite in Kaipinggou area, the western segment of the NQOB. The ophiolite is mainly composed of peridotite, gabbro, basalt, boninite, andesitic porphyrite and plagiogranite. In which, the basalt and homogeneous gabbro are both enriched in LILE and depleted in HFSE, and display flat or LREE‐depleted REE patterns, similar to the MORB‐like geochemical characteristics of fore‐arc basalts; the boninite exhibits characteristics of fore‐arc boninites with high Si and Mg, but low Ti and Ca contents; the andesitic porphyrite is enriched in LILE but depleted in HFSE, similar to island arc magmatic rocks. Rock assemblage and their geochemical characteristics suggest that this SSZ‐type ophiolite was formed in fore‐arc setting of intra‐oceanic arc. The plagiogranite is a low‐potassium tholeiite metaluminous granite with low trace elements contents, slight enrichment of LREE, depletion of HREE and positive Eu anomaly; combining with ∊Hf (t) values (13.8–17.1) of zircons, the plagiogranite could be originated from partial melting of gabbros. LA–ICP–MS zircon U–Pb dating yielded the crystallization ages of 535±2 Ma, 513±3 Ma and 510±3 Ma for two cumulate gabbros and one homogeneous gabbro, respectively, and a formation age of 492±8 Ma for the plagiogranite. All these data suggest the existence of an Early Paleozoic ocean in the North Qaidam, and the initial subduction of the oceanic slab occurred earlier than 535Ma. [ABSTRACT FROM AUTHOR]

The North Qaidam orogenic belt (NQOB) lies at the northeast margin of Tibet Plateau, between the Qilian massif to the north and Qaidam massif to the south. It consists of predominantly gneisses and marbles with minor eclogite and garnet peridotite, and is known as an Early Paleozoic continental deep subduction ultrahigh pressure (UHP) metamorphic belt in northwest China. Recently some studies suggest that the NQOB experienced oceanic deep subduction prior to the continental deep subduction. However, the records of ocean events are rarely preserved because of the complex multi‐stage transformation. Therefore, whether the Early Paleozoic ocean exists and the formation, nature and evolution of the Early Paleozoic ocean in North Qaidam are still in controversies. In this contribution, we report a new discovered SSZ‐type ophiolite suite in Kaipinggou area, the western segment of the NQOB. The ophiolite is mainly composed of peridotite, gabbro, basalt, boninite, andesitic porphyrite and plagiogranite. In which, the basalt and homogeneous gabbro are both enriched in LILE and depleted in HFSE, and display flat or LREE‐depleted REE patterns, similar to the MORB‐like geochemical characteristics of fore‐arc basalts; the boninite exhibits characteristics of fore‐arc boninites with high Si and Mg, but low Ti and Ca contents; the andesitic porphyrite is enriched in LILE but depleted in HFSE, similar to island arc magmatic rocks. Rock assemblage and their geochemical characteristics suggest that this SSZ‐type ophiolite was formed in fore‐arc setting of intra‐oceanic arc. The plagiogranite is a low‐potassium tholeiite metaluminous granite with low trace elements contents, slight enrichment of LREE, depletion of HREE and positive Eu anomaly; combining with ∊Hf (t) values (13.8–17.1) of zircons, the plagiogranite could be originated from partial melting of gabbros. LA–ICP–MS zircon U–Pb dating yielded the crystallization ages of 535±2 Ma, 513±3 Ma and 510±3 Ma for two cumulate gabbros and one homogeneous gabbro, respectively, and a formation age of 492±8 Ma for the plagiogranite. All these data suggest the existence of an Early Paleozoic ocean in the North Qaidam, and the initial subduction of the oceanic slab occurred earlier than 535Ma. [ABSTRACT FROM AUTHOR]

• Some eclogites experienced ca. 929–916 Ma amphibolite-facies and ca. 439–430 UHP metamorphism. • The Neoproterozoic metamorphism is related to the assembly of the supercontinent Rodinia. • Mesoproterozoic to early Paleozoic tectonic evolution of the NQOB is reconstructed. • The Qaidam Block was probably the eastward extension of the Tarim Block during the Neoproterozoic. Eclogites documenting two orogenic cycles not only contain essential information on subduction and exhumation mechanisms during the most recent orogenic cycle, but can also provide insights into the earlier cycle. Such rocks are ideal for deciphering the tectonic evolution of orogenic belts with a multi-orogenic history. This is the case for the North Qaidam orogenic belt (NQOB) in northwest China where, for the first time, we have discovered eclogites that preserve a record of two orogenic cycles. The first orogenic event occurred at ca. 929–916 Ma and the second at ca. 439–430 Ma. The metamorphic P–T conditions of these two events were 5.0–7.0 kbar/616–669 °C and 29.0–32.5 kbar/620–670 °C, respectively. Zircon U–Pb dating yielded protolith ages of 1280–1070 Ma for these eclogites, which are much older than the protolith ages for other eclogites in the NQOB. The eclogites exhibit chondrite-normalized rare earth element patterns that are flat or depleted in light rare earth elements, similar to present-day N- and E-MORB. Magmatic zircon cores from the eclogites have high ε Hf (t) values of 8.4 ± 4.0 to 18.1 ± 1.1, comparable to depleted mantle within uncertainty, and indicating a juvenile crustal origin. Our data show that the eclogite protoliths were probably pre-Rodinia Mesoproterozoic oceanic crust that was emplaced in an active continental margin during oceanic subduction, and experienced Neoproterozoic metamorphism related to the amalgamation of Rodinia and early Paleozoic continental deep subduction. Using published data for all eclogites and their host gneisses, we reconstructed the Mesoproterozoic to early Paleozoic tectonic evolution of the NQOB. Given the similar Meso–Neoproterozoic evolution of the NQOB and adjacent Tarim Block, we suggest that the Qaidam Block was the eastward extension of the Tarim Block during the Neoproterozoic. [ABSTRACT FROM AUTHOR]

The long prism/needle‐shaped polycrystalline quartz aggregates and square/parallelogram‐shaped singlephase quartz inclusions in omphacite and garnet of ultrahigh pressure eclogite were first discovered from the Jiangalesayi area, South Altyn UHP belt. Based on their morphology, these quartz inclusions are quartz paramorphs after stishovite. The minimum peak pressure of the eclogite is estimated to be >8–9 GPa at 800– 1000 °C based on the stability field of stishovite. This new evidence, together with previous stishovite exsolution microstructure in the gneiss from the same region, suggests an ultra‐deep subduction and exhumation of the South Altyn continental rocks to/from mantle depths in stishovite stability field. Evidence of ultra‐deep subduction of continental materials might be more common and diverse than previous thought. Exhumation of subducted continental rocks from≥300 km has been considered impossible because they are denser than mantle at these depths. How did the stishovite bearing continental rocks of the South Altyn exhumated? As we all know, the densities of stishovite (4.3 g/cm3) are much higher than coesite (2.9 g/cm3), and stishovite transforms into coesite with temperature increases. Density calculations were performed for subducted continental rocks along phase transition of stishovite to coesite, using the third‐order Birch‐Murnaghan equation of state based on mineral fractions obtained from experiments and Perple_X. The results show that the density of Siliceous rocks decrease remarkably, lower than the surrounding mantle in coesite stability field, whereas the density of Oligosiliceous and Silicon unsaturated rocks is higher than surrounding mantle. Thus, we propose that the thermal induced transformation could provide an initial driven force for the exhumation of ultra‐deep subducted silica‐enriched felsic continental rocks. Temperature increase could be derived from an increased geothermal gradient from convective mantle or mantle plume. Mafic to ultra‐mafic rocks and silica‐deficient rocks may be captured by the upwelling subducted continental rocks and exhumated together. [ABSTRACT FROM AUTHOR]

The North Qaidam is an Early Paleozoic UHP metamorphic belt located at the north margin of the Tibet plateau. Eclogites in this belt contain both continental‐and oceanic‐type ones. In which, the continental‐type eclogites have protolith ages of 750–850 Ma and WPB or CFB geochemical signatures and are believed to have formed in a continental rift or an incipient oceanic basin setting related to the breakup of the Rodinia supercontinent, their metamorphic ages (421–458 Ma) and P–T paths are comparable to their host gneisses; oceanic‐type eclogites have cumulate gabbro or E‐MORB geochemical signatures, their protolith and metamorphic ages are 510–516 Ma and 425–450 Ma, respectively(Zhang et al., 2008). Therefore, the North Qaidam UHP belt was thought to record the whole Neoprotoerozoic–Paleozoic Wilson cycle (Song et al., 2014). In this study, we reported three new kinds of eclogites: kyanite‐bearing eclogite, lawsonite pseudomorph‐bearing eclogite and double mineral eclogite. They occur as big lentoid blocks in regional granitic gneiss in the western part of the belt. Phase equilibrium modelling and zircon LA‐ICPMS U‐Pb dating show that all these three eclogites experienced a clockwise P–T path with peak metamorphic conditions close to or fall in the coesite stability field, and their peak metamorphic age were around 436‐439 Ma, similar to those continental‐type eclogites in this belt. But their protolith ages are between 1273 and 1070 Ma, and some of them recorded an amphibolite facies metamorphic age of 927 Ma, and geochemical data and zircon Lu‐Hf and O isotope analysis indicate these eclogites have features of present day N‐MORB. Combined with the existing results, we propose that the North Qaidam is a polycyclic composite orogenwhich recorded tectonic evolution of Mesoproterozoic ocean floor spreading, assembly and breakup of Rodinia supercontinent, Early Paleozoic oceanic deep subduction and subsequently continental deep subduction. [ABSTRACT FROM AUTHOR]

Aqueous zinc ion batteries are gaining popularity due to their high energy density and environmental friendliness. However, random deposition of zinc ions on the anode and sluggish migration of zinc ions on the interface would lead to the growth of zinc dendrites and poor cycling performance. To address these challenges, we developed a fluorinated solid‐state‐electrolyte interface layer composed of Ca5(PO4)3F/Zn3(PO4)2 via an in situ ion exchange strategy to guide zinc‐ion oriented deposition and fast zinc ion migration on the anode during cycling. The introduction of Ca5(PO4)3F (FAP) can increase the nucleation sites of zinc ions and guide the oriented deposition of zinc ions along the (002) crystal plane, while the in situ formation of Zn3(PO4)2 during cycling can accelerate the migration of zinc ions. Benefited from our design, the assembled Zn//V2O5 ⋅ H2O batteries based on FAP‐protected Zn anode (FAP‐Zn) achieve a higher capacity retention of 84 % (220 mAh g−1) than that of bare‐Zn based batteries, which have a capacity retention of 23 % (97 mAh g−1) at 3.0 A g−1 after 800 cycles. This work provides a new solution for the rational design and development of the solid‐state electrolyte interface layer to achieve high‐performance zinc‐ion batteries. [ABSTRACT FROM AUTHOR]

Aqueous zinc ion batteries are gaining popularity due to their high energy density and environmental friendliness. However, random deposition of zinc ions on the anode and sluggish migration of zinc ions on the interface would lead to the growth of zinc dendrites and poor cycling performance. To address these challenges, we developed a fluorinated solid‐state‐electrolyte interface layer composed of Ca5(PO4)3F/Zn3(PO4)2 via an in situ ion exchange strategy to guide zinc‐ion oriented deposition and fast zinc ion migration on the anode during cycling. The introduction of Ca5(PO4)3F (FAP) can increase the nucleation sites of zinc ions and guide the oriented deposition of zinc ions along the (002) crystal plane, while the in situ formation of Zn3(PO4)2 during cycling can accelerate the migration of zinc ions. Benefited from our design, the assembled Zn//V2O5 ⋅ H2O batteries based on FAP‐protected Zn anode (FAP‐Zn) achieve a higher capacity retention of 84 % (220 mAh g−1) than that of bare‐Zn based batteries, which have a capacity retention of 23 % (97 mAh g−1) at 3.0 A g−1 after 800 cycles. This work provides a new solution for the rational design and development of the solid‐state electrolyte interface layer to achieve high‐performance zinc‐ion batteries. [ABSTRACT FROM AUTHOR]

Severe land shortage causes a higher demand for domestic and foreign land‐intensive products. As a result, resource utilization, and related environmental issues, will increase in urban areas. To this respect, the analysis of the impact of environmental regulation on urban land use efficiency helps to identify potential points for interventions designed to ensure sustainable land use. This study first introduces a theoretical framework to investigate the micro‐transmission mechanism of environmental regulation on urban land use efficiency. Our profit decision‐making model concludes that the impact of environmental regulation on urban land use efficiency is influenced by changes in the industrial structure. Empirically, our preliminary analysis suggests that in addition to population density, both formal and informal environmental regulation can promote urban land use efficiency, with a significant spatial heterogeneity across the sample regions. Further, this study shows a remarkable double‐threshold relationship between formal environmental regulation and urban land use efficiency in China. We clarify and confirm that environmental regulation promoted urban land use efficiency only when regulation intensity was higher than 0.8612. Environmental regulation increased urban land use efficiency in high‐level industrial rationalization areas, whereas it had the opposite effect in low‐level ones. Furthermore, there was a clear marginal diminishing effect of the impact of environmental regulation on urban land use efficiency when the optimization of the industrial structure was set as a threshold variable. [ABSTRACT FROM AUTHOR]

Seasonal influenza continues to impose a substantial healthcare and economic burden in the United States each year. This study assessed influenza vaccination rates among the uninsured population, determined the need for free flu vaccines, and analyzed associations of vaccination status with access, beliefs, and sociodemographic factors. Stony Brook Outreach and Medical Education (SB HOME) free clinic offers free flu vaccinations to uninsured patients over the age of 18 living in Suffolk County, New York. All patients visiting SB HOME between October 2018 and February 2019 were offered a 10-min anonymous survey assessing demographic characteristics, self-evaluation of health status, vaccination status during the 2017–2018 and 2018–2019 flu seasons, willingness to obtain a free flu vaccine, and beliefs and barriers surrounding flu vaccines. Analysis consisted of descriptive statistics, paired t tests, and χ2 tests using a significance threshold of p < 0.05. A total of 102 participants were surveyed, 80% of whom identified as Hispanic/Latino. The majority of participants expressed positive attitudes towards the influenza vaccine. Despite these positive attitudes, 72% reported not receiving the influenza vaccination during the 2017–2018 flu season, the commonly cited reasons being fear of getting sick from the flu vaccine, high cost, and not knowing where to get the vaccine. During the 2018–2019 flu season 60% of participants elected to receive a free flu shot at SB HOME, and participants with positive attitudes towards flu vaccines were more likely to accept the vaccine when offered at no cost. Fear of getting sick from the flu vaccine remained the most common reason for participants declining a free flu vaccine. Only 17% of participants would seek vaccination at the market price of $30, compared to the 76% who would if the vaccine was offered for free. Our study highlights the need for convenient and affordable access to the flu vaccine among uninsured populations, who despite recognizing the benefits of receiving the flu vaccine are unable to overcome certain barriers. Elucidating and targeting barriers specific to uninsured populations at the local community level may improve public health strategies centered on increasing vaccination rates. [ABSTRACT FROM AUTHOR]

The reaction tolerates various functional groups. [ABSTRACT FROM AUTHOR]

The article presents abstracts on geological topics which include the origin and structure of zircon in metamorphic rocks, the role of fluids during processes involving the continental crust, and geochemical characteristics of granites found in the Dabie Mountains, China.

Abstract: Detailed field and petrological studies on the South Altyn Tagh in the last decade show that high-pressure (HP) to ultrahigh-pressure (UHP) metamorphic rocks are mainly exposed at Jianggalesayi and Qingshuiquan in the west, and at Yinggelisayi in the middle of the terrane. The South Altyn Tagh UHP rocks occur as lensoid blocks in granitic gneiss, paragneiss and marble and include eclogite, kyanite-garnet-bearing pelitic gneiss, magnesite-bearing garnet lherzolite, K-feldspar-bearing garnet clinopyroxenite and garnet-bearing granitic gneiss. Zircon U–Pb SHRIMP and LA-ICP-MS dating, combined with CL and trace element analysis yield geochronological data for different South Altyn Tagh HP/UHP rocks as follows: metamorphic ages of 493±4 and 499±27Ma for the Jianggalesayi eclogite and its country rock respectively, 509±12, 489±8 and 487±10Ma for Yinggelisayi magnesite-bearing garnet lherzolite, K-feldspar-bearing garnet clinopyroxenite and garnet-bearing granitic gneiss, and 475±4 and 486±5Ma for Qingshuiquan garnet clinopyroxenite and kyanite-bearing garnet-biotite gneiss. Magmatic protolith ages of eclogite, garnet lherzolite, garnet clinopyroxenite and garnet-bearing granitic gneiss are 754±9, 844±9, 821±27 and 842±18Ma, respectively. Metamorphic ages of these rocks are consistent within errors, indicating that the South Altyn Tagh HP/UHP rocks were formed during 475–509Ma; these are 20–80Ma older than dated North Qaidam HP/UHP rocks (420–457Ma). The occurrence of possible stishovite in pelitic gneiss and the older HP/UHP metamorphic ages suggest that the South Altyn Tagh belt may not necessarily be a western extension of the North Qaidam HP/UHP metamorphic belt, offset along the Altyn Tagh strike-slip fault. [Copyright &y& Elsevier]

The article presents the decarboxylative sulfonylation of cinnamic acids along with sulfonylhydrazides under transition-metal-free conditions.

[Display omitted] • Magmatism formed during the initial stage (ca. 480Ma) and advanced stage (ca. 450Ma) of exhumation of subducted continental crust have been recognized in South Altyn western China. • Two stages of magmatism exhibits evidence for the partial melting of subducted continental crust during differential exhumation process of South Altyn in Palaeozoic. The early Palaeozoic continental subduction–collisional belt in South Altyn (SA) western China distributes a large amount of (ultra)-high-pressure ((U)HP) metamorphic and granitic rocks associated with subduction, collision, and exhumation. In this study, four granitic rocks were collected from Bashenwake located in eastern SA. The ages of the garnet-bearing alkali-feldspar granite (GAFG), garnet-bearing granitic gneiss (GGG), alkali-feldspar granite (AFG), and syenogranite (SG) are 458.0 ± 4.1, 483.0 ± 4.1, 450.0 ± 2.4, and 482.0 ± 4.9 Ma, respectively. Whole-rock major and trace elements and Sr–Nd–Pb isotope, and zircon Hf isotope compositions for all samples exhibit characteristics of a continental crustal source. Based on partial melting modeling, the source temperature of the GGG, GAFG, AFG and SG was concluded as 750–780 °C, 730–760 °C, 730–770 °C and ca. 800 °C, respectively. The source pressure was estimated as ca. 0.8 GPa for the GGG, GAFG and AFG, and ca. 1.2 GPa for SG. Combined with studies on (U)HP metamorphic rocks in SA, this study reveals that GGG is formed by metamorphism while SG is formed from partial melting of upper crustal rocks heated by upwelling mantle during the initial stage of exhumation (ca. 480 Ma) of subducted continental crust in SA. During further stage of exhumation of the subducted continental crust at ca. 450 Ma, the GAFG and AFG were formed from partial melting of GGG as a result of decreased pressure and further mantle upwelling. Consequently, the exhumation age of subducted continental crust in eastern SA is ca. 30 Myr earlier than that in western SA. Thus, the geochronology and petrogenesis of four granitic samples in this study exhibit one of very few evidence for partial melting of subducted continental crust during the exhumation and also provide magmatism exhibits evidence for the differential exhumation model of eastern SA in Palaeozoic. [ABSTRACT FROM AUTHOR]

The North Qinling orogenic belt is an important component of Qinling composite orogen in Central China. High-pressure and ultra-high pressure (HP-UHP) rocks occur as lenses or layers surrounded by gneissic rocks in the northern, central, and southern Qinling Complex of the North Qinling belt, considered to have formed through deep continental subduction. The magmatic protoliths of the HP-UHP metamorphic rocks show formation ages (ca. 800 Ma), geochemical characteristics, and Pb-Nd isotopic compositions similar to those of the Neoproterozoic igneous rocks of the South Qinling belt. Continental materials of the South Qinling belt were dragged down to mantle depths by the Shangdan oceanic crust subducted and subjected to HP-UHP metamorphism at ca. 500 Ma. The Erlangping (and Kuanping) backarc basin formed in response to subduction of the Shangdan ocean and might have developed into a limited small ocean basin at ca. 500 Ma. The HP-UHP rocks yielded retrograde metamorphic ages of ca. 470–450 Ma and ca. 420–400 Ma. These ages are identical to the age of magmatic events in the North Qinling HP-UHP belt at ~ 500 Ma, ~ 450 Ma and ~ 420 Ma, related to deep subduction/collision, slab-breakoff and crustal thinning during post-collisional extension. The dominant ca. 500–400 Ma ages of detrital zircons from the Liuling Group of the South Qinling belt match well with those from the three stages of magmatic rocks and HP-UHP rocks in the Qinling Complex. This correlation suggests that the magmatic rocks and HP-UHP metamorphic rocks in the North Qinling belt initially exhumed to the surface, eroded and were then deposited in the Liuling basin in a post-orogenic extensional setting during middle to late Devonian. New evidence suggests that the Qinling Complex is a tectonic complex rather than a uniform stratigraphic unit or a microcontinent as previously believed, and is mainly composed of the exhumed HP-UHP metamorphic rocks, deep subduction- exhumation-related magmatic rocks and the early Neoproterozoic granites together with the host rocks from the over-riding plate at an active continental margin. The early Paleozoic tectonic history of the NQB includes oceanic slab subduction and formation of arc, backarc spreading, continental deep subduction, arc-continent collision, break off, and multi-stage exhumation of the deep subducted slab, as well as extension and thinning and associated erosion and deposition. [ABSTRACT FROM AUTHOR]

Microglia are active players in inflammation, but also have important supporting roles in CNS maintenance and function, including modulation of neuronal activity. We previously observed an increase in the frequency of excitatory postsynaptic current in organotypic brain slices after depletion of microglia using clodronate. Here, we describe that local hippocampal depletion of microglia by clodronate alters performance in tests of spatial memory and sociability. Global depletion of microglia by high-dose oral administration of a Csf1R inhibitor transiently altered spatial memory but produced no change in sociability behavior. Microglia depletion and behavior effects were both reversible, consistent with a dynamic role for microglia in the regulation of such behaviors. [ABSTRACT FROM AUTHOR]

Exsolution microstructures in minerals of rocks from orogenic belts played an important role in recognition of ultrahigh-pressure (UHP) metamorphism in their host rocks by defining the subduction depth and improving our understanding of the dynamics during the subduction and exhumation of UHP rocks. However, it is a challenging scientific topic to distinguish the 'exsolution microstructures' from the 'non-exsolution microstructures' and decipher their geological implications. This paper describes the subtle differences between the 'exsolution microstructures' and the 'non-exsolution microstructures' and summarizes the progress in studies of exolution microstructures from UHP rocks and mantle rocks of ultra-deep origin. We emphasize distinguishing the 'exsolution microstructures' from the 'non-exsolution microstructures' based on their geometric topotaxy and chemistry. In order to decipher correctly the exsolution microstructures, it is crucial to understand the changes of chemistry and habits of host minerals with pressure and temperature. Therefore, it is important to combine observations of exsolution microstructure in natural rocks with experimental results at high pressure and temperature and results of micro-scale analyses. Such studies will improve our understanding of the UHP metamorphism and cast new lights on solid geoscience issues such as deep subduction of continental crusts and crust-mantle interactions. [ABSTRACT FROM AUTHOR]

Cathodoluminescence (CL) and mineral inclusions investigations show that zircons from Yinggelisayi UHP metamorphosed granitoid gneiss in Altyn Tagh exhibit core-mantle-rim internal texture with magmatic residual core, the metamorphic overgrowth mantle and the late stage rim. SHRIMP 206pb/238U ages of 5 spots from the mantles vary from 484±11 to 491±12 Ma with Th/U ratios from 0.01 to 0.03, yielding a weighted average age of 487±10 Ma (2σ) as the age of the UHP metamorphosed granitoid gneiss. The 206pb/238U ages from the oscillatory zoned cores range from 809±19 to 885±21 Ma with Th/U ratios ranging from 0.42 to 0.83, which are interpreted as the crystallization age of the protolith of the granitoid gneiss. The metamorphic age (487±10 Ma) of the UHP metamorphosed granitoid gneiss, well consistent with the peak metamorphic age (about 500 Ma) of the UHP eclogite with crystallization age of the protolith between 809±19 and 885±21 Ma at Jianggelisayi in western Altyn Tagh, indicates the existence of a UHPM belt along the south margin of the Altyn Tagh as a result of deep subduction during Early Paleozoic age of previously existing continental crust. [ABSTRACT FROM AUTHOR]

Reports on magnesite-bearing garnet lherzolite from the Altyn Tagh near the Jianggelasayi River. Formation of a high-pressure to ultrahighpressure metamorphic belt; How parageneses of minerals from magnesite-bearing garnet Iherzolite show the rock evolved a multi-stage metamorphism; Production of Grt+Ol+Opx+Cpx±Mgs, in which Al[sub 2]O[sub 3] content of Opx is very low in the peak-stage metamorphism; Calculation of the P-T condition; Implication from exsolution rods of clinopyroxene and rutile in the Grt and magnesite rimed by dolomite and orthopyroxene; Discussion of geological studies, isotopic dating, and the discovery of coesite inclusions in zircon separates from felsic gneiss from the northern margin of the Qaidam Basin; Presence of a long UHP metamorphic belt in northwest China.

Removal of nuclei in lens fiber cells is required for organelle-free zone (OFZ) formation during lens development. Defect in degradation of nuclear DNA leads to cataract formation. DNase2β degrades nuclear DNA of lens fiber cells during lens differentiation in mouse. Hsf4 is the principal heat shock transcription factor in lens and facilitates the lens differentiation. Knockout of Hsf4 in mouse and zebrafish resulted in lens developmental defect that was characterized by retaining of nuclei in lens fiber cells. In previous in vitro studies, we found that Hsf4 promoted DNase2β expression in human and mouse lens epithelial cells. In this study, it was found that, instead of DNase2β, DNase1l1l is uniquely expressed in zebrafish lens and was absent in Hsf4−/− zebrafish lens. Using CRISPR-Cas9 technology, a DNase1l1l knockout zebrafish line was constructed, which developed cataract. Deletion of DNase1l1l totally abrogated lens primary and secondary fiber cell denucleation process, whereas had little effect on the clearance of other organelles. The transcriptional regulation of DNase1l1l was dramatically impaired in Hsf4−/− zebrafish lens. Rescue of DNase1l1l mRNA into Hsf4−/− zebrafish embryos alleviated its defect in lens fiber cell denucleation. Our results in vivo demonstrated that DNase1l1l is the primary DNase responsible for nuclear DNA degradation in lens fiber cells, and Hsf4 can transcriptionally activate DNase1l1l expression in zebrafish. • DNase1l1l uniquely expressed in zebrafish lens. • DNase1l1−/− zebrafish displayed lens denucleation defect and developed cataract. • HSF4 transcriptionally activated DNase1l1l expression in zebrafish lens. • Rescue of DNase1l1l mRNA alleviated lens denucleation defect in HSF4−/− zebrafish. [ABSTRACT FROM AUTHOR]

Germline mutations in heat shock factor 4 (HSF4) cause congenital cataracts. Previously, we have shown that HSF4 is involved in regulating lysosomal pH in mouse lens epithelial cell in vitro. However, the underlying mechanism remains unclear. HSF4-deficient mouse lens epithelial cell lines and zebrafish were used in this study. Immunoblotting and quantitative RT-PCR were used for expression analysis. The protein-protein interactions were tested with GST-pull downs. The lysosomes were fractioned by ultracentrifugation. HSF4 deficiency or knock down of αB-crystallin elevates lysosomal pH and increases the ubiquitination and degradation of ATP6V1A by the proteasome. αB-crystallin localizes partially in the lysosome and interacts solely with the ATP6V1A protein of the V1 complex of V-ATPase. Furthermore, αB-crystallin can co-precipitate with mTORC1 and ATP6V1A in GST pull down assays. Inhibition of mTORC1 by rapamycin or siRNA can lead to dissociation of αB-crystallin from the ATP6V1A and mTORC1complex, shortening the half-life of ATP6V1A and increasing the lysosomal pH. Mutation of ATP6V1A/S441A (the predicted mTOR phosphorylation site) reduces its association with αB-crystallin. In the zebrafish model, HSF4 deficiency reduces αB-crystallin expression and elevates the lysosomal pH in lens tissues. HSF4 regulates lysosomal acidification by controlling the association of αB-crystallin with ATP6V1A and mTOR and regulating ATP6V1A protein stabilization. This study uncovers a novel function of αB-crystallin, demonstrating that αB-crystallin can regulate lysosomal ATP6V1A protein stabilization by complexing to ATP6V1A and mTOR. This highlights a novel mechanism by which HSF4 regulates the proteolytic process of organelles during lens development. • Germline mutations in HSF4 gene causes congenital cataracts failing in fiber cell differentiation. • Deficiency of HSF4 down regulates alpha B-crystallin resulting in elevating lysosomal pH. • Alpha B-crystallin associates with and regulates ATP6V1A protein stabilization. • mTOR is involved in regulating the association of alpha B-crystallina and ATP6V1A. [ABSTRACT FROM AUTHOR]