Abstract:

Late Jurassic granite in Jiaodong area is mainly exposed in Zhaoyuan, Laizhou, Wendeng, Rushan and other areas, including Linglong pluton and Queshan-Kunyushan pluton. In between, the Qixia region is dominated by Archean TTG-type rocks. This time, many meso-grained monzogranite xenoliths were found in the diorite porphyrite veins (surrounding rock is TTG type rock) in Shangqujia village, Qixia area, the SHRIMP U-Pb age of zircon from monzonitic granite is 161.0±2.2 Ma. The ratio of ¹⁷⁶Hf/¹⁷⁷Hf ranged from 0.281 929 to 0.281 971, the εHf (t) was -26.39 to -24.77, t_DM2 was 2 871 to 2 773 Ma. The monzogranite xenoliths are characterized by high potassium, high aluminum,low magnesium and iron. They are peraluminous, high potassium calc-alkaline rocks, which are deficient in heavy rare earth elements and have obvious fractionation of light and heavy rare earth elements. The ratio of (La/Yb)_N varies from 28.11 to 78.50, there are obvious Eu positive anomalies (Eu/Eu^*=1.16~1.77), and the large ion lithophilic elements Rb, K, Ba and Sr are relatively enriched. Its isotopic geochronology, petrology, and rock geochemical characteristics are basically consistent with those of the Linglong pluton and the Queshan-Kunyushan pluton. It is the result of partial melting of the crust thickened by the collision between the Yangtze plate and the North China plate under the background of the movement of the ancient Pacific plate. The source area is mainly composed of TTG type rocks. This article believes that these diorite xenoliths belong to the Linglong period granite. Based on the interpretation of regional gravity anomalies, it is believed that there is a hidden Linglong period granite body in the lower part of TTG rocks in the Qixia area. It is speculated that the range extends from the Douya fault in the west to the Taocun fault in the east, to the northern edge of the Jiaolai Basin in the south, and to the southern edge of the Zangjiazhuang Basin in the north. The Linglong pluton and the Queshan-Kunyushan pluton may be connected in the deep part.

Abstract:

The Houhe Complex is an important part of the early Precambrian basement rocks in northern margin of the Yangtze Block. However, its genesis and tectonic setting are still unclear, which restricted our understanding on the geological evolution of northern margin of the Yangtze Block and even the entire Yangtze Block during the Paleoproterozoic period. In this study, analyses of whole-rock major and trace elements, Sm-Nd isotopes, zircon U-Pb geochronology and in-situ Lu-Hf isotopes are performed on trondhjemite and monzogranite from the Houhe Complex in Beiba area, northern margin of the Yangtze Block. The U-Pb dating results show that the crystallization ages of trondhjemite and monzogranite are 2 101±10 Ma and 2 072±15 Ma, respectively. The trondhjemite samples exhibit the characteristics of high silicon and sodium, low potassium and magnesium. Most samples belong to metaluminous to weakly peraluminous and calc-alkaline I-type granitic rock series and exhibit characteristics of island arc granite. Their zircon εHf(t) values range from -0.8 to + 4.6, with whole-rock εNd(t) values ranging from +0.1 to +1.1 and two-stage Hf model ages (t_DM2) ranging from 3 005 Ma to 2 469 Ma. In contrast, the monzogranite rocks show low silicon, but high magnesium, aluminum and potassium, belonging to weakly peraluminous and high-K calc-alkaline I-type granite. Their total rare earth element concentrations are relatively high. The differentiation between light and heavy rare earth elements is obvious, accompanied by weak negative Eu anomalies. The monzogranite rocks are also enriched in large ion lithophile elements (Rb, Ba and Th), and depleted in high field strength elements (Nb, Ta and Ti). They have high Mg^# values, and Cr and Ni contents, with zircon εHf(t) values of - 2.9~+ 2.4, and whole-rock εNd(t) values of +0.1~+0.9 and two-stage Hf model ages (t_DM2) of 2 939~2 604 Ma. All these data indicate that the trondhjemite was mainly produced by partial melting of Neoarchean basaltic rocks in the lower crust, with a certain degree of fractional crystallization. The monzogranite was generated by partial melting of ancient Neoarchean continental crust caused by underplating of mantle-derived magma, with addition of lithospheric mantle material. Considering the temporal and spatial distribution, and petrogenesis of the late Paleoproterozoic (2.1~2.0 Ga) mafic-felsic magmatic rocks reported in northern margin of the Yangtze block, it is supposed that the Paleoproterozoic (2 101~2 072 Ma) granitoid rocks from the Houhe Complex in Beiba area, northern margin of the Yangtze block, were formed under an active continental margin arc setting, related to convergent process of global Paleoproterozoic Columbia supercontinent.

Abstract:

The hydrothermal dolomite (HDS) is a significance ore-bearing wall rock of the MVT Pb-Zn deposit. However, the distribution pattern of hydrothermal dolomite along faults remains unclear, making it as a prospecting indicator of MVT deposit is uncertain. The MVT Pb-Zn ore concentration area in Sichuan, Yunnan and Guizhou on the southwestern margin of the Yangtze platform is generally characterized by HDS ore-endowments. This study focuses on the ore-bearing HDS in the Longjie exploration area of northeastern Yunnan. Through geological mapping and petrographic observation, combined with mineral elemental composition and C-O isotope analysis, and a comparison with buried dolomite, the distribution characteristics of ore-bearing HDS along faults were systematically clarified. The results indicate: ① The ore-bearing HDS is produced along the secondary fracture of the upper disk of the strike-slip normal fault or thrust fault, and the distribution range along the upper disk of the fault is larger than that of the lower disk of the fault. HDS is formed by accounting limestone or dolomite on both sides of the fault. The closer the distance from the fault, the shallower the color, and the larger the crystal size of dolomite. ② The contents of V, Cr, Cu, Zr, Rb and Ba in HDS are higher than those in buried dolomite, and the farther away from the fault, the higher the content is. The distribution pattern of rare earth elements is right-inclined, there are δCe negative anomalies (0.61~0.98) and δEu weak positive anomalies (0.74~1.07), both of which decrease symmetrically away fromt the fault. ③ The dolamitization of HDS in the area occurred in a reduced environment and underwent a process from burial to tectonic hydrothermal alteration, with fluid migrating to both sides along the fault. Therefore, the contents of V, Rb, Zn, Pb and δ¹³C value of HDS increase from the fault to the surrounding rock, which can sever as effective exploration indicators for MVT Pb-Zn deposits.

Abstract:

The BIF-type iron deposit at Sijiaying in eastern Hebei Province is considered one of the most representative banded iron deposits in China. A systematic investigation of ore and mineral characteristics holds significant implications for understanding the metallogenic evolution of BIF-type iron deposits. In this study, we conducted comprehensive petrographic observations on various typical iron ores from this mining area, and combined them with in situ electron probe (EPMA) testing and analysis, five distinct magnetite types were identified. Furthermore, we identified four stages of metallogenic evolution: the initial sedimentary stage, metamorphic deformation stage, hydrothermal alteration stage, and epigenetic oxidation stage. EPMA results were obtained for magnetite, biotite, chlorite, and hornblende. By analyzing the chemical characteristics of magnetite and calculating the different formation temperature of biotite and chlorite, and considering changes in the metallogenic environment indicated by their chemical characteristics, it indicated that a typical feature of sedimentary metamorphism is present in the early stage of the deposit and that it suffered from metamorphism, deformation, and hydrothermal effects in the later stage. Combined with geological features, petrographic characteristics of ore minerals and gangue minerals, major element analysis, and other studies, we considered that the oxidation after uplifting to the surface had less influence to the deposit; the enrichment of Fe may be related to the migration of elements such as Mg, Mn, and Ca. The end of the metamorphic deformation stage to the hydrothermal alteration stage is the most important stage for the formation of Fe-rich iron ore in the BIF-type iron deposit at Sijiaying in eastern Hebei Province.

Abstract:

The Waxing Mo polymetallic deposit is a newly discovered porphyry type deposit in the Lesser Xing'an Range-Zhangguangcailing metallogenic belt. There are several periods of magmatic activity in the mine area. Zircon U-Pb dating results show that the emplacement ages of monzonite granite, granodiorite and biotite monzonite are 177±1.9 Ma~174±1.2 Ma, 170±1.9 Ma~169±2.1 Ma, and 172±1.5 Ma~172±1.4 Ma, respectively. The three types of granites are all characterized by high SiO₂ (64.41%~77.77%) contents, and are enriched in large ion lithophile elements, depleted P₂O₅ (0.02%~0.21%) and high field strength elements such as Nb and Ta. The A/CNK values are between 0.99 and 1.21], suggesting they belong to high-K calc-alkaline metaluminous-slight peraluminous type I granite. The whole rock Nb/Ta ratio (7~13) is comparable to that of the crust. Zircon εHf(t) values range from 3.9 to 18.8, indicative of juvenile crustal origin. A number of mafic microgranular enclaves (MMEs) are observed in these granitoids, suggesting that mantle-drived magma was involved in the source region. Combined with the regional tectonic evolution history, we believe that the granite in the Waxing ore field was formed in the late collision-post-collisional setting. We found that granodiorite and biotite monzonitic granite have good spatial relationship with Cu-W and Mo-W mineralization, respectively, and their emplacement ages are correlated with the weighted average age of molybdenite Re-Os (169.0±2.2 Ma; MSWD=0.042). These support the granodiorite and biotite monzonitic granite are syn-mineral intrusion, while the monzonite is pre-mineral pluton. Combined with zircon U-Pb chronology and Hf isotope characteristics, the biotite monzonite granite and granodiorite may be the products of different magmatic evolution degrees at the same time, and higher evolution degrees may be conducive to Mo enrichment in magmas. Ratios of granite (La/Yb)_N decrease abruptly from pre-mineral to syn-mineral intrusions, probably indicating a transition from compression to extension, which may be conducive to Mo formation.

Abstract:

Uraninite is a typical mineral of uranium-bearing granite and the most important source mineral of uranium for the formation of granite-related uranium deposits. Understanding its compositional characteristics and crystallization age is significant for revealing the uranium mineralization process. The Xiazhuang uranium ore field in northern Guangdong is an important granite-related uranium deposit in China. In this study, textures and chemical ages of uraninite from the Xiazhuang granite and the altered granite at the Shituling uranium deposit were investigated using EPMA. The results indicate that uraninite in the Xiazhuang granite (Urn-1) is enclosed in rock-forming minerals, and the uraninite near the ore granite of the Shituling uranium deposit (Urn-2) is intergrown with pyrite and occurs between rock-forming minerals. EPMA data yielded the chemical ages of 233±3 Ma and 156±2 Ma for Urn-1 and Urn-2, respectively. The former is consistent with the zircon U-Pb age of the Xiazhuang granite, indicating that Urn-1 is of magmatic origin. Hydrothermal alteration of the altered granite mainly includes muscovitization and chloritization, corresponding to the early stage of uranium mineralization of the Shituling deposit. These altered samples have higher whole-rock U contents (55.5×10^-6~118×10^-6) and lower Th/U ratios (0.15~0.35) relative to the fresh rocks, indicating that these samples were influenced by uranium-rich fluids, and Urn-2 crystallized from that fluid, suggesting a hydrothermal origin. The chemical age of Urn-2 further indicates that uranium mineralization of the Shituling uranium deposit took place at the Late Jurassic. Some uraninites have been altered, and UO₂ contents of the altered domains are 33.83%~56.01%, obviously lower than the unaltered domains (UO₂=86.21%~95.91%), which may suggest the mobilization and mineralization of uranium related to hydrothermal activity.

Abstract:

The detrital composition is one of the key factors affecting the diagenesis and reservoir physical properties of tight sandstone reservoirs. In order to find out the control mechanism of the deformable compositions on the reservoir, taking the Shanxi Formation in the H well area of the Daniudi gas field as an example, through microscopic observation and statistics of rock thin section, combined with the physical properties, we analyse the controlling effect of deformable compositions on diagenesis, and then discuss their control and mechanism on the reservoir. The results show that the plastic composition of the Shanxi Formation is a tuffaceous matrix, and the semi-plastic compositions include tuff, slate, phyllite, schist, and mudstone detritus. The deformable components mainly control the reservoir through compaction and dissolution, and the compaction pore reduction rate is positively correlated with the content of deformable compositions, in which the effect of tuffaceous matrix on the compaction pore reduction is relatively obvious; the dissolution pore enhancement rate is negatively correlated with the content of semi-plasticity and weakly positively correlated with the content of tuffaceous matrix. The content of deformable compositions is negatively correlated with reservoir physical properties, with the fully plastic tuffaceous matrix having a weaker destructive effect on reservoir physical properties. The deformable compositions exacerbate the densification of the reservoir during compaction, and at the same time reduce the flow of diagenetic fluids, but the tuffaceous matrix completely fill the intergranular pore space after compaction, and the effect is more significant. The tuffaceous matrix as the solute of intergranular dissolution, its dissolution is also conducive to the improvement of the physical properties of the reservoir; when the content of the tuffaceous matrix ranges between 8%～12%, it is the most conducive to the formation of better quality reservoirs.

Abstract:

The Weining Beishan polymetallic mining area in Ningxia is one of the important metal mineral mineralization areas in Ningxia. At present, multiple ore deposits (points) have been discovered in the research area, including Jinchangzi gold mine and Errenshan lead silver mine. The Errenshan silver lead polymetallic deposit is a shallow low-temperature hydrothermal type and is currently the largest known silver lead polymetallic deposit in the region. With the further deepening of ore exploration in Errenshan, there is an urgent need for further in-depth research on ore exploration models and prediction in the area, in order to further expand the resources and exploration achievements. This article takes the Errenshan silver lead polymetallic deposit as the research object, uses short wave infrared technology (SWIR) to scan the borehole core, determine the types, relative content, and distribution characteristics of altered minerals in the core, and reveal the relationship between the changes in spectral parameters of altered minerals and mineralization intensity. The shortwave infrared technology is used to measure muscovite group minerals, kaolinite group minerals, carbonate minerals, montmorillonite group minerals, etc. Sericite group minerals and carbonate minerals are the through minerals of the borehole, kaolinite, montmorillonite, chlorite and sulfate minerals are only a small amount distributed in the borehole, and the altered mineral combination in the mineralization section is sericite+kaolinite+a small amount of carbonate minerals. By calculating the characteristic parameters of sericite Al—OH spectrum, it is found that the characteristic absorption peak of sericite Pos 2 200 nm and the IC value of sericite crystallinity have a good correlation with mineralization. In high-grade mineralized areas, the overlapping area of Pos 2 200(＜2 204 nm) and sericite crystallinity (IC value)>2.5 can serve as an important indicator or prospecting marker for exploring such deposits in Weining Beishan area.

Abstract:

Fused quartz crucible produced from high purity quartz (HPQ) sands is an essential material in which monocrystalline silicon ingot is grown by a process called the Czochralski process, and therefore plays an important role in solar photovoltaic cell and semiconductor industries. Almost all HPQ sands used for fused quartz crucible production in China come from overseas HPQ deposits in USA and India. Investigations on foreign HPQ ores with focus on impurities occurrences, beneficiation test, and resources potential evaluation are pivotal for HPQ deposits prospecting in China. In this study, I used a combination of multiple analytical techniques to conduct petrographic analysis, process mineralogical investigation and beneficiation test on a high purity quartz ore from northern India. My efforts reveal that quartz crystals from the ore material are relatively equant in size and largely devoid of liquid-gas inclusions. The existing liquid-gas inclusion assemblages predominately occur along grain boundaries of quartz crystals, and diffusive inclusion assemblages are extremely rare. Identified gangue minerals, in order of frequency, are Fe-bearing muscovite, iron oxides, ilmenite, zircon, monazite, brabantite, rutile, and mainly embedded among quartz crystals. Based on the impurities occurrence features of the Indian HPQ ore, refinement flowsheet composed of crushing-grinding, sorting, calcination, water quenching, high gradient magnetic separation, flotation, acid leaching, and hot chlorination was carried out, and end products were verified as 4N8 grade HPQ sands (total concentrations of 15 trace elements < 20×10^-6, SiO₂ content > 99.998%). By comparison with IOTA CG HPQ sands, the 4N8 grade HPQ sands extracted from the Indian HPQ ore were deemed to be used to produce outer layer of quartz crucible. Implications for HPQ ore prospecting in China deduced from this investigation practice on the Indian quartz-crucible-grade HPQ ore could be concluded as follows. Resources evaluation on potential HPQ ore in conjunction with process mineralogical study and beneficiation test is an essential prerequisite for deposits prospecting. Given the current political-economic environment, I recommend that the Chinese government designate the HPQ raw material as a unique mineral resource and enroll it on the National Strategic Mineral List. Subsequently, a general specification for HPQ ore exploration is needed with great urgency. In order to create domestic breakthrough on HPQ ore prospecting and resolve the dilemma that supply chain of HPQ sands used for solar and semiconductor industries relies heavily on USA and India, the domestic sections of HPQ deposits prospecting and exploration, HPQ sands extraction, HPQ products fabrication, and application end user should work collaboratively under the government organization and supervision.

Abstract:

The chemical speciation characteristics of heavy metals (As, Cd, Cr, Cu, Hg, and Pb) in soils along the banks of the Dawu River, Fuxi River, and Le'an River (Dexing section), adjacent to the Dexing copper mining area, were systematically investigated using the modified seven-step sequential extraction procedure developed by Tessier. The study focused on the concentration profiles, spatial distribution patterns, and inter-element correlations of these metals. The findings demonstrated a high degree of uniformity in the average distribution of specific chemical species across different heavy metal elements within the study area. The chemical speciation profiles generally exhibited a multimodal distribution pattern, with Cd, Cu, and Hg displaying pronounced spatial variability in their respective speciation. The maximum proportion of bioavailable fractions of As, Cd, and Cu was identified in soils from the Le'an River basin (Dexing section), while Hg and Pb reached their highest proportions in the Dawu River and Fuxi River basins, respectively. The bioavailable fraction of Cr showed negligible variability across the three basins. Statistically significant correlations were observed among the chemical species of Cu, Hg, and Pb, indicating notable interactions. The interconversion among chemical species was predominantly regulated by soil environmental parameters such as pH and Eh, which also played a critical role in determining the mobility and bioavailability of heavy metals. The study concluded that mining activities in the Dexing region are the principal contributors to heavy metal contamination in local soils. Consequently, remediation strategies for polluted soils in this area should prioritize managing the release and equilibrium of carbonate-bound and organic matter-bound forms to mitigate environmental risks effectively.

Abstract:

Bauxite-based mineral composites (BMC) with LiCl ·2 Al(OH)₃·n H₂O as the core component were prepared from natural bauxite and used for the separation and enrichment of lithium in deep brine of CXD 1 well. The adsorption and desorption properties of Li⁺ of BMC were investigated in simulated solution and real brine. The simulated Li⁺ solution adsorption results demonstrated that the adsorption kinetics were well simulated by the pseudo-second-order model, and the Langmuir model was compatible with the adsorption data, with a maximum Li⁺ capacity of 2.78 mg/g at 298 K. The results of the separation and enrichment study of Li⁺ in the deep brine of CXD 1 well showed that the adsorption rate of Li⁺ in the brine reached 86.38% at the dosage of 1.0 g/25 mL of BMC, and that Li⁺ was adsorbed with good selectivity in the presence of competing ions, such as Na⁺, K⁺, Ca²⁺ and Mg²⁺. After 5 times of adsorption and regeneration, the adsorption capacity decreased by 10.64%. After the removal of impurities by ion exchange resin, the Li⁺ in the eluate was enriched by Na₂CO₃ precipitation, and the Li₂CO₃ yield could reach up to more than 80%. The prepared Li₂CO₃ had comparable properties with commercial analytical purity Li₂CO₃. It can be seen that the BMC used in this paper had potential application in the extraction of Li⁺ from real brine.

Abstract:

To analyze the effects of microorganisms and clay minerals on the amount, mineral type, and mechanism of carbonate mineral precipitation, Cladosporium and illite, which can induce dolomite precipitation, were used as exogenous factors to simulate the conditions suitable for the survival of Cladosporium. The induced precipitation of carbonate minerals in marine solutions was investigated through an experiment, using a nutrient broth culture medium with Mg²⁺/Ca²⁺=8, at 30℃. The culture period was set to 1, 3, 5, 10, and 15 days. Following the culture, the pH value was recorded, and Mg²⁺ and Ca²⁺ concentrations were sampled and measured, whereupon the precipitates were collected for analysis via scanning electron microscopy, energy-dispersive spectroscopy, and X-ray diffraction to examine the effects of different precipitation systems on the precipitation of carbonate minerals. The experimental results revealed many types of precipitates underlying the microbial precipitation system, including high-magnesium calcite and micron-sized protodolomite minerals. In clay mineral precipitation, the precipitates comprised mainly high-magnesium calcite, calcite, and nanoscale protodolomite. In the co-precipitation system, where the results of multiple tests were similar to those obtained in the clay mineral system, the precipitates were primarily calcite and dolomite nanospheres, suggesting that clay minerals do not promote the formation of carbonate minerals induced by microorganisms. Therefore, as a microorganism, Cladosporium has a greater impact on the quantity and rate of carbonate mineral precipitation than illite, and this may be because microorganisms can continuously provide carbonate ions into the precipitation system solution, thus accelerating the precipitation of carbonate minerals.

Abstract:

To enhance the utilization ratio of silicon from potassium feldspar in the hydrothermal synthesis process of kaliophilite and address the issue of alkaline waste liquid produced by this process, this research carried out the filtrate recycling experiment in the hydrothermal synthesis system of potassium feldspar to kaliophilite. The effects of reaction time, reaction temperature, the molar ratio of SiO₂ to Al(OH)₃ and alkali concentration on Si utilization and product structure were discussed, as well as by investigating the reaction process. The effect of the number of cycles on the utilization ratio of silicon, the structure of the product and the stability of the process were investigated by the circulating experiment of the filtrate under the optimal conditions. The reaction mechanism was further explored and the process before and after the improvement was compared. The results demonstrate that when the reaction time was 4.0 h, the reaction temperature was 280℃, the molar ratio of SiO₂ to Al(OH)₃ was 0.8, and the alkali concentration was 12 mol/L, the utilization ratio of silicon in potassium feldspar could attain 94.2%, representing an increase of 60% compared to the process was improved. The product kaliophilite was homogeneous, superior quality and the recycling process was stable.

Abstract:

Vanadium and its compounds, as important strategic resources, are widely used in core fields such as metallurgy, chemical industry, aerospace, national defense and military due to their special physical and chemical properties. How to recover vanadium resources from vanadium slag in a low-cost, green and efficient manner, is an important measure to ensure the sustainable development of China's vanadium industry. This article systematically summarizes the current research status of major vanadium extraction processes at home and abroad, including roasting (non-salt roasting, sodium-roasting and calcium-roasting)-leaching (water-leaching, acidic-leaching and alkaline-leaching)-recovery (hydrolysis, ammonium precipitation, solvent extraction and ion exchange)-calcination, and looks forward to the future research directions of vanadium extraction processes to achieve high-efficiency, low-cost, and pollution-free green development of vanadium extraction processes.

Abstract:

Due to the insufficiencies of traditional sampling and quantitative characterization methods for oil shale formation, this paper proposed a new approach for rock classification and sample selection based on the study of the shale oil well section in the Mahu Depression. The approach combines dual-energy CT and MaipSCAN mineral scanning electron microscopy data and takes into account rock density, photoelectric index, and mineral identification. Clustering analysis is utilized for the classification. The proposed method is then applied to identify prevalent formations. An innovative representative rock sample selection method and process are introduced that considers macroscopic heterogeneity. The results show good consistency between the photoelectric index-density classification and minerals, and the clustering classification method is capable of further fine sample selection. Layers with high plagioclase content exhibit better oil and physical properties and can serve as geological and engineering sweet spots. The proposed classification method and sample selection process are reliable and provide new ideas and methods for the systematic evaluation of oil shale reservoirs.

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:

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:

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 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:

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:

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:

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:

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:

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:

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:

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:

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:

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.