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Gradient maturation experiment on hairs implies taphonomic changes in fossil hairs

Science China earth Sciences 2025年第1期68卷 62-73页

作者： Xin LI Yibo ZHOU Tao ZHAO Xingjian HE Yanhong PAN State Key laboratory for Mineral Deposits Research Center for Critical Earth Material Cycling Centre for Research and Education on Biological Evolution and Environment and Frontiers Science School of Earth Sciences and Engineering Nanjing University Institute of Palaeontology Yunnan Key Laboratory of Earth System Science Yunnan Key Laboratory for PalaeobiologyYunnan University

Mammalian hair, as a key feature related to endothermy, physical protection, and camouflage, has a long geohistorical record that dates back even to the Mesozoic. However, the limited information on the taphonomy of hair hinders the understanding of its evolutionary significance in deep time. To address this, we conducted taphonomic experiments to simulate the transformation process of black hair. The changes in the morphological structure, microscopic characteristics, and chemical composition of hair during the simulated fossilization process were documented by scanning electron microscopy, Fourier transform infrared(FTIR) spectroscopy, and Raman spectroscopy. Our results revealed that damage to the morphology of hair began at a mild temperature(150–175°C), and hair transformed into a fluid-like mass at a relatively high temperature(200°C). In addition, the morphological structure of melanosomes had relatively greater preservation potential than keratins did, and the microscopic features of melanosomes were persistently stable. The Raman and FTIR spectra indicated that the characteristic melanin and keratin peaks changed as the temperature increased. Although the chemical signals were not lost completely, the variations in the characteristic amide bands in the FTIR spectra indicate that the keratins severely degraded at high temperatures(>200°C), whereas the characteristic melanin bands in the Raman spectra suggested that melanin signals were still recognizable, even at high temperatures(>200°C). These results were confirmed by principal component analysis(PCA) and principal component analysis linear discriminant analysis(PCA–LDA). In addition, the Raman signals of all the samples in the simulated experiments were distinguished from the signals of common geological carbonaceous materials(humic acid), which suggested that Raman spectroscopy can be used to detect melanin in fossils.

关键词： Mammalian hair Melanin Keratin Fossilization Experimental taphonomy

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The composition of magmatic-hydrothermal fluids and their related metal mineralization

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Science China earth Sciences 2025年第1期68卷 208-225页

作者： Qihai SHU Jun DENG State Key laboratory of Geological Processes and Mineral Resources School of Earth Sciences and Resources China University of Geosciences Frontiers Science Center for Deep-time Digital earth China University of Geosciences

Magmatic hydrothermal deposits are important sources of many bulk, precious, and rare metals, and have attracted interest from both academic and industrial communities. However, it is still unclear if the major enrichment of the ore-forming metals occurs in the parental magma source region, during the magma evolution, or after the fluid exsolution. Fluid inclusions trapped in hydrothermal minerals crystallized in the early, high-temperature stage before metal precipitation record information close to that of the initially exsolved magmatic fluids, which are helpful in revealing whether the metals have been already significantly enriched prior to the hydrothermal stage. In this study, available compositional data of such early-stage fluid inclusions from magmatic hydrothermal systems globally have been compiled. The results indicate that the concentrations of Cu,Sn, and W respectively from the Cu-, Sn-, and W-mineralized fluids are significantly higher than the hydrothermal systems that do not produce ores with the corresponding metals. This suggests that Cu, Sn, and W could have already been enriched in the magma source and/or magma evolution stage. The Mo concentrations show no difference between Mo-mineralized and Mobarren fluid systems, indicating no significant pre-enrichment in the source region or during the magma evolution. This also implies that an efficient collection of Mo from a large volume of magmas is required to account for the formation of a large Mo deposit. Almost all the hydrothermal fluids contain high concentrations of Fe and Zn-Pb, but only a few of them eventually form Fe or Zn-Pb deposits, reflecting an important role of the hydrothermal evolution process on the selective metal *** above results indicate that different metals are enriched in different stages of a magmatic hydrothermal system, and that the major roles played in the formation of a deposit vary with the metal types. In addition to the metal concentrations in the o

关键词： Magmatic hydrothermal deposits Fluid inclusions LA-ICP-MS Metal enrichment Mineralization mechanism

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Halogen composition and heterogeneity in the continental lithospheric mantle

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Science China earth Sciences 2025年第1期68卷 310-314页

作者： Chunfei CHEN State Key laboratory of Geological Processes and Mineral Resources School of Earth Sciences China University of Geosciences

1. Introduction Halogens, including fluorine(F), chlorine(Cl), bromine(Br), and iodine(I), are highly mobile and water-soluble elements that can become significantly enriched in melts and fluids. In fluids and melts, halogens react with nearly all metals and readily form complexes with metal cations, significantly influencing the distribution of metal elements between different phases. Therefore, halogens play a crucial role in the migration, enrichment, and mineralization of key metals in the lithosphere(Weis et al., 2012; Liu et al., 2024).

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Formation and evolution of supercritical geofluid

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Science China earth Sciences 2025年第1期68卷 39-51页

作者： Huaiwei NI Yilin XIAO Xiaolin XIONG Xiandong LIU Chunxiao GAO Yi-Xiang CHEN Yunguo LI Wan-Cai LI Xuan GUO Yang-Yang WANG Dong-Bo TAN Li ZHANG State Key laboratory of Lithospheric and Environmental Coevolution University of Science and Technology of China Deep Space Exploration laboratory/School of earth and Space Sciences University of Science and Technology of China Guangzhou Institute of Geochemistry Chinese Academy of Sciences School of earth Sciences and Engineering Nanjing University State Key Lab of Superhard Materials Jilin University

In this work, we provide a comprehensive review on the formation, evolution, properties, and effects of supercritical geofluid. In earth's interior, enhanced miscibility between H2O and silicate by the addition of special components or by the increase of pressure and temperature gives rise to supercritical geofluid with a significant amount of both H2O and silicate *** formation of supercritical geofluid in magmatic-hydrothermal systems, typified by pegmatite system, is governed by meltfluid critical curve. The formation of supercritical geofluid in metamorphic systems, typified by subducted slab, is governed by the second critical end point. Experimental results suggest that the presence of boron and fluorine in pegmatite system makes it possible to form supercritical geofluid at crustal depths, but the release of supercritical geofluid from subducted slab is withheld until almost 100 km depth. A major presence of both H2O and depolymerized structural units（monomers, dimers, etc.） endows supercritical geofluid with unique physical properties including low density, low elastic moduli, low viscosity, high diffusivity,and high electrical conductivity. Supercritical geofluid can effectively mobilize a variety of elements even including high field strength elements and heavy rare earth elements. The chemical signatures of supercritical geofluid can be inherited by metasomatized mantle and mantle-derived melts, and this could give an explanation of the oxidation of arc magmas. Phase separation of supercritical geofluid through the mechanism of spinodal decomposition leads to formation of a melt network. Multiphase fluid inclusions recovered from subduction zone rocks and pegmatites are possible relics of supercritical geofluid. Supercritical geofluid can cause electrical anomaly and low seismic velocity near the top of subducted slab, and can be linked with intermediate-focus earthquakes. Supercritical geofluid may have played a crucial role in the formation of pe

关键词： Supercritical geofluid Miscibility Subduction zone Pegmatite

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Crustal magma oxidation state and endowments in porphyry copper deposits

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Science China earth Sciences 2025年第1期68卷 226-236页

作者： Yumin ai Massimo CHIARADIA Chao WU Huayong CHEN Key laboratory of Mineralogy and Metallogeny Guangzhou Institute of Geochemistry Chinese Academy of Sciences University of Chinese Academy of Sciences Department of earth Sciences University of Geneva Guangdong Provincial Key laboratory of Mineral Physics and Materials

Porphyry copper deposits（PCDs） supply the majority of the world's copper（Cu） as well as significant amounts of molybdenum（Mo） and gold（Au）. The formation of these deposits is controlled by a variety of geological factors, among which the magmatic oxidation is one of the focuses of current research. This study investigates the redox characteristics of arc magmas by analyzing the ratio of vanadium（V） to scandium（Sc） and its correlation with the oxygen fugacity （fO2） of magmas from arcs of various crustal thicknesses globally. We compiled an extensive dataset of published V/Sc values and studied the partition coefficients of Vand Sc between minerals and silicate melts across various magmatic environments. The results demonstrate that fractional crystallization of magnetite markedly reduces V/Sc values of the residual melt. Furthermore, magnesium number（Mg#） at the onset of magnetite fractionation is strongly positively correlated with fO2of the equilibrium magma. Based on this,the oxidation of arc magmas from different crustal thicknesses can be evaluated. The result suggests that magmas generated in crusts thicker than 20 km tend to be more oxidized with increasing crust thickness. This trend is attributed to enhanced intracrustal differentiation processes involving garnet and amphibole, particularly in mature island and continental arcs. In contrast,magmas in thinner arc crusts（<20 km）, which are significantly influenced by subducted slab materials, display higher oxidation states than most of their thicker crust counterparts. These findings suggest that both subduction dynamics and crustal thickness play a vital role in determining the oxidation state of arc magmas and, consequently, their capacity to generate PCDs. Highly oxidized, primitive arc magmas are less favorable for PCD formation due to that they tend to experience magnetite fractionation and thus sulfide saturation in the early stage of magma evolution, a process leading to copper depletion. On the contra

关键词： Magma evolution V/Sc systematics Magnetite Oxygen fugacity Porphyry copper deposits

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Boosting hydrocarbon conversion via Cu-doping induced oxygen vacancies on CeO2 in CO2 electroreduction

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Journal of Energy Chemistry 2025年第1期100卷 66-76页

作者： Lei Xue Tong Shi Chenhui Han Heng Zhang Fenrong Liu Haorun Li Yan Wang Xiaojun Gu Shanghong Zeng Inner Mongolia Key laboratory of Chemistry and Physics of Rare earth Materials School of Chemistry and Chemical Engineering Inner Mongolia University State Key laboratory of Coal Conversion Institute of Coal Chemistry Chinese Academy of Sciences Institute of Catalysis Department of Chemistry Zhejiang University National Key laboratory of Baiyunobo Rare earth Resource Research and Comprehensive Utilization Baotou Research Institute of Rare Earths

Conversion of CO2back to hydrocarbons is the most direct way of closing the“carbon cycle”,and its significance is further enlarged if this process is driven by renewable energies such as ***,precisely controlling the product selectivity towards hydrocarbons against the competitive hydrogen evolution remains challenging,especially for Cu-based ***,we report a novel defect engineering strategy,by which Cu-doping-induced oxygen vacancies on CeO2nanorods were effectively created,with adjustable vacancy/Cu *** resulting optimum catalyst shows up to 79% catalytic current density to hydrocarbons （excluding CO）,with 49% faradaic efficiency to *** and density functional theory unveil that the ratio between oxygen vacancy and Cu affects significantly the formation of*CHO and activation of H2O,which leads to the following deep hydrogenation to *** findings may spur new insights for designing and developing more controllable chemical process relevant to CO2utilization.

关键词： Nanorods

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Solar cycles during the seventeenth century revealed by equatorial aurora records

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earth and Planetary Physics 2025年第1期9卷 182-187页

作者： Yong Wei LiMei Yan Key laboratory of earth and Planetary Physics Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China College of earth and Planetary Sciences University of Chinese Academy of SciencesBeijing 100049China

Solar cycles are fundamental to astrophysics,space exploration,technological infrastructure,and earth's climate.A better understanding of these cycles and their history can aid in risk mitigation on earth,while also deepening our knowledge of stellar physics and solar system *** the solar cycles between 1600 and 1700-especially the post-1645 Maunder Minimum,characterized by significantly reduced solar activity-poses challenges to existing solar activity *** study utilizes a new red equatorial auroral catalog from ancient Korean texts to establish solar cycle patterns from 1623 to ***,a further reevaluation of the solar cycles between 1610 and 1755 identified a total of 13 cycles,diverging from the widely accepted record of 12 cycles during that *** research enhances our understanding of historical solar activity,and underscores the importance of integrating diverse historical sources into modern analyses.

关键词： solar cycle Maunder Minimum solar activity red equatorial aurora West Pacific geomagnetic anomaly

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Economic effect of China's carbon neutrality target under shared socioeconomic pathways

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Science China earth Sciences 2025年第1期68卷 142-157页

作者： Zemiao LIU Xianjin HUANG Xinxian QI School of Geography and Ocean Science Nanjing University Key laboratory of Carbon Neutrality and Territory Optimization Ministry of Natural Resources Frontiers Science Center for Critical earth Material Cycling Nanjing University

Economic feasibility is crucial for achieving the carbon neutrality target. However, current integrated assessments often underestimate the economic impacts of mitigation policies due to the lack of consideration of their economic benefits. This study integrates a warming-labour productivity model with a typical integrated assessment model using shared socioeconomic pathways. It simulates China's economic development and carbon emission levels under both baseline and carbon-neutral policy scenarios, evaluating the economic costs and benefits of emission reduction policies aimed at achieving carbon neutrality. These findings reveal the following:(1) The economic costs of emission reduction policies are projected to peak between 2050 and 2060, ranging from 0.41% to 9.37% of total GDP in the baseline scenario, primarily due to increased energy prices and R&D investments. These costs are expected to decline rapidly after 2070.(2) China's carbon-neutral policies will mitigate global warming, with the economic benefits of mitigation projected to reach 5.65% to 17.24% of China's total GDP by 2100.(3) Lowcarbon scenarios SSP1 and SSP4 could significantly reduce initial economic costs and advance the onset of net economic gains to 2060. This integrated assessment confirms that China's carbon neutrality target offers substantial net economic benefits in the long term. To minimize initial economic costs, efforts should focus on enhancing consumption-side transitions, upgrading lowcarbon technologies, and adopting new energy sources.

关键词： Climate change China Carbon neutrality Economic effects Policy

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Nitrogen addition promotes soil carbon accumulation globally

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Science China Life Sciences 2025年第1期68卷 284-293页

作者： Xuemei Yang Suhui Ma Erhan Huang Danhua Zhang Guoping Chen Jiangling Zhu Chengjun Ji Biao Zhu Lingli Liu Jingyun Fang Institute of Ecology College of Urban and Environmental Sciencesand Key Laboratory for Earth Surface Processes of the Ministry of EducationPeking University Ministry of Education Key laboratory for Transboundary Ecosecurity of Southwest China School of Ecology and Environmental ScienceYunnan University State Key laboratory of Vegetation and Environmental Change Institute of BotanyChinese Academy of Sciences

Soil is the largest carbon(C) reservoir in terrestrial ecosystems and plays a crucial role in regulating the global C cycle and climate *** nitrogen(N) deposition has been widely considered as a critical factor affecting soil organic carbon(SOC) storage, but its effect on SOC components with different stability remains unclear. Here, we analyzed extensive empirical data from 304 sites worldwide to investigate how SOC and its components respond to N addition. Our analysis showed that N addition led to a significant increase in bulk SOC(6.7%), with greater increases in croplands(10.6%) and forests(6.0%) compared to grasslands(2.1%). Regarding SOC components, N addition promoted the accumulation of plant-derived C(9.7%–28.5%) over microbial-derived C(0.2%), as well as labile(5.7%) over recalcitrant components(–1.2%), resulting in a shift towards increased accumulation of plant-derived labile C. Consistently, N addition led to a greater increase in particulate organic C(11.9%) than mineral-associated organic C(3.6%), suggesting that N addition promotes C accumulation across all pools, with more increase in unstable than stable pools. The responses of SOC and its components were best predicted by the N addition rate and net primary productivity. Overall, our findings suggest that N enrichment could promote the accumulation of plant-derived and non-mineral associated C and a subsequent decrease in the overall stability of soil C pool, which underscores the importance of considering the effects of N enrichment on SOC components for a better understanding of C dynamics in soils.

关键词： meta-analysis nitrogen enrichment soil organic carbon carbon accumulation carbon stability

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First observation results of Macao Science Satellite-1 on lightning-induced electron precipitation

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Science China earth Sciences 2025年第1期68卷 1-10页

作者： Yongping WANG Yixin SUN Qiugang ZONG Gaopeng LU Xudong GU Ze-Jun HU Bin LI Key laboratory for Polar Science Ministry of Natural Resources Polar Research Institute of China Institute of Space Physics and Applied Technology Peking University State Key laboratory of Lunar and Planetary Science Macau University of Science and Technology School of earth and Space Sciences University of Science and Technology of China School of Electronic Information Wuhan University

The Medium-energy Electron Spectrometers(MES) is a space-borne instrument onboard Macao Science Satellite-1(MSS-1) dedicated to monitoring the typical charged particle radiation characteristics in the satellite orbit and the process of their occurrence and development, including short bursts of lightning-induced electron precipitation(LEP).This paper presents the first results of the LEP measurements by the MSS-1.47 LEP events are identified with the routine operation for 3 months since satellite launch, all within the range of 1.5ain L-parameter), and the causative lightning discharges are definitively geo-located for these LEP *** LEP events occur within <1 s of the causative lightning and consist of 40–300 keV electrons.A preliminary observation result indicates that, with medium-energy electron detectors, MSS-1can present in-situ observations of large regions of enhanced background precipitation and reveal their fine spatiotemporal characteristics and spectral *** collaborative VLF ground-based measurements at the Great Wall Station, Antarctica also have a good correspondence with LEP measurements of *** observations also imply that lightning activity has a modulation effect on the energetic electron energy-spatial structure.

关键词： Lightning-induced electron precipitation Inner radiation belts Energetic electrons Macao Science Satellite-1

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