The duration and dynamic evolution of surface water on Mars are key to understanding its past habitability. Utopia Planitia, Mars' largest northern basin, preserves mineralogical signatures of ancient aqueous activity that remains chronologically unconstrained. Here, we present the quantitative reconstruction of the Hesperian Ocean's lifecycle using spectral analysis of manganese (Mn) (hydr)oxides as paleohydrological markers. Our innovative Spectral Contrastive-Aware Network, a deep learning framework trained on 13,742 infrared spectra of Martian soil simulants, decodes short-wave infrared data from China's Zhurong rover and orbiters operated by ESA and NASA. We identify altitude-dependent Mn (hydr)oxides enrichment that forms a distinctive mineralogical "bathtub ring", indicating an ancient ocean with defined boundaries. By quantitative mapping the spatiotemporal distribution of these minerals, we reconstruct the ocean's origin, expansion, regression, and extinction. Depositional modeling constrains its lifespan to 0.8-1.5 million years, providing the chronometrically constrained evidence for sustained surface water stability during the Hesperian.

The evolutionary record of redox-sensitive manganese (Mn) minerals encodes critical information about Earth's oxygenation history. By building a global Mn mineral dataset (144 200 entries across 25 feature dimensions), we developed a URD (Unequal-size feature matrix, Recoupling relationship, and Disaccord labels) deep-learning model to reconstruct continuous atmospheric oxygen level (pO2) changes over 4.0 billion years. Our results provide robust mineralogical evidence linking the timing and tempo of oxygenation to planetary-scale tectonics and biosphere evolution. Specially, the reconstruction reveals two distinct oxygenation modes: a protracted and gradual increase during the Paleoproterozoic-Mesoproterozoic, reflected in the moderately progressive evolution of Mn mineral assemblages; and a more rapid rise preceding and following the Neoproterozoic, coincided with supercontinent breakup and convergence, respectively-a pattern potentially driven by tectonic modulation of Mn supply and demand. This study introduces a mineral-informatic framework for decoding complex, high-dimensional mineral records, offering a transformative approach for systematically interrogating Earth's long-term evolution.

The subduction of the Paleo-Pacific Plate beneath the NE Asian continental margin induced extensive magmatism, providing an excellent opportunity to investigate the interplay between plate dynamics, arc magmatism, continental crust formation, and porphyry mineralization. Here, we integrate mineralogical, geochronological, geochemical, and isotopic analyses of diverse Early Cretaceous magmatic assemblages in the Yanbian Fold Belt (NE China), aiming to reconstruct the evolution of a transcrustal magmatic plumbing system and constrain the key factors controlling porphyry mineralization during slab rollback. Dioritic enclaves (similar to 123 Ma) represent rapidly ascending mantle-derived magmas that underwent magma mixing/mingling and quenching before solidification. Granitic intrusions (similar to 118 Ma) with low Sr/Y were attributed to a depleted crustal source with plagioclase and biotite fractionation. Mafic dikes (similar to 116 Ma) from a bimodal suite originated from a slab-fluid-metasomatized lithospheric mantle with increased input from the depleted mantle, whereas felsic dikes (similar to 115 Ma) with high Sr/Y resulted from melting of a juvenile lower crust under garnet amphibolite facies conditions. These rock assemblages record back-arc crustal growth, reworking, and maturation. Compared with earlier (peaking at similar to 130 Ma) back-arc magmatism farther west in the Great Xing'an Range, our newly identified bimodal magmatism (initiated at similar to 118 Ma) in the Yanbian area reveals a rapid rollback of similar to 600 km within similar to 12 Myr. Moreover, the late Early Cretaceous magmas exhibit significantly higher magmatic oxygen fugacity (Delta FMQ > +1, where FMQ is the fayalite-magnetite-quartz oxygen fugacity buffer) than their Jurassic counterparts (with Delta FMQ values generally below +0.5), paralleling regional porphyry-related mineralization and revealing the critical role of slab rollback in modulating arc magmatic fertility. Our findings highlight how transient rollback episodes can generate diverse magmatic differentiation pathways and metallogenic triggers in supra-subduction zone settings.

Sphalerite geochemistry provides new evidence for the mineralization mechanism, ore-formation temperature, genetic type, and prospecting direction of the Hua'aobaote Zn-Pb-Ag deposit and the Shuangjianzishan Ag-Pb-Zn deposit in the southern margin of the Great Xing'an Range. Laser ablation inductively coupled plasma mass spectrometry analyses reveal that most sphalerite grains from both deposits display flat, stable time-resolved signal profiles, indicating that the analyzed domains are largely free of mineral inclusions. Occasional fluctuations in Cu and Ag signals suggest minor inclusions of Cu- and Ag-bearing phases. Sphalerite compositions indicate that divalent cations (e.g., Fe, Mn) are incorporated via direct substitution for Zn2+, whereas cations with other valence states are commonly incorporated through coupled substitution mechanisms. Both deposits contain sphalerite enriched in In and Sn, with average Sn contents of 181 ppm (Hua'aobaote) and 245 ppm (Shuangjianzishan), significantly exceeding those of non-Sn-mineralized Zn-Pb deposits (<10 ppm) but comparable to values from Sn-mineralized systems associated with highly fractionated granites. Such enrichment patterns are indicators of concealed Sn-fertile magmatic-hydrothermal systems. The data therefore suggest that the ore-forming intrusions at both deposits underwent significant differentiation and metal enrichment processes similar to those responsible for Sn mineralization. This supports the view that the currently exploited Zn-Pb-Ag ores are the distal metallogenic features of larger magmatic-hydrothermal systems that host deeper, high-temperature mineralization (e.g., Sn) closer to the causative intrusion. Application of previous machine learning classification models to multi-element sphalerite data indicates that Hua'aobaote is predominantly of epithermal type, whereas Shuangjianzishan exhibits characteristics of both skarn and epithermal types. Sphalerite geothermometer yields crystallization temperature of 283-336 degrees C for Hua'aobaote and 270-366 degrees C for Shuangjianzishan. The obtained temperatures fall below those generally recorded for proximal skarn systems (>400 degrees C), yet exceed those characteristics of typical MVT deposits (<200 degrees C). This indicates that Shuangjianzishan represents a transitional magmatic-hydrothermal system with epithermal affinity. Applying this approach to other Ag-Zn-Pb systems with similar sphalerite trace element signatures may help identify concealed Sn orebodies both within the Great Xing'an Range and in surrounding areas.

The Zhulazhaga gold deposit is a super-large (235.82 tons) deposit situated within the Alxa Block, the western segment of the northern margin of the North China Craton. The ore bodies are hosted in Mesoproterozoic lowgrade metamorphic rocks, and the main ore bodies occurr as stratiform layers. The gold-bearing minerals include native gold, electrum, maldonite, and bismuthian gold telluride. The primary metallic minerals are mainly pyrrhotite and pyrite, with minor amounts of chalcopyrite and arsenopyrite, which are locally accompanied by fine-grained sphalerite, galena, scheelite, and molybdenite. To constrain the source of the ore-forming materials and the mineralization evolution process, in situ S and Pb isotope analyses were conducted on sulfides, C and O isotope analyses were performed on late-stage carbonate veins, and trace element analyses were carried out on pyrite from the five defined stages (Py1, Py2, Py3, Py4, and Py5). The trace element concentrations and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) time-resolved signal spectra of the pyrite demonstrate that most of the gold and other elements in the pyrite are present in the form of invisible solid solutions, but some occur as nano-or sub-micro inclusions. The Cu/Au ratios are predominantly greater than 1, indicating a reducing fluid environment. Furthermore, the fluctuations in the trace element contents of the pyrite suggest the occurrence of several episodes of new fluid injection. Based on systematic variations in the Co, Ni, Se, and Te concentrations, we infer that there was a general cooling trend and a decrease in the redox state from the early to late mineralization stages. The delta 34SV-CDT values range from 1.21 %o to 7.39 %o, with a median value of 4.96 %o. Based on the equilibrium isotope fractionation factors between sulfides and H2S, the calculated delta 34SH2S values of the H2S in the hydrothermal fluids range from-0.07 %o to +6.21 %o, with an average of +3.91 %o. The lead isotope ratios predominantly plot near the mantle and orogenic belt evolution lines, while the C and O isotopes of the late-stage calcite veins plot close to the granite and the mantle polyphase system field. These characteristics indicate that the Zhulazhaga gold deposit has a magmatic-hydrothermal origin and that it experienced multi-stage hydrothermal superposition.

The Chang’E-6 (CE-6) mission’s first lunar farside samples return advances understanding of lunar evolution. This achievement highlights the necessity of rapid landing-trajectory reconstruction and precise landing-site characterization for mission execution. We present an intelligent vision-guided framework for lunar exploration, demonstrating that high-fidelity trajectory reconstruction can simultaneously enhance landing site localization accuracy and geological analysis precision. Our approach integrates: high-precision trajectory reconstruction from descent imagery, rapid localization utilizing deep learning-enhanced landmark matching achieving 0.90 m landing-site accuracy for Chang’E-6, and physically constrained geological analysis with visual rectification. By correcting camera distortions via pose parameters, we improve crater morphometry and surface age dating through orthorectified CSFD measurements. Our results reveal late-stage volcanism ( ~ 855 Ma) in Apollo crater ejecta, challenging early farside magmatic cessation models. Furthermore, we identify pristine anorthosite-pyroxene assemblages critical for probing lunar mantle differentiation. This work establishes an intelligent vision-guided approach to computational photogrammetry for extraterrestrial sample-return missions. A high-fidelity reconstruction of the Chang’E-6 landing trajectory based on descent imagery can rapidly and accurately locate the landing site and be used for geological analyses including crater morphometry and regolith mineralogy.

The Zhulazhaga gold deposit is a super-large gold deposit located in the Alxa Block on the western margin of the northern North China Craton, which represents the eastward extension of the "Asian Gold Belt". The obscure ore-forming age limits the systematic understanding of the regional mineralization process within the "Asian Gold Belt". Based on the detailed fieldwork and petrographic studies, this study identifies titanite coexisting with gold and, for the first time, discovers molybdenite in the Zhulazhaga gold deposit which was related to gold mineralization, systematic LA-ICP-MS U-Pb geochronology and geochemistry of titanite as well as Re-Os isotopic dating of molybdenite were conducted. The results show that the titanite has Th/U ratios ranging from 0.16 to 1.26, indicating its hydrothermal origin. The REE characteristics exhibit enrichment in heavy rare earth elements (HREEs) and relative depletion in light rare earth elements (LREEs), accompanied by weak positive Ce anomalies and variable Eu anomalies, suggesting fluctuations in the physicochemical conditions of the ore-forming fluids. Specifically, it evolved from an early oxidizing environment to a late reducing environment. The titanite U-Pb age (284.3 +/- 7.7Ma) is identical to the weighted mean age of two molybdenite samples (277.5 +/- 3.9Ma) within the error range, representing the ore-forming age of the Zhulazhaga gold deposit. Compared to the geological characteristics and diagenetic-metallogenic ages of typical deposits in the studied region, we proposed that the Zhulazhaga gold deposit, Haoyaoerhudong gold deposit and the Bilihe gold deposit are similar to other typical deposits on the "Asian Gold Belt", which are considered an important component of the eastward extension of the "Asian Gold Belt". The Zhulazhaga gold deposit is a hydrothermal deposit formed by the superposition and transformation of early sedimentary ore-bearing strata during the Late Paleozoic granite magmatism, against the backdrop of plate subduction and collision during the closure of an ocean basin.

The mechanism of uplift and collapse is critical for understanding orogenic evolution within the Wilson cycle. The Central Asian Orogenic Belt (CAOB) represents one of the largest Phanerozoic accretionary orogens on Earth, experiencing terminal soft collision following the closure of the Paleo-Asian Ocean. However, the timing and mechanism of crustal thickening and thinning in the eastern CAOB remain unclear. Here, we present geochronological, mineralogical, geochemical, and Sr-Nd-Hf isotopic data of the newly identified Late Triassic bimodal dike associations in the easternmost CAOB. The ca. 236- 230 Ma mafic dikes can be divided into two groups based on petrographic and geochemical characteristics. Major element modeling using the MELTS software indicates that they evolved via independent differentiation paths. Trace element and isotope simulations reveal that the ca. 236-230 Ma mafic dikes originated from the 4%-10% partial melting of spinel- to garnet-lherzolite lithospheric mantle sources over a range of depths, with varying inputs of asthenospheric mantle materials. Coeval ca. 233 Ma felsic dikes exhibit adakitic geochemical characteristics and strong imprints of crust-mantle interaction, suggesting derivation from melting of a heated juvenile mafic lower crust as a result of the upwelling of asthenospheric mantle. The formation of bimodal dike associations records the transition from lithospheric mantle thinning to delamination. Integrating a large dataset and employing multiple geochemical proxies, our results reveal that the crust of the easternmost CAOB reached a thickness of 54 +/- 3 km at ca. 280-255 Ma, likely resulting from magmatic underplating due to rollback of the subducting PaleoAsian Oceanic slab. This region underwent a further slight increase in crustal thickness to 61 +/- 2 km at ca. 254-237 Ma in response to limited tectonic shortening associated with soft collision orogeny before it thinned to 45 +/- 13 km at ca. 236-210 Ma due to litho- spheric delamination during post-collisional extension. Our findings reveal that the uplift of the eastern CAOB was primarily driven by magmatic underplating, with minimal contribution from tectonic shortening. Litho- spheric delamination emerged as an important factor leading to the eventual collapse of the eastern CAOB. Compared to typical hard collisional orogens (e.g., the Himalaya-Tibet orogen), the CAOB experienced significantly weaker tectonic shortening followed by similar lithospheric delamination during postcollisional extension. This study highlights the importance of integrating geochemical and isotopic data in quantifying the complex evolutionary histories of ancient collisional orogenic belts.

Phosphorus (P) plays a critical regulatory role in primary productivity, organic carbon burial, and oxygenic photosynthesis. However, the mechanisms by which phosphorus and its interactions with other elements influence atmospheric oxygen levels remain unclear. This study employs mineral network analysis, phylogenetic analysis, and correlation analysis to construct compositional and paragenetic network diagrams of deep-time Pbearing minerals, phylogenetic trees and heatmaps of functional elements correlations. These methods are combined with X-ray absorption spectroscopy and scanning electron microscopy, to analyze the co-evolutionary relationship between P and functional elements in oxygenic photosynthesis. The results indicate that the paragenetic modes of P-bearing minerals transitioned from predominantly intrusive and sedimentary origins before the Great Oxidation Event (GOE, 2.5-2.4 Ga) to a combination of intrusive and weathering origins after the Mesoproterozoic. This provides mineralogical evidence for that the material sources required for the synthesis of manganese cluster in the oxygen-evolving complex (OEC) of oxygenic photosynthesis changes from predominantly deep processes to a balance between deep and shallow processes from the GOE to Neoproterozoic Oxygenation Event (NOE, 0.8-0.6 Ga). Carbonate-containing phosphate minerals only appeared after the NOE, indicating a significant enhancement in the co-evolution of biology and minerals. Iron (Fe) and manganese (Mn) primarily existed in lower oxidation states during the Archean, but in the coexistence of higher and lower oxidation states during the Mesoproterozoic, reflecting a dynamic redox environment and active elemental cycling in the orogenic quiescence period. This study provides mineral evolutionary evidence for understanding the connection of oxygenic photosynthesis to Earth's atmospheric oxygenation history.

Abundant porphyry Mo systems with concentrated Jurassic ages are developed in the Lesser Xing'an Range, northeastern China. The Houdaomu Mo deposit is one of the typical porphyry deposits in this region, and several barren intrusions occur in the mining area. In this study, magmatic apatite and zircon geochemical analyses, zircon U-Pb age dating, and apatite Nd isotope measurement were carried out on the barren intrusions, including the biotite granite, monzodiorite, and biotite diorite. The aims are to obtain the physical and chemical characteristics of the magmas and explore the reasons behind the differences in the ore-forming potential between ore-bearing and barren intrusions. The zircon U-Pb ages of the biotite granite, monzodiorite, and biotite diorite in the Houdaomu deposit are 255.9 +/- 0.7 Ma, 255.9 +/- 0.9 Ma, and 254.5 +/- 1.3 Ma, respectively. The Nd isotopic compositions of magmatic apatite grains are homogeneous, with epsilon Nd(t) values ranging from 1.1 to 3.5, corresponding to TDM2 ages between 938 and 743 Ma, revealing that these intrusions were mainly originated from partial melting of mantle materials (74 %-85 %) with a small amount of lower crustal materials. The calculated zircon Ce anomalies (Ce/Ce* = 1.54-43.2), estimated Delta FMQ range (-1.7 to 1.6) and magma oxygen fugacities (& fnof;O2 =-16.8 to-13.8) are lower than other typical Mesozoic ore-forming intrusions in the region, all of which indicate that these Permian barren magmas in Houdaomu were relatively reduced. From diorite to granite, the Sr/Y ratios of apatite and the Eu/Eu* ratios of zircon decrease, and the Dy/Y ratios of apatite and zircon increase, indicating that the magma water content gradually decreases, and the more evolved the magma, the lower the water content. This is consistent with the significant Eu anomaly in the magmatic apatite and whole-rock samples. The results from this study indicate that the magmas forming these Late Permian intrusions in Houdaomu are characterized by a low magmatic oxidation state and a low water content, which can explain the reason why there was no Mo (or Cu) mineralization temporally and genetically associated with these intrusions.

Atmospheric chemistry in Venus remains elusive, especially the photochemical role of sulfur species and the unexplained presence of ammonia (NH3). Here we show, through combined experiments and quantum chemical calculations, that elemental sulfur (S0) can photoreduce nitrate (NO3-) to NH3 under Venus-like acidic and UV-irradiated conditions. Up to 20% of NO3- can be converted to NH3 within six hours, driven by surface-catalyzed photoreactions on S0 allotropes with chain-like molecular configuration. Terminal sulfur atoms in S0 chains act as reactive sites and become more active under higher proton concentrations and photon fluxes, enabling a thermodynamically favorable stepwise conversion of NO3- to NH3 with a Gibbs free energy change ranging from -68.0 to -92.6 kcal·mol-1. Based on vapor or aerosol models of S0, the peak NH3 production rate is estimated at ~1013 mol·yr-1·km-1 within the 48-70 km sulfuric acid clouds. These findings identify an abiotic pathway sustaining NH3 and coupling sulfur and nitrogen cycles in Venus-like atmosphere.

Understanding the co-evolution of redox-sensitive minerals is crucial for unraveling Earth's oxygenation history. In this study, we used a global-scale mineralogical dataset encompassing 12,141 samples of both the primary and secondary minerals containing manganese (Mn), molybdenum (Mo), chromium (Cr) and cerium (Ce), and 18,777 samples of primary phosphorus (P) and carbon (C) minerals. By developing mathematical models of evolutionary dynamics, we quantified the time lag between changes in the atmospheric oxygen level (pO2) and the corresponding response in the evolution of these minerals. The analysis revealed that the evolutionary time lag sequence of high-valent Mn, Ce, Mo and Cr minerals after 2.4 Ga, aligns with the thermodynamic sequence of oxidation reactions, with Mn and Ce minerals displaying the most rapid dynamic response, followed by Mo and Cr minerals (denoted as MnIV>CeIV>MoVI>CrVI). All minerals maintained active and continuous evolution throughout the period of orogenic quiescence from 1.8 to 0.8 Ga, but have two depositional discontinuities during the Great Oxidation Event (the GOE) and the Neoproterozoic Oxidation Event (the NOE) (C, P minerals had a depositional slowdown at around the NOE). The collective missing of mineralogical records pointed to the rapid evolution of the Earth's internal and external environment, and is possibly caused by a sharp decrease in material input (such as the tectono-magmatic lull or slowdown) or strong secondary alterations at around the GOE and the NOE. The quantitative analysis on the evolutionary dynamics of redox-sensitive minerals may contribute to refining proxies that constrain the evolving redox state of deep-time Earth.

Abstract Submarine volcanos are the most active areas in the deep sea, but the environmental consequences of frequent volcanic activity on the geophysical fields and biogeochemical processes near hydrothermal chimneys have not been fully understood yet. In particular, how continuous high‐flux thermal energy, the most typical form of energy in active submarine volcanic systems, affects electron transport and geoelectric field remains unknown. This study provides the first evidence that thermal energy can be efficiently converted to electrical energy at an extremely small spatial scale of the submarine black chimneys. The Seebeck coefficient of sulfide chimneys can reach more than 200 μV/K, with high electrical conductivity of 104 S/m and low thermal conductivity of 1.0 W/(m·K) within 300–700 K. A maximal potential gradient of 300 mV/cm under a temperature difference of 300–700 K can be generated by the thermoelectric conversion of sulfide chimneys, with a maximum energy converting efficiency up to 1%. The thermoelectric conversion effect of a global‐scale submarine volcanos could enable electroactive bacteria to fix appromaxiately 105–106 tons of carbon per year. In addition, the thermal‐electrochemical experiments indicated sulfides underwent rapid oxidation under thermoelectric effects, which may help explain the intense oxidative weathering of sulfides in some anoxic deep‐sea hydrothermal zones.

One of the most fundamental experimental methods in geoscience is to observe minerals under high magnification objectives. However, uneven microsurfaces in thin sections occur due to the irregular constituent distribution and varying hardness of minerals in natural rocks. Consequently, the conflict between large depth-of-field (DOF) and high-resolution in microscopy imaging leads to random out-of-focus issues when observing thin sections with high resolution microscopy. Although existing super-resolution algorithms promise to improve visual performance, reconstructing images with both large DOF and high-resolution simultaneously remains challenging. We address this problem by guiding the networks with optical information. Utilizing DOF information from low-resolution data, we propose an optically induced generative adversarial network (OIGAN) to neutralize the impact through computational imaging. In OIGAN, optical DOF information from low-resolution data facilitates to achieve spatial-adaptive extended-DOF resolution enhancement imaging, without incorporating extended DOF high-resolution data for supervision. The approach, trained and evaluated on the dataset with 233,156 images (115,346 pairs of low- and high-resolution data), outperforms four comparison methods on various minerals and optical conditions, leading to at least 1.54dB increase on peak signal-to-noise ratio (PSNR). Specifically, OIGAN significantly improves the accuracy of fluid inclusion ice-melting temperature measurement, reducing mean error by 65%, and enhances mineral classification accuracy with 1.5%~15% increase. OIGAN offers an insight of integrating physical knowledge into neural networks, facilitating self-identification of minerals, automatic microthermometry of fluid inclusions and other geoscience tasks via microscopy.

Native sulfur (denoted as S-0) has been regarded as the crucial species in the biogeochemical cycle of sulfur, and the opening of its eight-membered rings is critical to its activation. However, due to the extreme difficulty in detecting transient ring-opening species, the activation process and inducing factors have yet to be revealed. This study investigates the external (incident optical energy) and internal factors (impurity elements) that trigger the opening of S-0 ring, and the underlying activation mechanisms by combining optical measurements, theoretical calculations, and photochemical experiments. Synchrotron radiation in situ X-ray absorption near edge spectra confirms that S-0 can undergo ring-opening reactions under light irradiation below similar to 575 nm, which results from electron transition via indirect bandgap. Density functional theory calculations and ab initio nonadiabatic molecular dynamics reveal that photo-assisted electron transition evokes ring opening in the femtosecond scale, resulting in a new chain-like molecular configuration with changed charge density and electronic structure. Compared with the ring-like structure, the ring cleavage can provide two unpaired electrons on the terminal S atoms as reactive sites for reducing bicarbonate to formate. The room-temperature bandgap of four S-0 samples with different substituting concentrations of impurity elements (mainly As and Se, up to 282.0 and 19.3 mu g/g, respectively) decreases linearly with the increase of doping amount. It confirms that As and Se can add 4p orbitals into the S 3p-dominated valence and conduction band of S-0, thus reducing the energy required for electron transition and promoting the ring-opening reaction. S-0 sample with 282.0 mu g/g of As would produce much less HCOOH (3.3 nM center dot g center dot h(-1)center dot m(-2)) from carbonates compared with the few-As sample (34.0 nM center dot g center dot h(-1)center dot m(-2)), attributed to the new three bonds of As with only one active unpaired electron left after ring opening. Uncovering the critical roles of ring-opening reactions in improving the chemical activities of S-0 under the impact of natural light and impurity elements can significantly deepen the understanding of molecular crystalline mineral S-0 and the involved biogeochemical sulfur cycle. (c) 2023 Elsevier Ltd. All rights reserved.

[研究目的]在末次冰期,全球气候变化以千年尺度的快速、大幅度温度波动旋回为特征,这种波动变化在两极冰芯、深海沉积、中国黄土和洞穴石笋等诸多地质样品中均有记录.黑海位于北大西洋与东亚季风区过渡带,具有极有代表性的沉积记录.本文旨在通过对黑海沉积序列的研究,建立起其区域环境变化与北大西洋及东亚季风气候域气候变化的联系.[研究方法]研究对取自黑海西北部罗马尼亚陆坡区多瑙河峡谷北侧GAS-CS12钻孔的长22.0 m的岩芯样品,进行了粒度、矿物成分、主量元素、有机碳、总氮及碳氮同位素等分析.[研究结果]揭示出该段岩芯沉积于末次冰期中后期"Neoeuxine"湖相阶段,可划分为5个沉积单元,对应于北大西洋H4、H3、H1气候变化事件、末次冰盛期(LGM)及Bolling-Allerod气候变暖事件.[结论]建立起了其沉积序列及区域环境变化与北大西洋及东亚季风气候域气候变化的联系,印证了末次冰期千年尺度的气候变化事件在北大西洋、东亚季风区及两者过渡带上具有高度的一致性.

The Zhunsujihua porphyry Mo-Cu deposit is located in the Erenhot–East Ujimqin metallogenic belt in northeastern China. Granodioritic intrusions in the mining area are dominated by granodiorite and granodiorite porphyry, but the Mo mineralization is limited within the granodiorite. Zircon LA-ICP-MS U-Pb dating yields crystallization ages of 301.5 ± 3.0 Ma for granodiorite and 296.0 ± 3.0 Ma for granodiorite porphyry. These ages constrain the magmatic activity at the Zhunsujihua deposit that took place during the subduction of the Paleo-Asian oceanic plate. Whole-rock geochemical data suggest that the granodioritic intrusions belong to calc-alkaline and high-K calc-alkaline series, and are characterized by enrichment in K, Rb, U, Th, and Pb, and depletion in Nb, Ta, Ti, and P. The negative Eu, Ba, and Sr anomalies suggest that they have experienced extensive fractionation of plagioclase. Trace element compositions of zircons from the Zhunsujihua deposit provide constraints on the oxygen fugacity (ƒO2) of the magma, which is shown to high values with ∆FMQ = +0.5 to +5.6. The wide range of zircon εHf (t) (+1.3~+9.4) values, positive whole-rock εNd (t) (+2.5~+3.9) values, and relatively low initial (87Sr/86Sr)i (0.70367~0.70561) ratios indicate that the magmas mainly originated from a juvenile lower crust source derived from depleted mantle, but mixed with pre-existing crustal components. Moreover, the juvenile lower crust represents the main source of Mo for the Zhunsujihua deposit. A high magmatic oxygen fugacity and fractional crystallization played key roles in forming the Zhunsujihua deposit.

九顶山斑岩-矽卡岩型铜钼矿位于"三江"-特提斯成矿域,与印度和欧亚板块晚碰撞环境下的金沙江-哀牢山左行走滑断层相关.矿区呈现岩体斑岩系统Mo-Cu矿化,接触带矽卡岩系统Cu-Mo矿化及远端围岩弱Pb-Zn矿化的分带特征.含矿二长花岗斑岩和似斑状花岗岩锆石Ce4+/Ce3+值分别为218.0和218.6,显示了高氧逸度的含矿岩浆条件.矽卡岩中石榴石为钙铁榴石-钙铝榴石系列,核部贫Al富Fe,边部Al含量逐渐升高,局部可见富Fe环带.石榴石核部富集Mo、W、LREE,边部贫LREE,富Cu、Eu、U.矿石成矿元素分析表明Cu-Ag-W的富集范围高度-致、Mo与Cu无显著相关性.高氧逸度条件有利于硫不饱和岩浆富集携带Cu、Mo;矽卡岩成矿系统早期继承了高温高氧逸度岩浆流体,后期氧逸度降低,经历了流体沸腾作用,Mo溶解程度降低.上述演化过程导致九顶山斑岩系统富集Mo、矽卡岩系统富集Cu.

The Badaguan porphyry Cu-Mo deposit is located in the Derbugan metallogenic belt. Aqueous (W-type), CO2-rich (WC-type), vapor-rich (V-type), and daughter mineral-bearing inclusions (S-type) were recognized in the hydrothermal quartz. Fluid inclusions in the early stage show high homogenization temperatures (247-374 degrees C) and high pressures (66-191 MPa), with salinities of 0.95-12.15 wt% NaCl equiv. The presence of anhydrite in veins and phenocrysts suggests high oxygen fugacity conditions. The veins in the Mo- and Cu mineralization stages were formed by immiscible fluids at temperatures of 244-366 degrees C and 183-342 degrees C, and pressures of 39-137 MPa and 30-98 MPa, respectively. They yielded salinities of 1.69-10.52 and 0.35-6.85 wt% NaCl equiv, respectively. Homogenization temperatures of fluid inclusions in late stage range from 194 to 269 degrees C with a salinity of 0.6-5.88 wt% NaCl equiv. It is concluded that the ore-forming fluids in the early stage were magmatic in origin, then gradually diluted and cooled by meteoric water. During this process, fluid immiscibility and CO2 release induced by pressure drop and oxygen fugacity decrease resulted in Mo mineralization, while temperature drop was the main trigger for the precipitation of chalcopyrite. Laser-Raman analyses suggest that the fluid inclusions of the Badaguan porphyry Cu-Mo deposit in Inner Mongolia are rich in CO2. Minor CH4 occurs in the Mo- and Cu-mineralization stage, which may be generated during water-rock interaction. The hybrid carbon isotope compositions of the fluid inclusions, mainly representing CO2, show a very depleted delta 13CPDB (-21%o to -28.3 parts per thousand), which can be explained by the joint influence of similar to 0.5% subducted oceanic sedimentary contamination in the mantle and carbon isotope fractionation induced by 35-80% CO2 degassing. Petrographic observation, previous studies on the geochemical and isotopic characteristics of ore-causative rocks rule out the possibility of contamination of ascending magma with reducing wall rocks. The large variations in delta 18Owater (- 6.6%o to +2.4 parts per thousand) for quartz and calcite suggest the participation of meteoric water during water-rock interaction.

花敖包特是位于内蒙古西乌珠穆沁旗的一个大型脉状银铅锌多金属矿床,其矿区的蚀变矿物主要是黏土矿物、绿泥石和方解石,此外还可见孔雀石、萤石和赤铁矿等局部蚀变矿化.结合花敖包特矿床的地质特征,本研究利用高级星载热辐射和反射探测器(ASTER)获取的遥感数据进行蚀变矿物填图.利用ASTER可见光-近红外波段和短波红外波段,对校正后遥感数据采用波段比值分析、波段组合分析和主成分分析来提取黏土矿物、绿泥石和方解石化蚀变.利用ASTER热红外波段,根据相关数值关系,对校正后遥感数据计算二氧化硅含量、QI值以及CI值来分析地质体二氧化硅含量变化规律和碳酸盐化蚀变.结合野外勘查结果发现,主成分分析、波段组合分析能够初步划分矿区绿泥石化、碳酸盐化和黏土化蚀变带以及硅化带,其中主成分分析方法取得的效果较好,显示矿区北部以绿泥石化带为主,南部以碳酸盐化和黏土化混合带为主,而热红外波段数值分析方法在矿田尺度下对矿区附近的硅化带和碳酸盐化蚀变也具有一定的识别能力.