Abstract:

The Chang'e 6 (CE6) mission achieved the first sample return from the lunar farside in 2024, recovering 1 935.3 g of regolith. This study focuses on ilmenite in CE6 lunar soil breccia and basalt clasts, integrally employing characterization techniques such as scanning electron microscopy (SEM), electron probe microanalysis (EPMA), high-resolution transmission electron microscope (HRTEM), electron energy-loss spectroscopy (EELS), and three-dimensional electron diffraction (3DED) to systematically investigate the mineralogical characteristics of ilmenite with different occurrences in the CE6 lunar soil. The results indicate that ilmenite in basaltic clasts exhibits characteristics of primary magmatic origin, whereas ilmenite in breccia clasts commonly displays shock-metamorphic features such as mechanical fragmentation and impact melting. Raman spectra show no resolvable differences in peak positions or full width at half maximum (FWHM) among ilmenite grains with different occurrences. HRTEM observations reveal neither dislocation development nor amorphization, confirming the preservation of lattice integrity despite prolonged exposure to lunar surface impact processes. Compositional variations between ilmenite in basalt and breccia clasts are minor, and no significant changes in Ti or Fe valence states were detected. Notably, compared to ilmenite from basalt clasts, those from breccia clasts display relative enrichment in trace elements and a higher abundance of oxygen vacancies, which could be ascribed to shock metamorphism. These findings provide robust mineralogical evidence for the exceptional resistance of ilmenite to impact-induced structural modification and refine our understanding of its occurrence and stability within the lunar surface environment.

Abstract:

The Chang'e-5 (CE5) and Chang'e-6 (CE6) missions returned lunar regolith samples from the Procellarum KREEP Terrane (PKT) on the Moon's nearside and the South Pole-Aitken Basin (SPA) on the farside, respectively, providing invaluable materials for comparative studies of geological differences between the Moon's two hemispheres. Spinel group minerals are significant accessory phases in various lunar rocks. Owing to their complex isomorphic substitution, spinel can offer unique constraints on the petrogenesis of lunar lithologies. This study systematically investigates the petrographic and compositional characteristics of spinel grains in the Chang'e samples. In CE5 basalt samples, spinel crystals predominantly occur as inclusions in olivine grains. They evolve toward titanium-iron end member with progressive magma differentiation. Spinel in CE5 breccias and impact melt fragments generally exhibit similar features to those in basalts. In CE6 basalts, spinel grains are mainly hosted by pyroxene or occur as interstitial phase coexisting with fayalite and ilmenite, rarely found in olivine. They share a similar compositional evolution trend to CE5 basalts. Moreover, CE6 samples also contain diverse types of spinels derived from distinct sources, including Mg-suites, aggregates from lunar mantle, and impact-generated fragments with nonlunar signatures. Based on spinel compositions in basalts, thermodynamic models were conducted to constrain the parental magma compositions of CE5 and CE6 low-Ti basalts. Our results indicate that compositions of bulk basalts or melt inclusions are not appropriate proxies for the real parental magma. In addition, both the model results and the trace-element analyses of spinel samples suggest the crystallization sequences of the CE5 and CE6 basalts are different. Therefore, when reconstructing magma compositions from equilibrium melt with different lunar minerals, it is essential to consider the specific stage of magmatic evolution represented by the mineral.

Abstract:

The formation mechanism of high-valence iron oxides on the lunar surface is one of the key issues in planetary science. To reveal the formation conditions and evolutionary processes of such minerals, this study conducted detailed microstructural characterization and iron valence-state analyses of spherical magnetite particles identified in Chang'e-5 lunar soil. The results show that the particle is composed of micrometer-scale magnetite grains cemented by Si—O amorphous material lacking volatile elements such as F and Cl. Combined with its spherical morphology, internal cavity, aggregated grain texture, and Si—O-rich amorphous material between grains, these features suggest that the spherical magnetite most likely formed in an impact-induced, oxygen-bearing silicate vapor/melt environment. Together with recent discoveries of high-valence iron oxides in Chang'e-5 and Chang'e-6 lunar soils, this study further demonstrates that impact-induced oxidation is a key mechanism for the formation of Fe³⁺-bearing minerals on the lunar surface, providing new constraints on local oxidizing environments and the origin of magnetic anomalies on the Moon. In addition, the Fe³⁺/ΣFe ratio within the outermost ~40 nm of the magnetite decreases to ~56.3%, which is highly consistent with the reduction depth caused by solar-wind H⁺/He⁺ implantation. This provides direct in situ mineralogical evidence for solar-wind-induced reduction of magnetite and has important implications for evaluating the effects of space weathering on the spectral characteristics of magnetite and for future lunar remote-sensing exploration.

Abstract:

Trivalent iron (Fe³⁺) has been confirmed to exist on the highly reduced lunar surface, yet its formation mechanism remains unclear. In this study, using the electron microprobe flank method, we detected Fe³⁺ (Fe³⁺/ΣFe=0～0.31) within 15 impact glass spherules from the Chang'e-5 (CE-5) returned samples. We propose that during meteorite impacts, disproportionation of Fe²⁺ occurs within the melt, generating Fe³⁺; this same disproportionation reaction simultaneously produces metallic iron (Fe⁰), representing a significant pathway for the formation of metal iron particles within impact glass beads. The Fe³⁺/ΣFe ratio in CE-5 impact glass beads containing metallic iron particles show certain negative correlation with Na₂O, K₂O, and P₂O₅, and a positive correlation with CaO and MgO, supporting the impact process simultaneously causing the volatilization of volatile elements and the disproportionation reaction of iron. The origin of Fe³⁺ in homogeneous impact glass beads is the impact process. We observe no correlation between Fe³⁺/ΣFe and Cl as well as SO₃ in the CE-5 glass beads, suggesting that the impact process is highly complex: while disproportionation occurs, the melt simultaneously undergoes high-temperature degassing and subsequent re-incorporation of volatile elements from the impact vapor phase, which compensates partly their loss due to the impact process. This study suggests that the evaporation and reabsorption of volatile elements and the disproportionation reaction of iron occur simultaneously during the impact process, with no obvious causal relationship. Some glass beads containing metallic iron particles exhibit extremely low Fe³⁺ /ΣFe ratios, and the origin of metallic iron particles within the glass beads is complex and not solely attributable to disproportionation reactions.

Abstract:

To constrain the microscale redistribution behavior of volatile components, with S as the main focus, under transient thermal events on the lunar surface, this study employed atom probe tomography (APT) to perform three-dimensional nano- to atomic-scale characterization of a microregion on the surface of a Chang'e-6 lunar soil glass bead. The results show that this microregion is dominated by heterogeneous silicate glass enriched in O, Si, and Al. A columnar microstructural discontinuity was identified within the glass matrix. Across this structure, the concentrations of major elements remain broadly continuous, whereas the trace element S shows local depleted in its core. Meanwhile, density isosurfaces extracted from multiple major elements in this region all show similar columnar structures, which are attributed to local electric-field distortion induced by the physical interface and to trajectory overlap effects during APT analysis. Taken together, these chemical distribution characteristics and physical imaging effects indicate that this structure is not a phase boundary formed by chemical differentiation, but is more likely a microscale physical defect related to local thermal-event modification. The local depletion of S may reflect the redistribution of volatile components, with S being the main focus of this study. These results provide atomic-scale observational constraints on the local distribution of trace volatile components in lunar soil and their relationship with microstructures.

Abstract:

GRV 022905 is a winonaite recovered from the Grove Mountains in Antarctica. In this study, we employed optical microscopy, scanning electron microscopy with backscattered electron (BSE) image, and electron probe microanalysis (EPMA) to investigate its petrological and mineral chemical features. The meteorite displays typical thermal metamorphic recrystallization features, including abundant triple junctions, while no chondrules or relict chondrules are observed. Mineral chemical analyses reveal that the primary mineral assemblage consists of forsterite (Fa_4.8±0.2), enstatite (Fs_4.5±0.2Wo_2.9±0.1), chromian diopside (Fs_2.3±0.2Wo_41.5±0.5), plagioclase (An_25.5±1.5Ab_70.0±1.2Or_4.5±0.2), kamacite, and minor troilite, with accessory minerals such as schreibersite and apatite. Petrographic and compositional data indicate that the sample experienced FeNi metal-troilite partial melting accompanied by melt migration, resulting in depletion of troilite and low Ni content in kamacite. Textural evidence, such as K-rich feldspar (An_2.3Ab_78.4Or_19.3) filling interstices between other mineral grains and plagioclase enclosing subhedral to euhedral orthopyroxene grains (about 10 μm in size), suggests the occurrence of silicate partial melting. GRV 022905 probably represents a product modified by multiple superimposed thermal events, and its petrogenesis can be interpreted by a three-stage thermal evolution model.

Abstract:

Martian soil simulants serve as substitute materials for authentic martian soil and have been widely employed in scientific research and engineering tests. The Martian Garden commercially supplies two martian soil simulants to global researchers: MMS-1 and the enhanced MMS-2. Although both have been utilized in numerous studies, critical essential data on their chemical and mineralogical compositions as well as spectral properties remain lacking, which limits the evaluation of material applicability and in-depth analysis of the related experimental results. In this study, we systematically characterized the chemical and mineralogical compositions as well as spectral properties of MMS-1 and MMS-2 using X-ray fluorescence spectroscopy (XRF), X-ray diffraction (XRD), electron probe microanalysis (EPMA), Fourier transform infrared spectroscopy (FTIR), visible-near infrared spectroscopy (VNIR), and scanning electron microscopy (SEM), followed by an evaluation of their applicability based on these results. The results indicate that the major chemical components of MMS-1 and MMS-2 (such as SiO₂, Al₂O₃, Fe₂O₃, MgO, and CaO) exhibit certain deviations from both the reference data provided by The Martian Garden and the chemical compositions of martian soils in situ measured at various landing sites. Nevertheless, they show a relatively high degree of similarity to the chemical compositions of soils or rocks at certain specific sampling points along the rover traverse paths. MMS-1 primarily consists of andesine, accompanied by minor pyroxene, Al-rich smectite, Mg-rich smectite, Fe(Ⅲ)-rich smectite, quartz, calcite, and hematite, along with trace amounts of gypsum, alunite, olivine, and amorphous silica, and possibly minor illite and indialite. Its VNIR spectrum closely matches observations from Mars orbiters on the global scale. MMS-2, built upon MMS-1, incorporates additional hematite, quartz, gypsum, and periclase, and possibly glauconite, with spectral features more consistent with the orbital data from localized gypsum-enriched areas on Mars. Overall, both MMS-1 and MMS-2 can be regarded as high-quality martian soil simulants. MMS-1 exhibits chemical composition, mineralogical assemblage, and spectral features that are highly similar to those of authentic martian soil, making it a suitable experimental material for scientific investigations related to Mars, including martian geological evolution. In contrast, MMS-2, as a simulant enriched in secondary minerals, confers distinct advantage for investigating the role of secondary minerals in martian soil amelioration. Following detailed characterization of their physical and mechanical properties, MMS-1 and MMS-2 are also applicable to rover engineering tests and in-situ resource utilization (ISRU) studies.

Abstract:

The origin of the Moon is a key issue for understanding the early evolution of the Earth-Moon system and the inner Solar System. Since the Apollo era, the giant impact hypothesis has remained one of the leading hypotheses for the origin of the Moon, but the broad isotopic similarities between Earth and Moon have also imposed important challenges on this model. In recent years, advances in high-precision isotopic analysis, progress in lunar sample chronology, and the return of samples by Chang'e-5 and Chang'e-6 missions have substantially improved our understanding of lunar formation, magma-ocean evolution, and late-stage volcanisms. This paper reviews recent progress in geochemistry, petrology, and isotopic geochronology, with emphasis on the giant-impact origin of the Moon, and the subsequent evolution of the lunar magma ocean. Current studies broadly support lunar formation within several tens to more than one hundred million years after Solar System formation, although significant disagreement remains among different isotopic systems and their interpretations. Samples returned by Chang'e-5 and Chang'e-6 extend known lunar volcanism to about 2.0 Ga and 2.8 Ga, respectively, and provide key constraints for improving the lunar crater chronology and understanding the thermal asymmetry between the nearside and farside.

Abstract:

Baddeleyite (ZrO₂) is an important Zr-bearing mineral in lunar mafic-ultramafic rocks. Owing to its high uranium content, low initial lead, and high U-Pb closure temperature, this mineral serves as a unique chronometer for constraining the timing of lunar magmatic and impact events. This paper reviews recent advances in the study of lunar baddeleyite, focusing on its major formation mechanisms (magmatic crystallization, zircon decomposition, and tranquillityite decomposition) and corresponding morphological features. This paper further discusses how phase transformations recorded in baddeleyite can be used to infer high-temperature and high-pressure events, and summarizes its key contributions to constraining the formation of the lunar crust, mare volcanism, and large-scale impact events. Finally, this review highlights existing challenges in thermodynamic constraints, micro-scale element migration, and U-Pb system complexity in the study of lunar baddeleyite, and outlines future research directions combining high-resolution microanalytical and experimental approaches.

Abstract:

Impact cratering is a critical exogenic process driving the Moon's geological evolution, and the high-pressure mineral phases formed during this process serve as natural thermobarometers and chronometers to record these extreme physical events. The formation processes of high-pressure mineral phases in shocked materials are closely related to the pressure-temperature-time paths of impact events. Therefore, high-pressure mineral phases and their formation mechanisms are extensively utilized for estimating shock conditions and constraining the impact history of the inner Solar System. Meanwhile, as the analogy samples for interior materials in terrestrial planets, high-pressure minerals aid the understanding of mantle transition zones and lower mantle compositions. Therefore, the research of high-pressure mineral phases has great geological significances. This paper reviews the research progress of high-pressure mineral phases formed on the Moon. It elaborates on the physical mechanisms underlying shock-induced mineral phase transitions and the preservation mechanisms of high-pressure mineral phases. In addition, this paper systematically summarizes the mineralogical characteristics, occurrences, and formation mechanisms and conditions of the 15 high-pressure mineral phases currently identified in lunar samples, including stishovite, seifertite, ringwoodite, and majorite. Finally, this paper outlines future prospects of analysing samples returned by future deep space explorations in conjunction with dynamic high-pressure and high-temperature experimental simulations, which will provide critical evidence for reconstructing the lunar impact history and the evolution of the Earth-Moon system.

Abstract:

New minerals from the lunar preserve direct mineralogical evidence for the formation, transformation and preservation of lunar materials under the Moon's extreme physicochemical conditions, including low oxygen fugacity, dryness, high vacuum, intense irradiation and repeated impact processing, serving as a crucial link between lunar sample studies and planetary evolution. Based on returned samples from the Apollo, Luna, Chang'e missions and lunar meteorites, this paper summarizes and discusses the mineral classification, genetic mechanisms and mineralogical significance of new minerals from the lunar. The results show that a total of 10 new minerals from the lunar have been discovered and approved by the International Mineralogical Association Commission on New Minerals, Nomenclature and Classification (IMA-CNMNC) to date. Among them, the new minerals from returned lunar samples all come from the Apollo and Chang'e missions, including pyroxferroite, armalcolite, tranquillityite, yoshiokaite, changesite-(Y), magnesiochangesite-(Y) and changesite-(Ce). The new minerals from lunar meteorites samples include hapkeite, donwilhelmsite and magnesiochangesite-(Ce). These new minerals from the lunar can be classified into the oxygen-containing salt mineral class (mainly silicates and phosphates), the oxide and hydroxide mineral class (mainly oxides), and the class of native elements, intermetallic compounds, and carbides, silicides, nitrides, and phosphides (mainly silicides). Their genesis primarily involves dry and highly reduced magmatic differentiation, impact melting-devitrification and high-pressure phase transformation and vapor-phase deposition space weathering. In recent years, the discovery of the changesite-series rare-earth phosphates, provids new mineralogical constraints on lunar magmatic evolution, behavior of rare earth elements differentiation, and the diversity of lunar materials. Investigations of lunar-related mineral phases that have been previously reported but are not approved as new mineral species are also of great significance for understanding impact metamorphism, volatile preservation, redox processes, and lunar regolith evolution.

Abstract:

This paper discusses the petrogenesis of the two-mica granite and its genetic relationship with pegmatite in Jiajika area, west Sichuan Province, by detailed field investigation and laboratory analysis. The whole rock analytical results show that SiO₂ content of two-mica granite is 73.93%~75.06%, and total alkali is 7.90%~8.36% with high concentration of K, suggesting high-K calc-alkaline series; the content of Al₂O₃ is 14.24%~14.77%, and A/CNK=1.14~1.24, implying strong peraluminous S type granite; ΣREE=31.18×10^-6~41.67×10^-6,LREE/HREE=4.15~6.41,δEu=0.46~0.70, and CaO/Na₂O=0.07~0.12(<0.3),indicating that its source might have been pelite with rare content of psammite, and high ratio of Al₂O₃/TiO₂ (133.1~279.8) implies that it is high-pressure-low-temperature post-collision granite. The SiO₂ content of the granite pegmatite is 72.59%~80.91%, the total alkali is 5.26%~10.60%, Al₂O₃ is 11.79%~17.64%, σ=0.74~3.80; A/CNK=0.98~2.38; ΣREE=4.03×10^-6~8.29×10^-6, LREE/HREE=2.61~10.40, and δEu=0.18~0.68. There are considerable differences between two-mica granite and granite pegmatite in the aspect of the content of major and trace elements. And there is close genetic relationship between granite and pegmatite in the area. Magma immiscibility might be the key factor for the formation of (ore-bearing) granite pegmatite. The pegmatite melt riched in volatile components might be separated during the upwelling of granite magma and metasomatized minerals in wall rock to further concentrate rare metal elements during its migration. The difference between two-mica granite and pegmatite might cause the apparent differences in REEs and elements such as Th, Sr, Ti, Y, Rb and Nb. The different characteristics of pathways and environments that the pegmatite melt passed and emplaced might have resulted in element concentration variance in different sites. In comparison with two-mica granite, there existed a certain degree of jumping characteristic during the formation and evolution of the pegmatite in Jiajika area.

Abstract:

Guilin Chicken Blood Red Jasper (CBRJ) is a kind of quartz jasper. It is characterized by bright red to black colors and high hardness. However, few researches have been focused on the field occurrence, geological background, rock structure and genesis of its color. Field surveys indicate that the Guilin CBRJ is hosted in low-grade metamorphic sandstones which experienced vapor-water hydrothermal metamorphism and iron oxide dissemination. It occurs in the Sanmenjie Formation of Neoproterozoic Danzhou Group in Longsheng area in the north of Guangxi. Tectonically, the ore deposit of Guilin CBRJ is located at the juncture of Yangtze and Cathaysian plates, which has undergone a complex geological process. Its formation was related to multi-phase tectono-magmatic activities from Neoproterozoic to Triassic. Detailed analyses of mineralogy, micro-texture and geochemical composition of Guilin CBRJ were carried out by polarizing microscope, X-ray diffraction, and electronic microprobe. The results indicate that the CBRJ is mainly composed of quartz and hematite, with dolomites in some samples. Quartz grains exhibit two types of allotriomorphic equigranular texture and idiomorphic porphyroblastic texture. The latter one, in which distinct enlargement texture can be observed, reveals a metasomatic metamorphism phase. Hematite occurs in three types: ① single crystal existent between or inside the quartz particles, ② dusty crystals wrapped in the quartz particles, and ③ disseminated crystals filled between the quartz particles. The Fe³⁺ in the hematite should be responsible for the color of the CBRJ. Electron microprobe analysis shows that the hematites of single crystal and disseminated crystals have 78.9%～85.6% iron oxides, but the dusty crystal is too small to be analyzed. In combination with the different generations of quartz and hematite, the authors have reached the conclusion that the formation of different types of these minerals in the Guilin CBRJ was consistent with the regionally geological evolution in this area.

Abstract:

The Hongyuntan iron deposit is hosted in pyroclastic rocks of the Lower Carboniferous Yamansu Formation. The ore bodies occur as layers, stratoid bodies or lenses. The principal ore mineral is magnetite, together with minor maghemite, specularite, pyrite and trace chalcopyrite. The gangue minerals include garnet, diopside, actinolite, chlorite, tremolite, epidote, biotite, albite and quartz. The ore structures are mainly of massive and disseminated forms, with occasional banded or veined forms. The ore textures are of subhedral-anhedral granular and metasomatic types. The wall rock alteration shows symmetrical zoning, and the alteration colors change from dark to light from ore bodies outwards. On the basis of observed mineral assemblages and ore fabrics, two periods of ore deposition were recognized, i.e., skarn period and hydrothermal ore-forming period, which could be further subdivided into four metallogenic stages, namely skarn stage, retrograde alteration stage (main ore-forming stage), early hydrothermal stage and quartz-sulfide stage. Electron microprobe analyses show that the end member of garnet is mainly andradite-grossularite. The composition of pyroxene is mainly diopside-asteroite. The amphiboles is composed mainly of actinolite and tremolite with minor magnesiohornblende. The composition of these skarn minerals suggests that skarn in the Hongyuntan iron deposit is calcic skarn, belonging to metasomatic skarn. The characteristics of main and trace elements suggest that the formation of magnetite was closely related to the skarn. In combination with geological characteristics, the authors suggest that the skarn might have resulted from interaction between Ca-rich pyroclastic and Fe-rich magmatic hydrothermal fluid which was transported along the fault system. The formation of magnetite was hence related to the regressive metamorphism of the skarn.

Abstract:

This paper has mainly recommended a mineral abbreviation list (see Table 2 and Table 3). Table 2, which contains 243 minerals, was compiled by IUGS Subcommittee on the Systematic of Metamorphic Rocks (SCMR) in 2007. The author selected other 29 minerals and, on such a basis, formulated Table 3. Thus, the total mineral abbreviations come to 272. It is hoped that they can be popularized in future and become more and more perfect through utilization, so as to provide a basis for ultimate standardization and unification.

Abstract:

This paper presents partition coefficients of 69 chemical elements (Li, Rb,Cs, K, Na, Ca, Ba, Sr, Mn, Fe, Mg, Cu, Pb, Zn, Co, Ni, Be, La, Ce, Nd,Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Y, Sc, Cr, In, Ga, Al, B,Cd, Sb, Bi, U, Th, Zr, Hf, Si, Ti, Ge, Sn, Mo, Nb, Ta, W, V, P, F, Cl,S, N, O, C, As, Pu, Re, Os, He, Ne, Ar, Kr and Xe) and the univalent radical (OH) in 28 minerals (olivine, clinopyroxene, orthopyroxene, amphibole,biotite, Phlogopite, plagiocla-se, K--feldspar, quartz, magnetite, ilmenite, garnet,zircon, apatite, allanite, topaz, sphene, cordierite, hauyne, leucite, nepheline,whit-lockite, brookite, petovskite, melilite, armalcolite, spinel and rutile) from 8 types of rocks, namely metaluminous (ultra) basic rock, peralkaline (ultra) basic rock, metaluminous intermediate rock, peralkaline intermediate rock,metaluminous acid rock, peralkaline acid rock, peraluminous acid rock and ultra-acid rock. It is found through an integrated ahalysis and comparison that the composition and structure of minnerals and melts seem to be the most important factors controlling mineral-melt element partitioning. Importanceshould be attached to minral structure and Al-supersaturation of melt which have, not been discussed by research workers. Finally, the present state and theproblems to be solved in the study of mineral--melt element partition coefficients are analysed, and the future trends of this research field are predibted.

Abstract:

本文以表格的形式列举了经国际矿物学协会(IMA)新矿物与矿物命名委员会(CNMMN)批准、并于2003年度正式发表的新矿物共55种,其中硅酸盐31种,磷酸盐5种,砷酸盐2种,硫酸盐4种,硫化物3种,碳酸盐2种,钒酸盐2种,硼酸盐1种,硒化物1种,硫盐1种,氧化物1种,氢氧化物1种,复杂卤化物1种.文中表格依次列出了矿物的中外文名称及化学式、晶系及晶胞参数、主要粉晶数据、物理性质、光学性质、产状及共生(伴生)组合等.

Abstract:

The combination of multi-collector inductively coupled plasma mass spectrometry (MC-ICPMS) and laser ablation provides a useful tool for tracing the geological process by analyzing minerals under microscales. As one of the non-traditional stable isotopes, boron isotope has attracted more and more attention. In this study, the authors developed an in-situ method for high-precision analysis of B isotope in tourmaline with high-content boron and muscovite with low-content boron. Tourmaline and glass reference materials were applied to correcting the mass fractionation respectively, and in-situ B isotopes of two natural samples from southwestern Tianshan were also tested. In addition, the boron isotope of the in-house standard T-PKU was calibrated as -13.07‰±0.42‰ (2SD, n=66). The above testing results reveal that the condition of LA-MC-ICPMS is stable for a long term and suitable to producing high quality data about tourmaline with minimum spot size of 10 μm and muscovite with > 20×10^-6 B concentration. The B isotopes of tourmaline and paragonite in Tianshan samples are helpful for tracing fluids sources.

Abstract:

The geochemical characteristics and abnormal sources of As, Cd, Cr, Cu, Hg, Ni, Pb and Zn in the soil of Southern Xuancheng were analyzed and studied by using the 1:250 000 land quality geochemical survey data. It is found that the geological background is the main controlling factor for the content of soil elements, and that the spatial distribution characteristics of heavy metal elements in the surface and deep soil in the area are significantly consistent with the geological background and sedimentary environment. The high content of heavy metal in the soil parent rock geological background (Hetang Formation, Piyuancun Formation and Lantian Formation, etc) is the main influencing factor for the high anomaly of soil heavy metal elements. In addition, mining and atmospheric dry and wet deposition are also one of the factors affecting high anomaly of heavy metals in soil. It is found that Pb, Hg, Cd and Cr in soil have input sources of atmospheric dry and wet deposition. The main impact index of heavy metal in soil pollution risk in the survey areas was Cd. The proportion of samples that soil Cd exceeded the control value of soil pollution risk of agricultural land was 2.56%. The morphological analysis results show that soil Cd is mainly in ion-exchange state. Combined with crops investigation, it is found that there is a certain ecological risk in the area with high abnormal soil Cd.

Abstract:

Quantitatively determining the timescale during mantle-derived magma ascent from the source to eruption or emplacement is essential for the understanding of magmatism, however, the timescales of eruption/emplacement are still poorly constrained. Shanxi Datong Cenozoic volcanic field, north of the North China Craton, is an ideal area for the investigation. In this study, we focused on the mantle olivine xenocrysts entrained in ca. 0.2 Ma Shenquansi alkali basalt, and its timescale of residence in the host magma prior to eruption. According to mineral chemistry, cores of these mantle olivine xenocrysts have Fo values up to 97.7, which can be defined as extremely magnesian olivine. They are also characterized by the extremely low contents in Ca, Mn and Ni, suggesting they were captured from metasomatized mantle peridotite. Moreover, both of the mantle olivine xenocrysts display complex CaO profiles, attributed to complex magmatic processes in the magma plumbing system. The reaction rim widths of one olivine xenocryst vary significantly, implying it has experienced multiple crack processes when captured or dur- ing transport. The Fo values of the mantle olivine xenocrysts rims are about 70, indicating they are in diffusion equilibrium with the host magma (alkali basalt) at rims. Timescales obtained by Fe-Mg diffusion chronometry of olivine mantle xenocrysts show that they have only resided in the magma for months. For a lithospheric mantle thickness of 40~70 km, the fastest average ascent rate may exceed 500 m/d.

Abstract:

Early Paleozoic volcanic rocks in Tianshui and Baoji areas along the eastern segment of North Qilian orogenic belt consists of Hongtubu basaltic lavas and Chenjiahe intermediate-acid volcanic rocks. Geochemical analyses show that Hongtubu basaltic lavas are similar to the intercalated basalts in Chenjiahe intermediate-acid volcanic rocks in characteristics, both fallen in the tholeiite series with high TiO2 (1.50%～2.73%). Their∑REE are 65.97×10-6～133.46×10-6 and 78.04×10-6～175.55×10-6 respectively， both are slightly enriched in LREE ［(La/YbN being 2.00～4.40 and 2.71～4.40 respectively］，and both have no obvious Eu anomaly or weak Eu negative anomaly（δEu being 0.85～1.10 and 0.85～0.99 respectively）. Basalts from two groups are typically characterized by selected enrichment of LILEs, low abundances of HFSEs relative to NMORB, and prominent troughs of Nb and Ta, with low Nb/La ratio（0.28～0.43）, which indicates the affinity of these volcanic rocks to island arc tholeiite（IAT）. In addition, εNd（t）（+2.22～+4.08）values of basalts suggest that their mantle sources are similar to the depleted mantle source. Zr/Nb=17.21～36.33 and Ce/Nb=5.73～8.17, implying geochemical characteristics of N-MORB. Sr, Nd and Pb isotopes from Hongtubu basalts are similar to those in Chenjiahe basalts in composition. In the diagrams of εNd(t)-(87Sr/86Sr)t, (207Pb/204Pb)t-(206Pb/204Pb)t,(87Sr/86Sr)t-(206Pb/204Pb)t and εNd(t)-(206Pb/204Pb)t for basalts, the data are fallen in the DM, EMⅠand EMⅡ areas, probably with a little crustalontamination, indicating that the magma of basalts might have had a mixed gin.Thentermediate-acid volcanic rocks from Chenjiahe belong to the calc-alkaline series,they have relatively high abundances of REE∑REE=127.51×10-6～276.01×10-6）, and are significantly enriched in LREE[（La/YbN= 4.79～13.51]. Most intermediate-acid volcanic rocks show weak Eu negative anomaly (δEu=0.53～1.20). The trace element patterns of Chenjiahe acid volcanic rocks are similar to those of the ocean ridge granite (ORG), with marked troughs of Nb, Ta, Zr and Hf. A synthetic study shows that the Chenjiahe intermediate-acid volcanic rocks in the eastern segment of North Qilian orogenic belt were formed in an island-arc setting, whereas the Hongtubu basalts were formed in an intra-arc rift setting (or an initial back-arc basin setting), probably being products of the early spreading evolution of the island_arc system towards the back-arc basin in the eastern segment of North Qilian during late Early Paleozoic. The results obtained provide evidence for the existence of the trench-arc-basin system at the juncture of Qilian and North Qinling orogenic belts.

Abstract:

The Cuonadong leucogranite is one of the most important parts of North Himalayan leucogranite belt. Geochemical data show that Cuonadong leucogranite is the calcium alkaline and strong peraluminous granite with high silica (SiO₂ is 74.20%~74.52%), poor iron (Fe₂O₃ is 0.04%~0.20%, FeO 0.04%~0.58%), poor magnesium (MgO is 0.06%~0.14%), and calcium alkaline (σ is 2.15~2.32) as well as strong peraluminous nature (A/CNK is 1.11~1.15). Its total rare earth is relatively low (∑REE is 47.24×10^-6~57.59×10^-6), with enrichment of LREE (LREE is 39.85×10^-6~49.23×10^-6), depletion of HREE (HREE is 6.91×10^-6~8.68×10^-6) and obvious negative Eu anomaly (0.49~0.80). It is characterized by an enrichment of some large ion lithophile elements (Rb, Th, U, K) and loss of high field strength elements (Nb, Ta, Zr Ti). Zircon U-Pb dating results show that the Cuonadong leucogranite's formation time is Miocene (21 Ma), which belongs to the peak of the late stage of north Himalayan leucogranite (24~12 Ma). Zircon εHf(t) values are negative with a wide variation (-3.92~-17.64), which shows that its magma source was the crust, mostly from the metapelite, with the probable mixing of many kinds of materials in its source. The petrogenesis of Cuonadong leucogranite is that the high Himalayan crystalline rock series experienced decompression melting during the rapid pull-back of the plate in the post-collision tectonic setting, with the initial magma crystallization temperature being 675~702℃.

Abstract:

In this paper,LA-ICP-MS zircon U-Pb dating was carried out for four samples of volcanic rocks from Qingshan Group in Jiaodong area and, as a result, their concordant ages were obtained, which are 119.4±0.9 Ma, 118.2±1.0 Ma,120.2±0.9 Ma and 120.0±0.8 Ma, respectively. The results show that all the volcanic rocks in Jiaodong area were formed from about 120 Ma to 118 Ma in the Early Cretaceous period. The ages of Qingshan Group volcanic rocks from Shandong Province controlled by Tan-Lu fault are similar to those from the Su-Wan segment of the Tan-Lu fault zone,but younger than those around the Tan-Lu fault zone,which indicates that the duration of volcanic eruption along Tan-Lu fault is probably longer than the duration in other areas under the background of lithospheric thinning in eastern China. Geochemically, all the intermediate and acidic volcanic rocks have high K₂O, ALK, LREE values and low MgO, TiO₂, Ni, Cr, HREE values. According to the geochemical features, the volcanic rocks can be subdivided into trachyte-trachydacite and rhyolite. The trachyte-trachydacite is characterized by LILE enrichment(Rb,Ba,K)and HFSE depletion(Nb,Ta,Ti,P), but the rhyolite exhibits stronger depletion of Ba,Sr and HFSE (Ti,P). Compared with the rhyolite,the trachyte-trachydacite possesses higher Sr and Ba values as well as La/Nb and Ba/Nb ratios,but lower Rb/Ba ratios and δEu values. All these data indicate that they might have been derived from different magma sources. It is inferred that the trachyte-trachydacite rocks were derived from the mixture of the partial melting of the lower crust(Yangtze Craton or North China Craton)and enriched lithospheric mantle. In addition, the rhyolites were related to the partial melting of the lower crust in the regional extension environment and high geothermal anomaly background with crystallization differentiation during the magma evolution.

Abstract:

Highgrade black jadeite is a kind of upscale and fashionable jade material that has become one of the jadeites characterized by fastest growing values in the past 20 years. Based on a comparison of mineralogical and geochemical characteristics between black jadeites (inky black jades）from different producing areas of the world, the authors hold that the black jadeites currently on the market can be mainly classified into jadeite jade, omphacitic jadeite jade and hornblende jade whose main components are jadeite, omphacite and dark green hornblende respectively. They include blackchicken jade, ink jadeite and blackkosmochlor from Myanmar and jade negro and galactic gold from Guatemala, with blackchicken jades similar to those from Myanmar also seen in Japan and Kazakhstan. The research results suggest that the main mineral composition, jade structure and inclusion characteristic combinations of black jadeite jades from different producing areas have their respective typomorphic natures, which can be used as the distinctive characteristics for their sources.

Abstract:

Cordierite is a mineral material characterized by low thermal expansion coefficient and good thermal shock resistance. Cordierite mineral material is relatively rare in nature, so cordierite is synthesized usually by the method of artificial synthesis. Based on the newest investigation results of synthetic cordierite, this paper deals with the progress of researches on such synthesis methods of cordierite as high purity oxide solid reaction at high temperature, natural mineral solid reaction at high temperature, the utilization of industrial wasted materials, the employment of agricultural wasted materials, the sol-gel and the low-temperature combustion synthesis. At present, the method of natural mineral solid reaction at high temperature is used for the preparation of cordierite in industry. In spite of a lot of advantages, this method also has many disadvantages. Therefore, the development trend of cordierite synthesis seems to solve the problem as to how to apply other synthesis methods to industrial preparation.

Abstract:

Petrology, geochemical and Nd isotopic data are reported for the Neoproterozoic Danba metabasalt in the Kangdian Rift on the western margin of the Yangtze block. Samples were collected from alkaline basalts, which are enriched in MgO, TiO₂, with Mg^# being 0.51～0.59. They have high total rare earth elements and show high fractionation between LREE and HREE. The trace elements are characterized obviously by enrichment of Th, Nb, Ta, Zr, Hf and LREE but depletion of Y and HREE. Their geochemical and Nd isotopic characteristics suggest that they are similar to OIB. The basaltic magma was generated in an intraplate setting, and was generated by partial melting of OIB mantle source region, with variable degrees of contamination of SCLM during magma ascending; in addition, some samples might have experienced contamination of the lower crust. These samples reveal some plume magmatism characteristics in petrochemistry, and imply that magmatism was probably related to the Neoproterozoic plume event, which resulted in the breakup of Rodinia supercontinent.

Abstract:

The newly-exposed lower strata of the Xiamaling Formation near Tielingzi Village in Jixian County contain rich siderites. This paper reports the basic geological characteristics of these siderite-rich strata in terms of the field outcrop, petrology and major elements. Studies show that the profile is characterized by black shale interbedded with silty iron-rich layers/siderite concrete layers, and also has minor siltstone. Some iron-rich strata have turned into limonite layers in the outcrop because of intense weathering. Siderite is the main iron mineral phase in the strata. Siderites can form iron concretes, showing micritic or microcrystalline granulitic textures under the microscope, or form silty ferruginous layers with almost a comparable amount of silty quartz; it can also distributed sporadically in siltstone and black shale with relatively coarse particles. There also exists very little siderite residue in weathered limonite layers. The overall features of major elements show that the strata are rich in SiO₂, TFe and TOC, but poor in MnO, CaO, MgO, P₂O₅ and S. Except for ferriciron in weathered layers, there is mainly ferrous iron in the strata. The TOC content decreases in order of siderite concrete, silty iron-rich layer, black shale and siltstone. The correlation diagram between TFe and Al₂O₃ content shows a negative correlation in iron-rich layers, while a positive correlation between them exists in normal black shale and siltstone, which suggests that iron in the former form originated from the ocean itself, while iron in the latter form originated mainly from terrigenous detritus. In addition, FeO content has a positive correlation with TOC content in fresh samples, which implies that the genesis of siderites may have some relationship with organic matter.

Abstract:

At present, the infrared transmission spectroscopy is the best technique for determining whether jadeite is polymer-impregnated or not, and the infrared reflectance spectroscopy is a nondestructive and rapid determination method that provides mainly the fundamental frequency vibration spectra data of minerals and shows new application potentials in gemological research, especially in the identification of gem species. The gemological application of IR reflectance spectroscopy and the identification system of IR spectra of gems, including a database of 318 spectra and a searching and identifying program, are described in this paper.

Abstract:

As more and more treated turquoises appear on Chinese gem market, the authors collected lots of turquoises from different deposits on Chinese gem market in order to sum up the characteristics of the natural turquoises on Chinese gem market. At the same time, different types of treated turquoises were studied to find general difference between them and natural turquoises. The results show that natural turquoise and treated turquoise have different shades of color, inclusions and appearances. IR spectra of both natural and treated turquoises were studied, indicating that there are absorption peaks at 1 735, 1 600 and 1?500 cm^-1 in treated turquoises, which are caused by the man-made polymer. If the turquoise is treated by polymer, there are absorption peaks at 1 735, 1 600 and1 500 cm^-1 in a turquoise, and this can serve as convincing evidence in this aspect.

Abstract:

From the discovery of the first new mineral hsianghualite in 1958 to the end of 1995,74 new minerals found in China had been approved by IMA CNMMN. Among them, 2/3 were discovered after 1981. The discovery of new minerals in China has the following features:(1) With the development of analytical methods, the number of new minerals discovered per year increases gradually: from the end of 1950s to 1960s, only one new mineral was discovered every year on the average, whereas from 1980s till now, three new minerals were discovered averagely every year. (2) The structures of many new minerals have been determined. (3) Most of the new minerals are in the lower category, mainly in the monoclinic system, and perfect crystals are rare; hsianghualite has the most abundant crystal faces, whose ideal faces can reach 146. (4) Among those new minerals, silicates take the first place in number, followed by native elements, alloys, and then oxides. (5) The modes of occurrence of new minerals are varied, most of them occurring in oxidized zones of various deposits and deposits related to ma fic or ultramafic rock masses. There are a few new minerals occurring in skarn and placer deposits or even in cosmic dusts and meteorite.(6) The new minerals are characterized by wide but uneven distribution. Till now, new minerals have been discovered in 20 provinces or autonomous regions, especially in Hebei, Qinghai, Inner Mongolia and Henan. The number of new minerals found in North China is larger than that found in South Chine. (7) The number of discoverers of new minerals is in tens. The first discoverer of new mineral is Prof. Huang Yunhui, whereas Prof. Yu Zuxiang is the one who discovered the most numerous new minerals in China, totally disclosing 11 new minerals by himself or together with other experts. Most of the discoverers are members of the Chinese Academy of Geological Sciences, China University of Geosciences, and Institute of Geochemistry, Academia Sinica as well as other educational and scientific research institutions. The discovery of new minerals has promoted the development of mineralogy in China. Tens of discoverers were awardees of the National Natural Sciences Prize or the Science and Technology Progress Prize of the Ministry of Geology and Mineral Resources for the discovery and research results of new minerals in 1980s. More than 60 new mineals discovered in China were collected by the Geological Museum of China, with some of them exhibited in the Minerals and Rocks Exhibiting Room.

Abstract:

Indosinian S-type granites are widely distributed in central Inner Mongolia on the northern margin of North China landmass. Spread in nearly EW direction, the granites have formed a gigantic compound granite belt, with porphyritic biotite-admellite and moyite being the two main types. SiO2is abundant, Al2O3is 12.38%~15.34%. A/NKC (molecule ratio)>1.1, K2O/Na2O=1.1~3.1,δ=1.9~2.6,ΣREE is 45.778 ×10-6~486.501×10-6, andδEu=0.1~0.8. A series of zircon U-Pb surface ages (207~227 Ma) for the granites have been recently obtained from 1/50 000 regional geological survey. As the lithofacies and geochemical characteristics of the granites are similar to those of S-type granites, the authors conclude that the Indosinian granite in this area was formed in a post-collision setting instead of in the setting of syn-collision between North China plate and Siberia plate.