Search

The COVID-19 pandemic catalyzes new opportunities for CSR development, and companies in both China and the US, the two largest economies severely impacted by the pandemic, are seeking innovative ways to engage with publics on social media through CSR communication. This study draws on the care ethics theory to examine different manifestations of care values in corporations' CSR messages and their relationships with publics' behavioral and emotional engagement on social media. A quantitative content analysis of Weibo and Twitter posts from Fortune 500 companies in China (n = 30) and the United States (n = 30), respectively, revealed that companies in both countries employ multifaceted care-based CSR messages, but in distinct ways and with varying types and levels of public engagement on social media. We interpreted the differences from institutional, cultural, and relational perspectives. The results of this research add to theorizing CSR communication from a feminist ethical viewpoint and with contextualized interpretations. Our findings also guide post-pandemic CSR communication development, particularly relevant to public relations practitioners in the Chinese and US markets. [ABSTRACT FROM AUTHOR]

The study on the origin of quartz and silica in Xuanwei Formation coal in Northwest Yunnan, China, is helpful to understand the relationship between quartz and silica and the high incidence of lung cancer from the root. To address these questions, the mineralogy and microscopic studies of silica in Xuanwei Formation coal were performed. The following results were obtained: (1) silica in the late Permian Xuanwei Formation coal seams originated from detrital input, early diagenesis, and late diagenesis. (2) A more significant contribution comes from early diagenesis, which contains abundant authigenic quartz and amorphous silica. (3) Quartz and silica from inorganic silicon are more symbiotic with kaolinite and from biogenic silicon with chamosite. (4) Three silica polymorphs in coal samples have been identified: opal-A (amorphous silica), opal-CT/-C (cristobalite/tridymite), and α quartz. (5) Opal-A is ubiquitous, while opal-CT/-C and α quartz are rare. (5) Opal-A is an amorphous and nontoxic ordinary silica. (6) Since the toxicity of amorphous silica and its presence in coal is an emerging topic, it should be continuously monitored. [ABSTRACT FROM AUTHOR]

This work aims to understand the distribution and migration mechanisms of U and Mo between surface sediment and water in acid mine drainage (AMD) regions near a molybdenum mining region. A series of river sediment and water samples near the Jinduicheng mining area, one of the largest deposits of molybdenite ore in Asia, were collected and analyzed. Our results indicate that: (1) The pH value of river water samples increases with distance from upstream to downstream, while the pH has poor correlation with Mo and U; (2) The content of Mo and U in the sediment are significantly higher than the background value, which suggests potential pollution; (3) The content of Mo and U in the water and sediments in the lower reaches of the Wenyu river is significantly linearly related with the distance from the mining area, suggesting that AMD is a potential source; (4) BCR analysis shows that Mo in river sediments mainly existed as the residual, while U mainly existed as the non-residual; (5) The distribution coefficient Kd(Mo) exceeds Kd(U), indicating that Mo is enriched in sediments while U is more prone to porewater. [ABSTRACT FROM AUTHOR]

The paleosedimentary environment and paleoclimate of the Neogene Guantao Formation in the Liaodong sub-uplift of Bohai Bay Basin in China, which is an important oil and gas exploration horizon, are not clear owing to the lack of quantitative analysis. The paleosedimentary environment and paleoclimate can be qualitatively or semi-quantitatively reconstructed by sedimentary geochemical indicators sensitive to the environment and climate. Based on the evaluation of whether the elements and isotopes can effectively record paleosedimentary environment and paleoclimate information or not, the paleoclimate (temperature and humidity), paleoenvironment (salinity, water depth, redox conditions), and evolution of the paleoenvironment and paleoclimate are studied by analyzing the trace elements, carbon and oxygen isotopes, strontium isotopes, whole-rock mineral compositions, and clay minerals of mudstones of the Guantao Formation in the Liaodong sub-uplift, Bohai Bay Basin. The study results show that (1) according to the trace element distribution patterns, high concentrations of continental elements (Ti, Zr, Th), clay minerals, and detrital content, the Guantao Formation is a product of proximal deposits, and the provenance mainly originates from the intermediate–acidic magmatic rocks near surrounding uplifts. (2) The paleoclimate during the sedimentation of the Guantao Formation was mainly semi-arid and semi-humid, as revealed by the Sr/Cu ratio. However, the high Rb/Sr and 87Sr/86Sr ratios demonstrate that the paleoclimate is relatively warm and humid. (3) The paleosedimentary temperature calculated by the Sr content and δ18O is roughly 30 °C, indicating that the Guantao Formation was deposited in a subtropical to tropical climate. (4) The Guantao Formation was deposited in continental freshwater according to the Li, Ni, and Sr content, Sr/Ba ratios, 87Sr/86Sr ratios, and salinity index Z. (5) The water depth of the paleoenvironment of the Guantao Formation is mainly in nearshore shallow water, reflected by the Mn/Ti ratio and calculated by the Co content, and the oxidizing condition of the paleoenvironment of the Guantao Formation, reflected by the U/Th, V/Cr, and Ni/Co ratios, is in a good coupling relationship with this environment. (6) As revealed by the variations in the geochemical data in the section, the temperature, humidity, and water depth of the Guantao Formation gradually increased from the early to late period, while the salinity gradually decreased, and the chemical weathering effect gradually increased. [ABSTRACT FROM AUTHOR]

The ophiolites along the North Qilian Orogenic Belt are considered to be fragments of ancient oceanic crusts and lithospheric mantle of the Palaeozoic North Qilian Ocean (a branch of the Proto‐Tethys). Compared with other ophiolites in this belt, the genesis of the Xiejiayao ophiolite has been poorly studied so far, making it difficult to understand the tectonic evolution of the ocean. In this study, we present new compositional and Sr‐Nd isotopic analyses of basaltic rocks from the Xiejiayao ophiolite to shed light on its petrogenesis and geodynamic background. These oceanic basalts are characterized by flat REE patterns, low elemental ratios of high‐field‐strength elements (e.g., La/Sm, Sm/Yb, La/Yb, Gd/Yb, [Th/Yb]PM) and abundant spinels, implying that they were generated via partial melting in the spinel stability field of the mantle. Their positive εNd(t) values (6.1–8.4), high Zr/Nb (43.65–79.40) as well as low Nb/Ta (10.91–15.09), Zr/Hf (34.64–39.28), and Nb/Yb (0.41–0.59) ratios further reflect that the ancient mantle had already become depleted to some extent before the onset of the Palaeozoic ocean. Additionally, basalts share many geochemical similarities (e.g., Zr, Y, Ti, and V) with both mid‐ocean ridge and island arc basalts. This supports the strong likelihood of origin in a back‐arc basin close to the suprasubduction zone for the ophiolite. Therefore, accompanied by the northward subduction of the oceanic lithosphere during the early Palaeozoic, a large‐scale back‐arc basin developed progressively in response to the back‐arc expansion. The Xiejiayao basaltic magmas were generated in the back‐arc basin via partial melting of the depleted mantle and their source was probably mixed with subducted melts/fluids from the dehydration and melting of oceanic slabs and sediments. [ABSTRACT FROM AUTHOR]

We attempt to understand the pollution characteristics and carcinogenic risk of toxic elements around Hutou Village, Xuanwei City, Yunnan Province, China. For this propose, 48 road dust samples were collected systematically, and the concentrations of Cr, Ni, Cu, Zn, As, Cd, Pb, Co, and Cr(IV) were analyzed and compared; the spatial distribution was obtained. The Igeo and EF indices and multivariate statistical analysis (CA, PCA, HACA) were carried out for source investigation, and human health risk assessment was also adopted to evaluate local non-carcinogenic and carcinogenic risks. The result showed that Cr, Ni, Cu, Cd and Co contaminations were quite serious; Zn, As, Cd, and Pb had similar distribution pattern, and Cr and Ni also shared similar distribution characteristics; Cd, Pb, Zn, and As ascribed to anthropogenic sources, while Cr and Ni originated from either anthropogenic activity or natural sources; Co and Cu originated from natural sources; the non-carcinogenic risk of Co cannot be ignored. The carcinogenic risk of Ni was considered unacceptable. Finally, an indoor coal-burning pattern was established that the high Cd and Ni inhalation and ingestion model was associated with lung cancer. [ABSTRACT FROM AUTHOR]

• Clay minerals and carbonate cementation are associated with U mineralization. • δD and δ18O values of clay minerals suggesting meteoric origin of the ore fluid. • Hydrocarbons may have played an important role in U mineralization. • H-O-C isotopes suggest a transient interface between oxidizing/reducing fluids. The Meso-Cenozoic Yili Basin in northwestern China hosts important uranium and coal resources. The uranium deposits are mainly hosted by sandstones and are characterized by clay and carbonate alterations within and surrounding the orebodies. H-O-C isotopes of clay minerals and carbonate cement in the different alteration zones of the uranium deposits in the southern margin of the Yili Basin are summarized to examine the mechanisms of uranium mineralization. The alteration zones associated with the uranium mineralization include an intensely oxidized zone, a weakly oxidized zone, a transitional (mineralization) zone, and a reduced zone. The δD and δ18O values of the parent fluids calculated from clay minerals from the different alteration zones show a linear trend that intersects the global meteoric line at a point with a δ18O V-SMOW of ca. −5‰ and a δD V-SMOW of ca. −30‰, which coincide with the upper end of the δD – δ18O trend (along the meteoric line) of formation waters in the basin, suggesting that the uranium mineralizing fluid was of meteoric origin. The general trends of decreasing δD and δ13C and increasing δ18O from the intensely oxidized zone to the reduced zone, together with the fact that calculated δD V-SMOW values of the mineralizing fluids are lower than the original meteoric fluid, and that the δ13C values of the calcite cement overlap with those of organic matter in sedimentary rocks, suggest that hydrocarbons were involved in uranium mineralization. The hydrocarbons may have been important reducing agents causing precipitation of uranium minerals. The hydrogen ion released from oxidation of the hydrocarbons may have been buffered by the formation of clay minerals, which favors co-development of clay alteration and calcite cement. Deviation of H-O-C isotopes from the general variation trends as expected from the above redox mechanism likely resulted from the dynamic nature of the redox front, which changed its position in response to hydrodynamic balance between a downward flow of uranium-bearing, oxidizing fluid and an upward flow of reductants-bearing, reducing fluid from the lower part of the basin. [ABSTRACT FROM AUTHOR]

To explore geochemical factors affecting the chronological reconstruction of a historical arsenic pollution accident in Lake Qionghai at southwest of China, heavy metals and radionuclides (210Pbexand137Cs) in two sediment cores were sampled and analyzed. Our study revealed that (1) industrialization and urbanization of Xichang since the mid-20thCentury, aggravated soil erosion in the catchment and resulted in a significant and lasting increase in the sedimentation rate of Lake Qionghai; (2) sharp arsenic peaks in two sediment cores recorded an arsenic pollution accident in 2006 in which a large amount of arsenic was discharged into the lake from a chemical plant. Arsenic peaks in sediment cores A and B were dated to 1988 ± 3.5, 2006 ± 3.1, respectively. Only the arsenic peak time in core B: 2006 ± 3.1, agreed with the real pollution accident time of 2006. Linear correlation analysis suggested that arsenic sorption by Fe/Mn minerals and organic materials in sediment core A probably changed the depth distribution of the peak and affected the accuracy of chronological reconstruction. This case study suggested that sorption of heavy metals by Fe/Mn minerals and organic materials should be assessed before the chronological reconstruction of the metal pollution accident in the lake. [ABSTRACT FROM AUTHOR]

The isotopic composition and parameters for deuterium excess of brines, which were sampled in the Sichuan Basin, show obvious regularities of distribution. The brine isotopic composition shows distinct two systems of marine and terrestrial deposits, with the Middle Triassic strata as the boundary. Brine hydrogen isotopic composition of marine deposits is lower while oxygen isotopic composition is higher than that of the SMOW, respectively, indicating that the brines were derived from seawater with different evaporating degrees at different times. From the Sinian strata, up to the Cambrian, Permian Maokou Formation and the Triassic Jialingjiang Formation, the δD values of brines tend to become relatively positive with the strata becoming younger. Brines of terrestrial deposits are considered to have been derived from precipitation and their isotopic composition is close to the globe meteoric water line (GMWL). Brines of transitional deposits between marine and terrestrial ones (the Upper Triassic Xujiahe Formation) have δD and δO values falling between the two end members of marine deposit brines and precipitation, indicating that the brines are a mixture of precipitation and vaporing seawater. Water samples from the brine-bearing strata of different ages show various deuterium excesses ( d) with an evident decreasing trend as the age of strata gets older and older. Brine-bearing strata of the Triassic Leikoupo-Jialingjiang Formation, the Permian Maokou Formation, the Cambrian and Sinian strata are all carbonate rocks which have experienced intensive water/rock reaction and the deuterium excess essentially changes with time. All brine-bearing-strata surrounding the basin or faults, as well as those brine wells exploited for resources, have been obviously influenced by the precipitation supply. Therefore, the deuterium excesses of their brines have increased to different extents, depending on the amount of involvement of meteoric water. The variation and distribution of d values of the brines from different Triassic strata are related to the embedded depth of the strata. The deuterium excesses of brines become lower with increasing burial depth of the strata. [ABSTRACT FROM AUTHOR]

Abstract: In China, soil pollution is very serious, which has jeopardized the ecology, food safety, the people''s health, and even the sustainable development of agriculture. In order to investigate the soil pollution situation, a total of 874 agricultural and non-agricultural topsoil samples were collected from Dexing area, northeast of Jiangxi Province, China. The total elemental concentrations of 17 elements (As, Hg, Mo, Cd, Cr, Zn, Cu, Mn, Ti, Pb, Fe, Ca, K, Si, Al, Mg, and Na) were determined. The geochemical background and threshold was predicted with the method of the median±median absolute deviation (MAD). The agricultural soil median concentration of trace elements was similar to that of the non-agricultural soil. In contrast to Jiangxi soil background of trace elements, the geochemical background of the study area was obviously higher. The maps of the pollution indices for As, Cd, Cr, Cu, Hg, Mn, Mo, Pb, Ti and Zn of non-agricultural soil and agricultural soils in the study area, showed that the highest level of pollution is distributed near and along the Lean River, especially in the neighboring and surrounding Dexing and Leping mining area. [Copyright &y& Elsevier]

A baseline might be used as a point of reference to monitor change from some specific data without concern for whether the baseline determination is natural or has been changed by human activity. We selected 326 sediment samples from Dexing area, South China, and analyzed for 17 chemical elements. The geochemical baseline was predicted with the method of the normalization procedure combined with the relative cumulative frequency curve. The results indicate Al was the best reference element for the normalization procedure among four potential reference elements (Al, Fe, Ti, and Mn). The baseline value range obtained from the normalization procedure method included both the regional geochemical background of the sediment and the median value of the measured contents. The median value of baselines obtained from relative cumulative frequency method was lower than that obtained from normalization procedure method. In contrast to the geochemical patterns of heavy metals in 1987, the spatial distribution of anomalies sprawled in 2004 in study area, especially for Cu, Pb, Zn, Cd, As, Fe, and Cr. [ABSTRACT FROM AUTHOR]

Presents a study on the kinetic modeling of diagenesis of Eogene Lacustrine sandstone reservoirs in the Jianghan Basin, Southeastern China. Diagenetic features identified in the sandstones; Simulation of the kinetics of fluid-mineral reactions and the concentrations of aqueous species; Result of the weak pore fluid during the early diagenetic stage; Cause of the precipitation of quartz, kaolinite and illite.

Presents a study that determined geochemical baseline models and assessed the contributions of trace elements from natural and anthropogenic sources in the Panzhihua mining area in China. Background on Panzhihua; Adoption of a normalization procedure to establish geochemical baselines; Analytical results and relevant parameters for trace metals in topsoil samples from the area.

Air pollution is becoming increasingly serious along with social and economic development in the southwest of China. The distribution characteristics of particle matter (PM) were studied in Chengdu from 2016 to 2017, and the changes of PM bearing water-soluble ions and heavy metals and the distribution of secondary ions were analyzed during the haze episode. The results showed that at different pollution levels, heavy metals were more likely to be enriched in fine particles and may be used as a tracer of primary pollution sources. The water-soluble ions in PM2.5 were mainly Sulfate-Nitrate-Ammonium (SNA) accounting for 43.02%, 24.23%, 23.50%, respectively. SO42−, NO3−, NH4+ in PM10 accounted for 34.56%, 27.43%, 19.18%, respectively. It was mainly SO42− in PM at Clean levels (PM2.5 = 0~75 μg/m3, PM10 = 0~150 μg/m3), and mainly NH4+ and NO3− at Light-Medium levels (PM2.5 = 75~150 μg/m3, PM10 = 150~350 μg/m3). At Heavy levels (PM2.5 = 150~250 μg/m3, PM10 = 350~420 μg/m3), it is mainly SO42− in PM2.5, and mainly NH4+ and NO3− in PM10. The contribution of mobile sources to the formation of haze in the study area was significant. SNA had significant contributions to the PM during the haze episode, and more attention should be paid to them in order to improve air quality. [ABSTRACT FROM AUTHOR]

The article discusses the research study conducted to examine the geologic history of the iron oxide copper gold (IOCG) deposits in Southwestern China that was associated with polymetallic mineralization. It reveals the age of magmatic rocks and metallogenic epoch and the coupling relationship between polymetallic elements. It also reveals the ore-forming process including the volcanic sedimentation, grenville orogenic event, and superimposed mineralization.

The article focuses on a research paper analyzing the platinum-group element (PGE) constraint on the origin mechanism of the Hetaoshu PGE deposit in the Xiaoguanhe Region in Panxi Area, China. The concentrations of PGE, copper and nickel in rock samples show that the ore forming elements consists of nickel and copper. It also evaluates the impact of sulfide segregation on the ore-forming process of Hetaoshu deposit.

• There was severe Cd and Cr pollution in the soil of Hutou Village. • The primary source of soil pollution was the use of coal. • Mineralogical and geochemical characteristics revealed the migration direction of the pollution. • The contents of REY and Eu in the soil were significantly higher than those in road dust. • The fractionation of LREY and HREY in the soil was more substantial than that in the road dust. This study aimed to reveal the status and source apportionment of trace element soil pollution in a village with a relatively high incidence of lung cancer in China and determine the element migration characteristics from coal to road dust and soil. To this end, 24 soil samples, 48 road dust samples (from a previous study), and 2 coal samples were collected; major element oxides, V, Cr, Co, Ni, Cu, Zn, Zr, Cd, and rare earth elements were analyzed; minerals were identified by SEM-EDX and XRD; a geoaccumulation index (I geo), Spearman's correlation analysis, provenance index (PI) and positive matrix factorization (PMF) were carried out to assess the status and source apportionment of soil pollution; and mineralogical and geochemical methods were used for provenance discrimination and migration characteristics identification. The results demonstrated that (1) the Cd and Cr pollution of the soil was severe and originated mainly from indigenous zinc smelting, agricultural activities, and the use of coal. (2) The pollution migrated from Yantang coal to the road dust to the soil through mineralogical and geochemical methods. (3) A stronger fractionation of light and heavy rare earth elements was observed in the soil than in the road dust, indicating a single pollution source in the road dust and a complex source in the soil. (4) The primary reason for the lower rare earth element values in the road dust could be physical separation by the wind. [ABSTRACT FROM AUTHOR]

Abstract: The Wenchuan earthquake with magnitude 8.0 hit Longmen Mountain on May 12, 2008. The coseismic deformation changed the slope in an instant and caused massive outbreaks of landslides and debris flows, which altered the river transport system. The seismic landslides, debris flows and subsequent heavy rainfall and flooding increased sediment discharge. Data on sediment discharge, rainfall, landslides, and debris flows were collected in this study for 1980–2010 to describe the effects of the Wenchuan earthquake and post-earthquake heavy rainfall on the increase in sediment discharge in the upper reaches of the Min River. The relationship between precipitation, sediment discharge, landslides, and debris flows before and after the Wenchuan earthquake in the upper reaches of the Min River was analyzed. The variation trends of sediment discharge in the river basin before and after the earthquake were calculated quantitatively. The research results can be summarized as follows: (1) Sediment discharge increased by approximately 30% due to coseismic uplift, coseismic landslides, and debris flows after the Wenchuan earthquake. (2) The sediment discharge caused by heavy rainfall after the earthquake was 1.75 times larger than before the earthquake. The percentage contribution of the sediment yield of debris flows induced by heavy rainfall after the earthquake to the increase in sediment discharge was 34.54%. (3) The heavy rainfall zone basically coincided with the earthquake fault zone and the seismic landslide zone. Therefore, there was a positive-feedback relationship between the increase of sediment discharge and heavy rainfall after the Wenchuan earthquake. (4) The loosening of surface materials and landslides driven by the Wenchuan earthquake resulted in an increase in sediment discharge into the river, bringing about a great disaster which will need to be addressed in the coming decades. [Copyright &y& Elsevier]

A complete and accurate set of thermodynamic data for aqueous uranium species is necessary in order to determine the toxicity of uranium in water, to predict its fate in the environment and to design possible remediation strategies for polluted environments. Comparisons of the completeness and accuracy of the thermodynamic databases for aqueous uranyl complexes involving common inorganic anions (OH−, SO 4 2−, PO 4 3−, CO 3 2−, SO 4 2−, Cl−,F−, I−, Br−) and some organic ligands have been made between a number of publicly-available thermodynamic databases (MINTEQ, LLNL, WATEQ4F, ThermoChimie, NEA-TDB, and PSI/Nagra). The results indicates that: (1) stability constants for most aqueous inorganic uranium species in the ThermoChimie, NEA-TDB, and PSI/Nagra databases are broadly similar, but ThermoChimie includes a greater number of organic uranium species; (2) ThermoChimie and two other modern developing databases (NEA-TDB, and PSI/Nagra) are recommended for calculating uranium speciation in natural/polluted waters except for those containing high concentrations of inorganic phosphate; (3) the stability constant for U(OH) 4 from the LLNL database is much greater than the values found in the other databases (by four orders of magnitude) and needs to be replaced; (4) the MINTEQ, LLNL, and WATEQ4F databases need updating for many important uranium species including Ca 2 UO 2 (CO 3) 3 , UO 2 (H 2 AsO 4) 2 and all the organic uranium species, and (5) the MINTEQ database does not include U(IV)‑bromine, U(IV)‑iodine or U(IV)-nitrate complexes, while the other databases do not include U(IV)-phosphate complexes. A case study of the water chemistry in a phosphate mining region of China, including river water from close to a fertilizer plant, indicates that the calculated uranium speciation varies greatly between the different databases. In particular, the existence and stability of the UO 2 (HPO 4) 2 2− species needs confirmation and quantification including supporting spectroscopic measurements. Although the stability of the stronger bioavailable uranyl-phosphate complexes remains uncertain, the available thermodynamic data suggests that the proportion and toxicity of most uranyl-phosphate complexes will be negligible when the pH exceeds 8.5 and the inorganic phosphate concentration (as PO 4 3−) is <2 mg/L. • Stability constants of aqueous uranium species of six thermodynamic databases available were investigated and compared. • ThermoChimie and two other databases are recommended for most waters except those with high inorganic phosphate. • Most uranyl phosphate complexes are negligible when pH exceeds 8.5 for water with phosphate (as PO 4 3–) is ≤ 2 mg/l. [ABSTRACT FROM AUTHOR]

• Neoproterozoic I- and A-type granites were identified in the Yili Block, CAOB. • Transition from syn-collision to post-collisional extension occurred at ca. 890 Ma. • Reworking controlled the early Neoproterozoic crustal evolution in the Yili Block. • The Precambrian evolution of the Yili Block is distinct from that of the Tarim Craton. The Yili Block in NW China and NE Kazakhstan is a continental fragment within the Central Asian Orogenic Belt (CAOB). We present a systematic study of whole-rock geochemistry, Sr–Nd–Hf isotopic compositions, and U–Pb geochronology of newly identified Neoproterozoic granitic plutons from the southern Yili Block to further constrain the Proterozoic evolution of microcontinents constituting the CAOB. Gneissic, augen, and mylonitized granites yield intrusion 206Pb/238U ages of 947 ± 4 Ma, 889 ± 5 Ma, and 892 ± 5 Ma, respectively. The gneissic granites display affinities to calc-alkaline, weakly peraluminous, magnesian I-type granites (Mg# = 33–34; FeOT/MgO = 3.49–3.59). The augen and mylonitized granites lie on the ferroan, calc-alkaline, highly fractionated A-type granite trend (Mg# = 11–21, FeOT/MgO = 6.52–14.58, SiO 2 > 74 wt%, 10000*Ga/Al = 2.80–3.26). The markedly enriched Sr–Nd–Hf isotopic compositions of the ca. 947 Ma magnesian I-type granites suggest a derivation from ca. 2.0 Ga MgO-rich basement rocks. The varied initial 87Sr/86Sr ratios (0.716530–0.720543), chondrite-like εHf(t) values (−2.11 to 0.72), and differentiated incompatible elements of the ca. 890 Ma A-type granites suggest a derivation from partial melting of ca. 1.8 Ga crustal sources, followed by strong fractional crystallization. The Yili Block probably constituted part of an exterior orogen that developed along the margin of the Rodinia supercontinent during the early Neoproterozoic, undergoing a tectonic transition from syn-collisional to post-collisional extension at ca. 890 Ma. This study reveals that crustal reworking played a key role in Neoproterozoic crustal evolution in the Yili Block and that this block has a tectonic affinity to the Central Tianshan Block but is distinct from the Tarim Craton. [ABSTRACT FROM AUTHOR]

Urban activity emissions have important ecological significance to bacterial communities' spatial and temporal distribution and the mechanism of bacterial community construction. The mechanism of bacterial community construction is the key to community structure and lifestyle, and the influence of this aspect has not been thoroughly studied. This study analyzed the response of bacteria in water and sediment in different seasons to urban activities in Jinsha River. The results showed that the influence of urban activities on bacterial community structure in sediment was greater than that in water. The input of pollution in different regions changed the diversity and abundance of water and sediments bacteria and promoted bacterial community reconstruction to a certain extent. Co-network analysis found that many metal-mediated species are core species within the same module and can be used to mitigate pollution caused by metal or organic pollutants due to interspecific solid interactions. Different potential pollution sources around urban rivers affect the metabolic function of bacteria in aquatic ecosystems and promote the detoxification function of bacteria in different media. The results of this study supplement our understanding of the characteristics of microbial communities in urban river systems and provide clues for understanding the maintenance mechanism of microbial diversity in multi-pollution environments., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

In this study, the core carcinogenic elements in Xuanwei Formation coal were identified. Thirty-one samples were collected based on the age-standardized mortality rate (ASMR) of lung cancer; Si, V, Cr, Co, Ni, As, Mo, Cd, Sb, Pb, and rare earth elements and yttrium (REYs) were analyzed and compared; multivariate statistical analyses (CA, PCA, and FDA) were performed; and comprehensive identification was carried out by combining multivariate statistical analyses with toxicology and mineralogy. The final results indicated that (1) the high-concentration Si, Ni, V, Cr, Co, and Cd in coal may have some potential carcinogenic risk. (2) The concentrations of Cr, Ni, As, Mo, Cd, and Pb meet the zoning characteristics of the ASMR, while the Si concentration is not completely consistent. (3) The REY distribution pattern in Longtan Formation coal is lower than that in Xuanwei Formation coal, indicating that the materials of these elements in coal are different. (5) The heatmap divides the sampling sites into two clusters and subtypes in accordance with carcinogenic zoning based on the ASMR. (6) PC1, PC2, and PC3 explain 62.629% of the total variance, identifying Co, Ni, As, Cd, Mo, Cr, and V. (7) Fisher discriminant analysis identifies Ni, Si, Cd, As, and Co based on the discriminant function. (8) Comprehensive identification reveals that Ni is the primary carcinogenic element, followed by Co, Cd, and Si in combination with toxicology. (9) The paragenesis of Si (nanoquartz), Ni, Co, and Cd is an interesting finding. In other words, carcinogenic elements Ni, Co, Cd, and Si and their paragenetic properties should receive more attention., (© 2024. The Author(s).)

Chengdu, a megacity in southwestern China, experiences severe air pollution; however, knowledge of the seasonal variation in mass concentration, extent of potentially harmful elements (PHEs) contamination, and sources caused by heavy metals remains lacking. This study adopted a weighting method to calculate the daily mass concentration of PM 1 and used ICP-MS to determine PHE concentrations. Results indicated that PM 1 mass concentration was in the range 5.44-105.91 μg/m 3 . Seasonal PM 1 mass concentration could be arranged in the following order: winter > fall > spring > summer. The concentrations of PHEs in the PM 1 sample mostly showed the same seasonal variation characteristics as mass concentration. The average concentration of each PHE decreased as follows: Cu (107.44) > Zn (81.52) > Pb (22.04) > As (8.17) > Sb (1.91) > Ni (1.87) > Cr(VI) (0.84) > Cd (0.40) > Tl (0.33) (ng/m 3 ). Enrichment factor values varied markedly from mild to anomalous enrichment. Principal component analysis revealed mainly derived from the fossil fuel combustion (55.215%).

This paper systematically studied the mass concentration levels of PM 2.5 and PM 10 and obtained the morphological characteristics and components of the particles through scanning electron microscopy (SEM-EDX) and discussed the sources of the particles. Meanwhile, the health risk was evaluated according to the mass concentration of particulate matter. The results showed that the average annual PM 2.5 and PM 10 in the eastern part of Chengdu were 101.99 μg/m 3 and 168.89 μg/m 3 , respectively, exceeding the national second-level average annual air quality standard (GB3095-2012). Both of them were the highest in winter and the lowest in summer and had a significant positive correlation. The atmospheric particles in the study area were mainly composed of fly ash particles, soot aggregates, mineral particles (sulfate mineral particles, carbonate mineral particles, etc.), which mainly came from coal burning, dust, automobile exhaust and secondary products. The results of the health risk assessment showed that the mass concentration of PM 2.5 and PM 10 in the atmosphere of the eastern part of Chengdu exceeded the IT-1 target. The average annual air quality index was 185.84, and the air quality index was level 4, classified as medium pollution. PM 10 and PM 2.5 were both excessive pollutants, and PM 10 was the primary pollutant. Relevant measures should be taken to control particulate matter sources to some extent.