The Lithosphere Structure and its Implication for Different Metallogenic Belts beneath the Eastern South China Block

The South China Block(SCB)was formed through the Neoproterozoic amalgamation of the Yangtze Block(YB),the Cathaysia Block(CB),and the accreted components of the Jiangnan orogenic belt(JNO),it is bounded by the Jiangshan–Shaoxing–Pingxiang fault(JSPF)and the Jiujiang–Shitai–Jishou fault(JSJF)(Yao et al.,2019).The SCB has undergone a series of complex geological events,including Paleozoic orogeny,Mesozoic collisions with the North China Craton(NCC)and the Indochina Block,as well as the intracontinental orogeny,leading to extensive lithospheric modifications and magmatic activities(Zhang H J et al.,2023;Fig.1).

Evolutions of sedimentary facies and palaeoenvironment and their controls on the development of source rocks in continental margin basins:A case study from the Qiongdongnan Basin,South China Sea

Hydrocarbon resources in the Qiongdongnan Basin have become an important exploration target in China.However,the development of high-quality source rocks in this basin,especially in its deep-water areas,are still not fully understood.In this study,evolutions of sedimentary facies and palaeoenvironment and their influences on the development of source rocks in diverse tectonic regions of the Qiongdongnan Basin were investigated.The results show that during the Oligocene and to Miocene periods,the sedimentary environment of this basin progressively varied from a semi-closed gulf to an open marine environment,which resulted in significant differences in palaeoenvironmental conditions of the water column for various tectonic regions of the basin.In shallow-water areas,the palaeoproductivity and reducibility successively decrease,and the hydrodynamic intensity gradually increases for the water columns of the Yacheng,Lingshui,and Sanya-Meishan strata.In deep-water areas,the water column of the Yacheng and Lingshui strata has a higher palaeoproductivity and a weaker hydrodynamic intensity than that of the Sanya-Meishan strata,while the reducibility gradually increases for the water columns of the Yacheng,Lingshui,and Sanya-Meishan strata.In general,the palaeoenvironmental conditions of the water column are the most favorable to the development of the Yacheng organic-rich source rocks.Meanwhile,the Miocene marine source rocks in the deep-water areas of the Qiongdongnan Basin may also have a certain hydrocarbon potential.The differences in the development models of source rocks in various tectonic regions of continental margin basins should be fully evaluated in the exploration and development of hydrocarbons.

Resin composition: An indicator of oil maturity as revealed by fourier transform ion cyclotron resonance mass spectrometry

A pyrolysis experiment was carried out on a Dongying Depression kerogen sample to separate the resin from the oil. Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) with a positive-ion detector was used to detect the relative proportional changes in the compounds of the resin. During the whole pyrolysis experiment, the relative ratio of resin exceed 10% of the soluble component at each temperature point. Five compounds were detected from the resin: N1, N1O1, N1O_(2), O1, and O_(2). To research the changes in the proportions of the compounds during pyrolysis clearly, these five compounds were divided into three classes: N1, N1Ox, and Ox. The N1 class has the largest proportion in resin at the beginning of the pyrolysis, while Ox class has the least proportion. And the relationship between the number and the molecular mass of three classes compound was researched. With increasing maturity, the proportion of N1 and the N1Ox class decreased rapidly, while the Ox class increased slowly. Through researching these resin compounds, it was found that an inversion in the proportions of above three compounds appeared at the end of the oil window. At the same time, we found that the DBE and carbon number of resin compounds have changed obviously during the pyrolysis: the DBE increased, while the carbon number decreased significantly. And the details of the change of each compound have been researched. This research extends our knowledge of judging the maturity of crude oil during the pyrolysis through the characteristics of compounds in resin and provides the new index based on resin for the evaluation of thermal evolution stage and hydrocarbon generation capacity of source rocks.

Rare earth element enrichment in sedimentary phosphorites formed during the Precambrian-Cambrian transition,Southwest China

Numerous sedimentary phosphorites in Southwest China were formed around the Precambrian–Cambrian transition(PC–C),including the upper Ediacaran Doushantuo Formation and lower Cambrian Gezhongwu Formation.The Gezhongwu phosphorites in Zhijin exhibit marked rare earth element(REE)enrichment(>1000 ppm),and may represent new REE resources.Although the main characteristics of the Gezhongwu phosphorites have been well constrained,the REE enrichment mechanisms remain unclear.We undertook a comparative study of three typical sedimentary phosphorites with variable REE contents formed at the PC–C transition in central Guizhou Province,Southwest China.These include sections A and B of the Doushantuo phosphorites(560±8 Ma)from the Weng’an area(i.e.,WA-A and WA-B),and the Gezhongwu phosphorites(527±24 Ma)from the Zhijin area(ZJ).The phosphorites were investigated with state-of-the-art macroscale to nanoscale analytical techniques.In contrast to the extraordinary REE enrichment in the ZJ phosphorites(average RREE=1157 ppm),the phosphorites in WA-A(average RREE=234 ppm)and WA-B(average RREE=114 ppm)are REE-poor.Elemental mapping by laser ablation–inductively coupled plasma–mass spectrometry,along with transmission electron microscopy analyses,showed the REEs in the studied phosphorites are hosted in nanoscale francolites.The 87Sr/86Sr and Y/Ho ratios of the francolite grains indicate that greater terrigenous input may have led to more REE enrichment in the WA-A than WA-B phosphorites,but this cannot explain the extraordinary REE enrichment in the ZJ phosphorites.The F/P_(2)O_(5)values of the francolite grains in the ZJ phosphorites(~0.097)are higher than those in the WA-A(~0.084)and WA-B(~0.084)phosphorites,and the grain size of the francolite in the ZJ phosphorites(~89.9 nm)is larger than those in the WA-A(~56.6 nm)and WA-B(~57.4 nm)phosphorites,indicative of more intense reworking of the ZJ than WA phosphorites during early diagenesis.A plot of Nd concentration versus Ce/Ce^(*)reveals that lower sedimentation rates characterized the ZJ phosphorites.Therefore,intense sedimentary reworking during early diagenesis resulted in more REEs being sequestered by the marine phosphates from seawater and pore waters at a lower sedimentation rate,which resulted in the extraordinary REE enrichment in the ZJ phosphorites.Our findings highlight the multiple factors that controlled formation of sedimentary phosphorites around the PC–C transition(especially the intense reworking and redox conditions of the overlying seawater),and provide further insights into REE enrichment in sedimentary phosphorites worldwide.

Chronological and Geochemical Study of the Cenozoic Potassic Felsic Igneous Rocks in Western Yunnan,SE Tibet:Implications for their Tectonic Mechanisms

Whether there is a relationship between widespread Cenozoic igneous rocks and the activated Ailao Shan-Red River shear zone(ASRR)in western Yunnan,SE Tibet,remains highly controversial.New geochronological,and geochemical data derived from Cenozoic igneous rocks both within and far from the ASRR offers answers.Although these coeval felsic rocks(36.9-33.5 Ma)are enriched in large-ion lithophile elements relative to high field strength elements,they also display some special geochemical features,such as high Y and Yb values of syenitic porphyries,which contrast with the high Sr and low Y contents of monzoporphyries and granitic porphyries.The syenitic porphyries exhibit geochemical characteristics similar to those of coeval mafic magmas,e.g.,high K 2 O,Y,and Yb contents,indicating that the former were probably generated by fractional crystallization of the latter.However,the high Sr/Y(56.1-109)monzoporphyries and granitic porphyries,combined with their low MgO,and Cr(or Ni)contents,suggest that they were mainly derived from partial melting of a thickened mafic lower crust.Given that these Cenozoic magmatic events exhibiting planar distributions occurred outside of the activation of the ASRR(31-20 Ma),then they were not controlled by the latter.Instead,they were tied to convective removal of a thickened lower lithospheric mantle in western Yunnan during the Paleogene.

Abiotic Hydrocarbons Generation Simulated by Fischer-Tropsch Synthesis under Hydrothermal Conditions in Ultradeep Basins

FTT experiments with water as a hydrogen source and three types of possible carbon sources in the subsurface(diiron nonacarbonyl,siderite and formic acid,representing CO,CO_(2)and a simple organic acid,respectively)were carried out in this study.Our experimental results showed that n-alkanes with the highest carbon number of C_(33)were produced when CO was used as a carbon source(series A);a variety of polycyclic aromatic hydrocarbons(PAHs)were detected in series B with CO_(2)as a carbon source;gaseous hydrocarbons were also detected with formic acid added(series C).The different products in the three series showed that there were different hydrocarbon generation mechanisms and reaction processes with different carbon sources.The generation of long-chain n-alkanes in series A provided experimental support for the formation of abiogenic petroleum underground,which was of significance to early membranes on the Earth.PAHs in series B provide experimental support for the possibility of an abiotic source of reduced carbon on other planets.The carbon isotopes of gaseous hydrocarbons produced by CO exhibited a partial reversed order(δ^(13)C_(1)<δ^(13)C_(2)>δ^(13)C_(3)>δ^(13)C_(4)>δ^(13)C_(5)),while the gaseous hydrocarbons produced by CO_(2)and HCOOH showed a positive order(δ^(13)C_(1)<δ^(13)C_(2)<δ^(13)C_(3)<δ^(13)C_(4)<δ^(13)C_(5)).Based on these,the alkylene mechanism and the carbonyl insertion mechanism were used to reasonably explain these characteristics.

Distribution and risk assessment of heavy metals in surface sediments of coastal mudflats on Leizhou Peninsula,China

Mudflats play a vital role in maintaining the dynamic balance between sea and land.To understand the characteristics,sources,and pollution risks of six heavy metals(As,Cd,Cr,Cu,Hg,and Pb)in the coastal mudflats on the Leizhou Peninsula,257 surface sediment samples were studied using mathematical statistics,correlation analysis,and factor analysis.The results show that the overall concentrations of these heavy metals are low although there are several high abnormal points in the local areas.The strong correlation between these heavy metals indicates that the sources of some of the metals are similar,yet their elemental combinations in different cities(counties)varied.According to the calculated enrichment factor(EF),anthropogenic activity-induced heavy metals were determined in order of decreasing influence:As,Cd,Pb,Cr,Cu,and Hg.The low EF values of Hg indicate that it does not present as a contaminant in the study area,while low values of Cr and Cu from the Lianjiang City suggest that these two metals were also attributed to natural sources.The presence of As,Cd,Cr,Cu,and Pb from the remaining cities(counties)should be influenced by anthropogenic activities.The overall potential ecological risk index indicates that the ecological risks posed by the six analyzed heavy metals to the Leizhou Peninsula mudflats,in order of decreasing risk,are Cd,As,Hg,Pb,Cu,and Cr.It is noteworthy that only Cd in Lianjiang City demonstrated substantial ecological risk.Other examined heavy metals in other cities of the study area showed slight ecological risk.

The Lithospheric Structure in the South China Block from Receiver Function: Implications for the Source of Mineral System

The South China block(SC),composed of Cathaysia(CA),Jiangnan Orogenic belt(JNB),and Yangtze block(YB),is one of the most important poly-metallic metallogenic provinces in the world(Zhang et al.,2013),containing of four famous major Mesozoic metallogenic belts,involving the Middle-Lower Yangtze Fe-Cu-Au metallogenic belt(MYMB).

Distribution and geochemical significance of trace elements in kerogens from Ediacaran–Lower Cambrian strata in South China

Some trace elements(TEs),both bio-essential and redox-sensitive,are promising tracers of Earth’s surface processes.As an essential sedimentary organic matter,kerogen may have inherited and retained the key TEs from organisms.In this study,the distribution of TEs in kerogens from two sections(Dongkanshang and Fengtan) in South China was analyzed to explore its biogeochemical significance during Ediacaran-Lower Cambrian.Compared with V and Zn,the relative concentrations of Co,Ni,Cu,and Mo were generally higher in kerogens than in the whole rocks.Enrichment of TEs in the kerogen was involved in the selective utilization of TEs by different organic precursors and the competition of sulfide in the depositional environment.The significant content of TEs in the kerogens from deep-water facies corresponded to a more negative δ^(13) Ckeras a result of the dominant taxa of chemo autotrophs with tremendous bioaccumulation potential for trace metals and the reduction conditions favorable for organic matter preservation.Furthermore,the content variations of trace elements in the kerogens coincided with the rise and fall of the Ediacaran biota,implying that the trace elements might have played an important role in early life evolution.

Solubility of water in bridgmanite

Water in Earth's mantle plays a critical role in both geodynamic and surficial habitability.Water in the upper mantle and transition zone is widely discussed,but less is known about the water in the lower mantle despite it constituting over half of Earth's mass.Understanding the water storage in Earth's lower mantle relies on comprehending the water solubility of bridgmanite,which is the most abundant mineral both in the lower mantle and throughout Earth.Nevertheless,due to limited access to the lower mantle,our understanding of water in bridgmanite mainly comes from laboratory experiments and theoretical calculations,and a huge controversy still exists.In this paper,we provide a review of the commonly employed research methods and current findings concerning the solubility of water in bridgmanite.Potential factors,such as pressure,temperature,compositions,etc.,that influence the water solubility of bridgmanite will be discussed,along with insights into future research directions.

Structural characterization and mass spectrometry fragmentation signatures of macrocyclic alkanes isolated from a Sydney Basin torbanite,Australia

Individual hydrocarbons identified to be macrocyclic alkanes in a torbanite from the Sydney Basin(Australia)were successfully isolated from its extracts using preparative gas chromatography and analyzed by NMR.Saturated cyclic structures were confirmed by single peaks in the NMR~1H and~(13)C spectra indicating single forms of H and C atoms exist in these biomarker molecules.This is consistent with the methylene unit in a ring system assignment of the macrocyclic alkanes and accounts for a formula of(CH2)n.The unusual molecular structures of these compounds are consistent with those that were identified from previous GC retention index data and co-injection with a standard supports the previous research.The mass spectral fragmentation behaviors of representative cyclic alkanes were further investigated by comparing them with the mass spectra of isolated individual macrocyclic alkanes.The characteristic fragment ions in the macrocyclic alkanes of(M–28)+and base peaks of m/z 97,111,125,etc.,can be assigned as being generated by simple a-/i-cleavage and hydrogen rearrangement.These fragmentation pathways combined with retention indices should assist in differentiating these compounds from monounsaturated alkenes and alkylated monocyclics having similar mass spectral characteristics in other geological samples.

Gas-in-Place(GIP) Variation and Main Controlling Factors for the Deep Wufeng-Longmaxi Shales in the Luzhou Area of the Southern Sichuan Basin,China

The Wufeng-Longmaxi Formation shales with burial depths > 3 500 m in the southern Sichuan Basin are believed to have large shale gas potentials.However,the reservoir properties and gasin-place(GIP) contents of these shales exhibit variations across different sublayers.In this study,a set of Wufeng-Longmaxi shales with burial depths of 4 000–4 200 m was derived from the Well Y101H2 in the Luzhou area,and the differences in geological and geochemical characteristics,porosity,water saturation and GIP content of various sublayer shales were investigated.The results indicate that the TOC content and effective porosity of the upper(LMX1-4) and lower(LMX1-3) sublayer shales of the first member of the Longmaxi Formation are better than those of the Wufeng Formation(WF) shales,which results in the LMX1-4 and LMX1-3 shales having higher GIP contents than the WF shales.The GIP contents of the LMX1-3 shales are higher than those of the LMX1-4 shales,and this is likely because the organic matter of the LMX1-3 shales had more aquatic organisms and was preserved in a stronger reductive environment,which leads to a stronger gas generation potential.In contrast to the middle-shallow LMX1-4 shales in the Sichuan Basin,the deep LMX1-4 shales in the Luzhou area have advantageous reservoir properties and GIP contents,and thus it is promising to synchronously exploit the deep LMX1-4 and LMX1-3 shales in some regions of the southern Sichuan Basin.

Contrasting oxidation states of low-Ti and high-Ti magmas control Ni-Cu sulfide and Fe-Ti oxide mineralization in Emeishan Large Igneous Province

Magmatic Ni-Cu-(PGE) sulfide and Fe-Ti oxide deposits in plume-related large igneous provinces(LIPs)are commonly related to low-Ti and high-Ti series magmas, respectively, but the major factors that control such a relationship of metallogenic types and magma compositions are unclear. Magma fOcontrols sulfur status and relative timing of Fe-Ti oxide saturation in mafic magmas, which may help clarify this issue. Taking the Emeishan LIP as a case, we calculated the magma fOof the high-Ti and low-Ti picrites based on the olivine-spinel oxygen barometer, and the partitioning of V in olivine. The obtained fOof the high-Ti series magma(FMQ + 1.1 to FMQ + 2.6) is higher than that of the low-Ti series magma(FMQ-0.5to FMQ + 0.5). The magma fOof the high-Ti and low-Ti picrites containing Fo > 90 olivine reveals that the mantle source of the high-Ti series is likely more oxidized than that of the low-Ti series. The results using the ’lambda REE’ approach show that the high-Ti series may have been derived from relatively oxidized mantle with garnet pyroxenite component. The S contents at sulfide saturation(SCSS) of the two series magmas were calculated based on liquid compositions obtained from the alpha Melts modeling, and the results show that the low-Ti series magma could easily attain the sulfide saturation as it has low fOwith S being dominantly as S. In contrast, the oxidized high-Ti series magma is difficult to attain the sulfide saturation, but could crystallize Fe-Ti oxides at magma MgO content of ~7.0 wt.%. Thus, contrasting magma fOof low-Ti and high-Ti series in plume-related LIPs may play an important role in producing two different styles of metallogeny.

Early planetary processes and light elements in iron-dominated cores

This paper discusses the latest research on the accretion and differentiation of terrestrial planets and multidisciplinary constraints on light elements in irondominated metallic cores.The classic four-stage model of terrestrial planet formation advocates slow and local accretion.Meanwhile,the pebble accretion model suggests fast accretion for planets,while the Grand Tack model provides heterogeneous accretion mechanisms.Terrestrial planets and small interstellar bodies may have experienced at least some degree of partial melting due to the three primary energy sources(i.e.,the decay of short-lived radioactive nuclides,the kinetic energy delivered by impacts,and the conversion of gravitational potential energy).Together with metal-silicate separation mechanisms,the magma ocean theory depicts the pattern of core formation in terrestrial planets.Several hypotheses have been proposed to explain the concentration of siderophile elements in the mantle,including the single-stage,continuous,and multistage core formation models,and the lateveneer model.Some light elements have been postulated in the core to account for Earth’s outer core density deficit.A plethora of constraints on the species and concentration of light elements have been put forward from the perspectives of cosmochemical and geochemical fingerprints,geophysical observations,mineral physics,numerical modeling,and theoretical prediction.Si and O may be the two leading candidates for Earth’s outer core light elements;however,it still remains an open question.S is another potential light element in Earth’s core,most likely with less than 2 wt%.Other light elements including H and C,may not exceed1 wt%in the core.Moreover,the accretion and differentiation history would provide some clues to light elements in other terrestrial planetary cores.In principle,a larger heliocentric distance corresponds to accretion from more oxidized materials,leading to a higher S concentration in the Martian core.On the contrary,Mercury is close to the Sun and has accreted from more reduced materials,resulting in more Si in the core.

Geochemistry and geochronology of multi-generation garnet:New insights on the genesis and fluid evolution of prograde skarn formation

Origin of garnet in skarn(magmatic vs.hydrothermal)and the prograde skarn fluid evolution are still controversial.Two generations of garnet(Grt1,Grt2)were identified at the Tongshankou deposit:Grt1 is anisotropic with oscillatory zoning and resorbed boundary,whilst Grt2 grew around Grt1 and formed oscillatory rims.In-situ LA-ICP-MS U-Pb dating of Grt1 and Grt2 yielded a lower intercept^(206)Pb/^(238)U age of 142.4±2.8 Ma(n=57;MSWD=1.16)and 142.3±9.6 Ma(n=60;MSWD=1.06),respectively,coeval with the ore formation and ore-related granodiorite emplacement.Positive Eu anomaly,non-CHARAC Y/Ho value and low TiO_(2)content,together with the mineral assemblages indicate that both Grtl and Grt2 have a hydrothermal origin.The existence of melt and melt-fluid inclusions in Grt1,together with similar LREE-enriched patterns to the granodiorite,further indicate that Grt1 may have formed in the magmatic-hydrothermal transition.Higher U contents and LREE-enriched patterns of Grt1 indicate that fluid I is mildly acidic pH and low fO_(2).The inner gray Grt2 rims(Grt2A)is HREE-enriched with low U contents,indicating that fluid II has nearly neutral pH and high fO_(2).The wider Y/Ho range and LREE-enriched patterns of the outer light-gray Grt2 rims(Grt2B)show that the evolved magmatic fluidⅡhad mixed with an external fluid,characterized by being mildly acidic pH and with high fO_(2)·Our results suggest that the prograde skarn-forming fluids can be multistage at Tongshankou,and the mixing of meteoric water may have been prominent in the prograde skarn stage.

Gas Generation from Coal and Coal-Measure Mudstone Source Rocks of the Xujiahe Formation in the Western Sichuan Depression,Sichuan Basin

The Triassic and Jurassic tight sandstone gas in the western Sichuan depression,Sichuan Basin has attracted much attention in recent years,and the Upper Triassic coal-bearing Xujiahe Formation is believed to be the major source rock.However,there are relatively few studies on the carbon isotopic heterogeneity of methane generated from coal-measure source rocks and the origin of the natural gases in Xinchang Gas Field is still controversial.In this study,one coal-measure mudstone sample and one coal sample of the Xujiahe Formation in western Sichuan Basin were selected for gold tube pyrolysis experiment to determine their gas generation characteristics.Geological extrapolation of gas generation and methane carbon isotope fractionation parameters reveals that the main gas generation stage of Xujiahe Formation ranges from Late Jurassic to Cretaceous in the Xinchang Gas Field.The natural gas in the 5th member of Xujiahe Formation in Xinchang Gas Field is mainly derived from the 5th member of Xujiahe Formation itself,i.e.,self-generation and self-reservoir,however,the gas in the Jurassic gas pools is mainly derived from the source rocks of the 3rd member of Xujiahe Formation rather than the 5th member of Xujiahe Formation.

Scavenging and release of REE and HFSE by Na-metasomatism in magmatic-hydrothermal systems

Exploitable or potentially exploitable deposits of critical metals,such as rare-earth(REE)and high-field-strength elements(HFSE),are commonly associated with alkaline or peralkaline igneous rocks.However,the origin,transport and concentration of these metals in peralkaline systems remains poorly understood.This study presents the results of a mineralogical and geochemical investigation of the Na-metasomatism of alkali amphiboles and clinopyroxenes from a barren peralkaline granite pluton in NE China,to assess the remobilization and redistribution of REE and HFSE during magmatic-hydrothermal evolution.Alkali amphiboles and aegirine-augites from the peralkaline granites show evolutionary trends from sodic-calcic to sodic compositions,with increasing REE and HFSE concentrations as a function of increasing Na-index[Na^(#),defined as molar Na/(Na+Ca)ratios].The Na-amphiboles(i.e.,arfvedsonite)and aegirine-augites can be subsequently altered,or breakdown,to form hydrothermal aegirine during late-or post-magmatic alteration.Representative compositions analyzed by insitu LA-ICPMS show that the primary aegirine-augites have high and variable REE(2194-3627 ppm)and HFSE(4194-16,862 ppm)contents,suggesting that these critical metals can be scavenged by alkali amphiboles and aegirine-augites.Compared to the primary aegirine-augites,the presentative early replacement aegirine(Aeg-I,Na^(#)=0.91-0.94)has notably lower REE(1484-1972)and HFSE(4351-5621)contents.In contrast,the late hydrothermal aegirine(Aeg-II,Na^(#)=0.92-0.96)has significantly lower REE(317-456 ppm)and HFSE(6.44-72.2 ppm)contents.Given that the increasing Na^(#)from aegirine-augites to hydrothermal aegirines likely resulted from Na-metasomatism,a scavenging-release model can explain the remobilization of REE and HFSE in peralkaline granitic systems.The scavenging and release of REE and HFSE by Na-metasomatism provides key insights into the genesis of globally significant REE and HFSE deposits.The high Na-index of the hydrothermal aegirine might be useful as a geochemical indicator in the exploration for these critical-metals.

‘Super-stable' interlayer organic carbon in soil clay minerals and its impact on soil carbon sequestration

Soils play a significant role in the global carbon cycle, acting as both sinks and sources of terrestrial carbon. They exert substantial influence on climate change by regulating the atmospheric concentrations of greenhouse gases, including carbon dioxide, through processes of carbon fixation and release (Lehmann et al., 2020). Soil organic carbon represents a key carbon reservoir within terrestrial ecosystems.Therefore, enhancing soil organic carbon levels is a crucial strategy for augmenting terrestrial carbon sinks and mitigating global climate change.

The use of electrokinetics promises a sustainable mining future

Moving toward a zero-carbon economy is an ambitious goal of all human beings.Utilization of various metal resources plays a central role in such a transition.Rare earth elements(REEs),especially heavy REEs(HREEs),are crucial for the development of future green and zero-carbon economies due to their irreplaceable roles in many applications of renewable energy technologies;e.g.,solar panels,wind turbines,and hybrid vehicle batteries.Ion-adsorption rare earth deposits(IADs)are the primary repositories for HREEs and supply more than 95%of the global HREE demand.1 However,current mining technologies using excessive ammonium salts have caused devastating harm to the local environment while exhibiting a low recovery rate of REEs,a long mining period,and landslide risks.Since 2018,the adoption of ammonium salt-based techniques in REE mining has been prohibited,exacerbating the scarcity of REEs that could lead to disruptions of the supply chain.Moreover,metals are currently almost exclusively extracted from their ores via physical excavation or chemical leaching.These energy-intensive and environmentally damaging techniques remain among the foremost CO_(2) emitters.The mining industry is in desperate need of a new generation of mining technology.

Unravelling biosynthesis and biodegradation potentials of microbial dark matters in hypersaline lakes

Biosynthesis and biodegradation of microorganisms critically underpin the development of biotechnology,new drugs and therapies,and environmental remediation.However,most uncultured microbial species along with their metabolic capacities in extreme environments,remain obscured.Here we unravel the metabolic potential of microbial dark matters(MDMs)in four deep-inland hypersaline lakes in Xinjiang,China.Utilizing metagenomic binning,we uncovered a rich diversity of 3030 metagenomeassembled genomes(MAGs)across 82 phyla,revealing a substantial portion,2363 MAGs,as previously unclassified at the genus level.These unknown MAGs displayed unique distribution patterns across different lakes,indicating a strong correlation with varied physicochemical conditions.Our analysis revealed an extensive array of 9635 biosynthesis gene clusters(BGCs),with a remarkable 9403 being novel,suggesting untapped biotechnological potential.Notably,some MAGs from potentially new phyla exhibited a high density of these BGCs.Beyond biosynthesis,our study also identified novel biodegradation pathways,including dehalogenation,anaerobic ammonium oxidation(Anammox),and degradation of polycyclic aromatic hydrocarbons(PAHs)and plastics,in previously unknown microbial clades.These findings significantly enrich our understanding of biosynthesis and biodegradation processes and open new avenues for biotechnological innovation,emphasizing the untapped potential of microbial diversity in hypersaline environments.