Abstract:Zircon U-Pb age, major and trace elements, REE, Sr-Nd-Pb, and zircon Hf isotope compositions were discussed for the Mesozoic Tongjing diorite porphyry in Yinan area of western Shandong Province. The results show that the Tongjing diorite porphyry is characterized by high SiO₂ (54.68%～63.01%) and Mg(Mg^#=55～66) and relatively low TiO₂ (0.2%～0.71%) content, similar to high-Mg diorite distributed extensively in western Shandong Province. There is a strong enrichment of LREE [(La/Yb)_n=10～15] and HFSE (Nb, Ta, Ti) anomaly, with no Eu anomaly, and Sr (241×10^-6～711×10^-6) and Ba (554×10^-6～822×10^-6) content is high. The Sr-Nd isotope characteristics of rock resembling suggest that they have the same magma source. The I_Sr and εNd(t) values are respectively 0.706 473～0.708 867 and -15.13～-9.18, which are not consistent with the data of contemporaneous Yinan gabbro which had been studied by the former researchers. Available isotopic data of the Tongjing diorite porphyry reveal that the major magma sources were enriched lithospheric mantle. Besides, magma from the lower crust and depleted mantle is also important, and Pb isotope shows that the lower crust was formed by North China Craton and Yangtze Craton. Zircon U-Pb age is 128～129 Ma, which is an embodiment of Mesozoic large-scale magmatic activities in east NCC, and the age is similar to that of Mesozoic intursive rock of Jiaodong area, indicating that the two areas might have the same background for magmatic activities. The εHf(t) values range mainly from -13 to -8 with a mean value of -10.3, also implying that the magma came from enriched lithospheric mantle mixed with depleted mantle. The variety of multiple magma sources and the progressive participation of depleted mantle components in response to the lithospheric thinning reached the max in late Mesozoic in the eastern part of North China Craton. The different sources of magma might have been the main factor responsible for mineralization between Jiaodong peninsula and western Shandong Province.

Abstract:The Keshuling-Xian'etang greisen-quartz vein type tungsten-tin polymetallic deposit located in Chongyi County of Jiangxi Province is one of the medium-sized tungsten polymetallic deposits in South China. It is closely related to felsic Keshuling granite outcropped in South mining area. SHRIMP zircon U-Pb dating of a fresh granitic sample from the drilling core has yielded ages of 251.5±6.6 Ma and 202±15 Ma. The Keshuling granites fall into the peraluminous, high-K and calc-alkali category revealed by whole rock analysis. SiO₂, total alkaline (Na₂O+K₂O), Fe₂O₃ and FeO contents of the Keshuling granitic intrusion are 73.51%～74.23%, 6.58%～7.77%, 0.01%～0.07% and 0.49%～0.95% respectively. K₂O/Na₂O and A/CNK ratios of the Keshuling granitic intrusion are 1.05～1.98 and 1.17～1.60 (>1.1) respectively. The low REE total content (ΣREE=43.98×10^-6～80.16×10^-6) demonstrates intense differentiation and crystallization at the petrogenic stage, which is the characteristics of typical Nb and Ta-bearing granites in South China. The (La/Yb)_N and δEu of the Keshuling granites are 2.53～7.80 and 0.09～0.20 respectively. According to chondrite-normalized REE patterns, the REE of the Keshuling granitoids have "tetrad effect". Granites and pegmatites of "tetrad effect" are crystallization products of residual melting at the last stage of granitic magmatism. Intensive fractional crystallization can result in enrichment of volatile matters (H₂O, F, Cl, B, P), alkali metals (Na, K) and some ore-forming elements (REE, Nb, Ta, Li, Be) in residual melt. In the primitive mantle-normalized trace element spidergram of the Keshuling granites, defective values of Sr, Eu and Ti show that there existed crystallization and separation of feldspars and ilmenites. The ¹⁷⁶Lu/¹⁷⁷Hf and f_Lu/Hf ratios of zircons in the Keshuling granitic intrusion are 0.000 373～0.003 818 and -0.99～-0.88 respectively, which are lower than those of the upper crust. The ¹⁷⁶Hf/¹⁷⁷Hf ratios (0.281 819～0.282 600), εHf(t) values (between -14.5 and -1.3) and T_DM2 (3.21～2.55 Ga) are representatives of an Archean crustal reservoir. Ca/(Mg+Fe)-Al/(Mg+Fe) diagram indicates that Triassic granitoids in South China mainly originated from metagreywackes and pelites, with the involvement of a small amount of metamorphic basalts and tonalities. Two positive εHf(t) values (+2.4 and +3.0) of zircons indicate that mantle sourced zircons were captured during the elevation and emplacement of felsic magma. Compared with previous achievements, it is suggested that the Triassic granitic rocks including the Keshuling granites in South China were formed in a post-collisional tectonic setting or at the late stage of syn-orogenic tectonic setting. During the relaxation after extruding process, the felsic magmas were fomed by partial melting of thickening crustal materials.

Abstract:Located in Zhongdian island arc belt in northwestern Yunnan Province, the Pulang superlarge porphyry copper deposit was formed in late Triassic during the westward subduction of the Ganzi-Litang ocean plate below Zhongdian microplate. The mineralized rocks of the Pulang porphyry copper deposit mainly include quartz dioritic porphyries and quartz monzonitic porphyries in a complex pluton, and economic ores are mainly preserved in the quartz monzonitic porphyries. The quartz dioritic porphyrites were intruded by later quartz monzonitic porphyries, but the two kinds of rocks display similar geochemical characteristics, such as similar REE patterns, incompatible trace element patterns and initial ⁸⁷Sr/⁸⁶Sr and ¹⁴³Nd/¹⁴⁴Nd ratios, suggesting that they were cogenetic products or were derived from similar sources. Geochemically, both kinds of rocks are akin to adakite, as evidenced by such characteristics as high Sr content (289×10^-6～1 200×10^-6), high La/Yb and Sr/Yb ratios, relatively high MgO and Mg^# (>59), depleted Y and Yb, slightly negative Eu anomalies and positive Sr anomalies. Moreover, the radiogenic Sr [0.705 60<(⁸⁷Sr/⁸⁶Sr)_i<0.705 74] and less radiogenic Nd [-2.85<εNd(t)<-2.20] isotopic characteristics, together with high Th/Y, Ba/La, Rb/Sr, and Ba/Sr trace elements ratios, imply that enriched source components were involved during the formation of the porphyries. This enriched source was probably derived from the basement of arc crust or subducted sediments, and then some mixing processes possibility occurred between adakitic magmas and melts from sediments and/or arc crustal materials. A comparison between the quartz dioritic porphyrites and quartz monzonitic porphyries suggests that the former have low SiO₂ (>61.0%) and K₂O (2.2%～4.4%), while the latter have high SiO₂ (>65.9%) and K₂O (3.5%～8.1%). Therefore, the authors hold that the Pulang porphyry copper deposit was probably related to the westward subduction of Ganzhi-Litang oceanic plate during late Triassic. At the early stage of subduction, the quartz dioritic porphyries with subduction-related origin were formed firstly, then increasing adakitic magmas of slab melting were mixed with melts from subducted sediments or arc materials, producing more acid and high oxygen fugacity adakitic magmas, which finally intruded the upper crust below Pulang and promoted the mineralization of the Pulang porphyry copper deposit at the shallow level.

Abstract:Located on the southeast coast of Fujian Province, Taimushan granite was formed as a result of the interaction between the Pacific plate and the Eurasian plate during the late Mesozoic. Field work and petrographic analysis show that granite rocks are extensively distributed in this area, and most of them are K-feldspar granite. Rocks mostly show subhedral granular texture and typical micrographic texture, and the main minerals include alkali feldspar (mainly perthite and subordinately a small amount of microcline) and quartz, with very rare dark minerals. The SiO₂ content of rocks is in the range of 76.93%～79.47%, the total alkalis content (K₂O+Na₂O) is in the range of 7.47%～8.88%, and the K₂O content of most rocks is higher than Na₂O content. A/CNK ratios are in the range of 0.95～1.01, TFeO/MgO ratios are in the range of 8.11～17.83, and the differentiation index is in the range of 96.79～98.11. On the whole, the rocks are characterized by high silicon, enrichment of alkali, low calcium and magnesium, and high differentiation index, thus belonging to high-K calc-alkaline and metaluminous to weakly peraluminous granitoids. The rocks have high and remarkably varying REE, ranging from 94.98×10^-6 to 446.85×10^-6; LREE/HREE ratios range from 3.71 to 17.47, and (La/Yb)_N range from 3.8 to 10.53. δEu values range from 0.08 to 0.80, and their distribution patterns show LREE enrichment with gentle right oblique deviation, relative flat HREE and a seagull model characterized by significant negative Eu anomaly, suggesting characteristics of A-type granitic rocks. Most of the granites are strongly enriched in Rb, U, Th and La and considerably depleted in Ba, Sr, P and Ti. 10⁴ Ga/Al ratios are distributed between 2.74 and 3.46 (3.14 on average), which are higher than the 10⁴ Ga/Al low limit ratio of A-type granites in the world. The trace element spider diagrams of the granites generally show four V-shaped valleys for Ba, Sr, P, Ti depletion, similar to trace element spider diagrams of the Nanling granites. Zircon LA-ICP-MS U-Pb dating result indicates that Taimushan granite, whose diagenetic age is 96.6±1.6 Ma (MSWD=0.65), is the product of magmatic activity in late Yanshanian period. Its petrogenic age is similar to rock-forming ages of the adjacent Sanshao (91.5±1.5 Ma), Dacengshan (93.1±2.4 Ma) and Nanzhen intrusive bodies (96.1±2.7 Ma), suggesting that they may be products of the same magmatism. Petrography, geochemistry and discrimination diagrams show that the Taimushan granitoids belong to A-type granite with metaluminous to weakly peraluminous characteristics. Magma originated from partial melting of crustal materials, probably with the participation of a small portion of mantle materials. Integrated with multiple geochemical diagrams, field geology, regional background and geochronology, it is inferred that the granitic rocks of this area were formed in a post-collision and tensile tectonic environment. Between early and late Cretaceous, the continental margin of southeast China was constantly stretching, resulting in a large number of magmatic activities, and hence A-type granites were formed in Taimushan area under this background.

Abstract:Located in North Qinling, the Wuguan intrusive body intruded into the Danfeng Group and developed gneissosity in some regions. It mainly includes diorites and granodiorites and belongs to low-K tholeiitic and medium-K calc-alkaline series, characterized by enrichment of large ion lithophile elements and depletion of high field strength elements, with a high LILE/HFSE ratio. Geochemical data also suggest the involvement of a subduction sedimentary source. All the evidence indicates that the formation of the rock was associated with the ocean subduction. Chondrite-normalized REE patterns show an enriched LREE distribution and a flat HREE distribution, with no obvious negative Eu anomaly. Moreover, the Wuguan intrusive rocks are rich in sodium and aluminum, and have high Sr/Yb and CaO/Na₂O ratios. These geochemical features suggest that these rocks were formed by the remelting of the basaltic rocks with amphibole as a stable residual phase. The result of simu- lation calculation suggests that plagioclase amphibolite produced in an island-arc environment in the Danfeng Group could form the Wuguan intrusive body through partial melting with a degree of 30%～40%. Besides, the residual mineral assemblage is mainly hornblende with a small amount of plagioclase and clinopyroxene, and garnet-bearing residues may be negligible. CL images and LA-ICPMS dating show that zircon U-Pb isotopic age of the Wuguan intrusive body is 438.6±2.2 Ma, and the formation of this intrusive body might be attributed to Caledonian collision event of the North Qinling. This zircon U-Pb isotopic age is later than the period of the subduction of Shangdan Ocean, but the chemical characteristics of this intrusive body are closely related to the island-arc environments. It is therefore inferred that the geochemical characteristics reflected in the Wuguan intrusive body might have inherited some chemical features of its sources in an arc environment. Combined with the REE simulation calculation by the melting of the amphibolites formed in an arc environment, it is proved that the Wuguan intrusive body was formed in a collision orogenic process and it might have been a partial melting product of the pre-existing source in a subduction environment.

Abstract:Mylonites in the Dabie orogen are fault and shear zone related rocks formed under metamorphic conditions. They can be divided into greenschist, amphibolite, granulite, and eclogite facies mylonites. The main criterion for identifying the mylonites in the Dabie Mountain is the ductile (plastic) deformation of index minerals of the constituent metamorphic facies. This is clearly different from the former definition and description of mylonite. Formation epoch of the mylonites in the Dabie Mountain was approximately the same as (or a little later than) that of peak metamorphism of their host rocks. From older to younger, the series follows the order eclo- gite facies mylonite→granulite facies mylonite →amphibolite facies mylonite→greenschist facies mylonite. According to lithology and texture, the mylonites can be further divided into second and third subclasses if necessary. Former mylonites of eclogite and granulite facies are always superimposed by the later facies and show the appearance of amphibolite or even greenschist facies mylonites; the earlier formed mylonites are thus preserved as relics in their retrograded products. Mylonites in the low-grade metamorphic rocks in southern and northern Dabie Mountain only experienced the metamorphic history of greenschist and amphibolite facies mylonitization during the Paleozoic-Triassic period.

Abstract:The Longtoushan polymetallic sulfide deposit is located on the east slope of the middle-south Da Hinggan Mountains and the north side of the Xar Moron River fault along the Hercynian geosyncline fold belt. Field geological survey shows that the ore deposit has two mineralization types, namely layered mineralization and cylinder mineralization. Attitudes, alterations and minerals of the two mineralizeation types show typical characteristics of submarine hydrothermal sedimentary deposition. A systematic study of fluid inclusion petrography and microthermometry was carried out for fluid inclusions in syndepositional barite from the ore deposit. The inclusions in the barite suggest rapid sedimentary characteristics during the hydrothermal sedimentary deposition. Except for secondary fluid inclusions, gas-pure and gas-rich inclusions related to the mineralization are very rare, with the majority being liquid-rich inclusions. Microthermometric analysis shows that the liquid-rich inclusions have homogenization temperature 101.4～279.9℃, freezing temperature -5.5～-0.3℃, salinity 0.5% ～8.5%, and fluid density 0.75～0.97 g/cm³. Reflective features such as temperature, salinity and density of the ore fluids are consistent with features of the inclusions developed in submarine hydrothermal sedimentary sulfides ore deposits. The results provide positive evidence for the viewpoint that the Longtoushan polymetallic sulfide ore deposit is a marine hydrothermal sedimentation deposit.

Abstract:Since the late Paleozoic, the south Tianshan Mountain has gone through a series of collision and micro-plate collage events, which have had obvious reflection in the sedimentation and tectonic evolution of northern Tarim basin. The analysis of depositional provenance is an important method for understanding basin evolution and interpreting tectonic background, and is also the first prerequisite for confirming the evolution of the basin. The variation in the composition of depositional provenances reflects the relationship between the uplift of basin margin orogen and the basin subsidence. With the improvement of modern analytical techniques, the provenance analytical methods have increased in number, become gradually perfected in quality and complemented each other. Based on Dickinson's provenance analytical method, the authors studied and analyzed sandstone detrital composition and source rocks of Upper Carboniferous sandstone along different geological sections in northern Tarim basin. The results show that the major types of the Upper Carboniferous sandstone are quartz sandstone and lithic quartz sandstone, with low compositional maturity, and the average Q/(F+L) in Cedaya, Dashankou hydropower station and Bayinbuluke geological section are respectively 1.80, 3.11, 3.32. The detrital composition is mainly quartz and subordinately feldspar and some rock debris, with minor organic matrix or biotite. According to the study of sandstone detrital compositions, sandstone of Upper Carboniferous Ayilihe Formation in northern Tarim basin is composed averagely of 70.7% quartz (53%～86%), 7.1% feldspar (5%～17%), and 22.5% rock debris (20%～30%). Metamorphic debris and sedimentary debris are mainly existent in this area,while in Cedaya, volcanic debris possesses 42%. On the basis of Dickinson's triangular plot and the characteristics of rock debris, the Upper Carboniferous provenance in northern Tarim basin is characterized by the recycled orogen type, and the primary attribute is the suture zone for subduction and collision orogeny, with minor arc orogenic attributes. In combination with the late Carboniferous lithofacies-paleogeography of northern Tarim, it is held that the source of the northern Tarim basin might have been derived from the ancient Tianshan orogenic belt in the north.

Abstract:Geochemical characteristics of detrital sandstones provide an extremely important trace and indication for provenance, paleoclimate, depositional environment and properties of source rock. On the basis of field geological investigation, the authors studied the characteristics of trace and rare elements of the sandstones and probed into the features of depositional environment, paleoclimate and provenance by analyzing the change of the trace and rare element components of the sandstones. Sampling was conducted along the section of well-developed outcrops, and the weathered and altered samples were rejected under a microscope. The trace element content of sandstone samples collected from Gonjo Formation was determined by inductive coupling plasma mass spectrometry (ICP-MS). The sedimentary environment and properties of the source region of the sandstones in the Gonjo Formation were also investigated by means of ratios of Sr/Ba, Ce/Ce^*, Th/Sc, Th/U and La/Th as well as graphic interpretation of depositional structure background and cross-analysis of such multiple parameters as La/Sc-Co/Th, Th-Hf-Co, Th/Sc-Sc and La/Yb-∑REE. The results show that cerium was subjected to deficiency, and that the physicochemical properties of water bodies belonged to the oxide environment, because the ratio of Ce/Ce^* is between 0.80 and 0.93, and the index of Ce_anom is between -0.34 and -0.5. The values of deep source elements in trace elements are lower than the average value of earth crust claystone, which indicates that the sources of sediments were mainly derived from terrestrial material. Terrestrial elements and the average of earth crust clayrock are evenly matched, which reflect high deposition rate. The ratios of trace elements show obviously that the sedimentary environments were of fresh water quality, oxidizing environments and arid torrid climate during the period of the deposition of Gonjo Formation in the Paleogene basin, with the further deposition of the sediments consisting of salt, gypsum and marl. The LREE content is obviously enriched in comparison with the HREE content, with negative Eu anomalies shown in the chondrite aerolite standard pattern of sandstone of Gonjo Formation. However, the LREE content is slightly enriched, with indistinct Eu anomalies shown in the North American shale standard pattern of sandstone, which suggests that the depositional environment was an oxidizing environment with typical sedimentary characteristics. Based on an analysis of the ratios of trace elements such as Th/Sc, Th/U and La/Th as well as an analysis of such diagrams as La/Yb-∑REE, the authors have arrived at the conclusion that the diverse sources mainly came from felsic source region of the upper crust, and that their original rocks were sedimentary rocks, acid volcanic rock and tholeiite.

Abstract:Huizhou depression is one of the most prolific hydrocarbon areas in Pearl River Mouth basin. Plentiful Neogene oil and gas have been found, but no breakthrough has been made in Paleogene sediments. Reservoir porosity and permeability are thought very low in Paleogene, and this inhibits the exploration progress. As to the deep reservoir, the factor of porosity is in connection with petrographic composition and architecture. The skeleton components and matrix components of the sandstone are basic substances participating in diagenesis. Feldspar sandstone, feldspathic quartz sandstone and lithic arkose are main rock types in Zhuhai and Enping Formations, which are characterized by coarse grains, poor grading, subangularity, low compositional maturity, and moderate to bad textural maturity. The storage capability is considerably impacted by diagenesis and porosity evolution. Based on slices observation and cores analysis and using such means as scanning electron microscope (SEM), X-diffraction, cathodoluminescence and organic acid test, the authors studied diagenesis and porosity evolution. The results show that the sandstone porosity is decreased mainly by compaction and cementation and subordinately by quartz overgrowth and authigenic mineral filling. Abundant secondary pores are produced by the denudation of such unstable components as feldspar, matrix and cuttings, and this leads to the increase of the percentage of voids.Researches reveal that the deep reservoir has experienced four diagenesis evolution phases, i.e., syngenetic stage, eogenetic stage (composed of A-stage and B-stage), anadiag enetic stage (comprizing A-stage & B-stage) and late diagenetic stage. Well data show that most of the reservoirs have attained the eogenetic stage,whereas segmental sandstone (under 4 000 m) has entered into the late diagenetic stage. Primary porosity was decreased quickly by compaction at the eogenetic stage (A→B) because of the increasing overlying load. Linear contact occurred at the B-eogenetic stage. Hydrothermal fluid of organic acid was discharged to fastigium with most kerogen being transformed into hydrocarbon at the anadiagenetic stage (A→B). Due to increasing acidity, the unstable components of aluminosilicate framework ingredients such as feldspar, matrix and cuttings were dissolved, so a lot of secondary pores were generated, and the physical property of reservoir was improved. At the late diagenetic stage, organic material was changed from mature to highly mature, organic acid concentration was decreased to the lowest and destroyed by thermal activity, stratigraphic water was gradually turned into alkaline, authigenic minerals were developed generally, and the reservoir physical property was changed to bad by the cementation of anhydrite. Just because lots of secondary pores were generated at the eogenetic stage, it improved the physical property and increased the potential of deep reservoir exploration.

Abstract:Although Dasanjing basin group is a residual basin at present, there existed a huge oil and gas potential in the uniform lake basin in Early Cretaceous, especially in the Chengzihe and Muling Formations, which now serve as important exploration strata. Based on mathematical statistics and Q type cluster analysis, the authors analyzed the heavy mineral ZTR indexes, stability coefficients and assemblage characteristics of the sandstones from Early Cretaceous Chengzihe and Muling Formations distributed in 20 drill holes in the main basins of Dasanjiang basin group, and then determined the direction of the provenance. The heavy mineral ZTR index contour maps of Chengzihe and Muling Formations are characterized by the gradually increasing trend from the edge towards the center, while their heavy mineral stability coefficients are relatively low, reflecting a lower heavy mineral stability at the early stage of the basin formation. According to the heavy mineral distribution, the study area can be divided into 6 heavy mineral assemblage zones. A comprehensive analysis shows that the provenance directions of Chengzihe and Muling Formations in Dasanjiang basin group did not change significantly, and both of the formations actually had an inheritance relationship. There mainly existed three provenance systems: the west and northwest provenance from Xiao Hinggan Mountain-Zhangguangcai Mountain, the east provenance mainly from Baoqing Block and Dongsanjiang uplift area and the southeast provenance mainly supplied by Xingkai Block. Nadanhada Block and Yanji fold belt provided source materials for northern Hulin Basin and southern Jixi Basin respectively, but the influence was limited.

Abstract:"Dolomite problem" has long been one of the focuses and difficulties in the study of sedimentary geology. Dolomite serves as an important reservoir of oil and gas both in China and abroad. Therefore, the understanding of the formation process of dolomite is significant for the exploration of oil and gas in carbonate rocks. There are many models to explain the origin of dolomite, such as the Sabhka evaporation model, the seepage-reflux model, the burial adjustment model, the mixing zone model, and the tidal pumping model. During the past decades, with the further research on the dolomite formation at low temperature, the microbial dolomite model, as a new dolomite origin model, was proposed and well developed. This paper reviews the progress of research on microbial dolomite. Three kinetic barriers of dolomite precipitation under earth surface conditions were listed, which are strong hydration energy of magnesium ion, the existence of sulfate ion and the low concentration and low activity of carbonate ion. The background for putting forward the microbial dolomite model and the growth process and morphological characteristics of microbial dolomite were briefly described. The mediation of microbe during the formation process of dolomite was explained in detail. It is pointed out that the existence of microbes (e.g., sulfate-reducing bacteria and ancient methane bacteria) could change the ion balance of solution and help dolomite to overcome the kinetic barriers during the precipitation process. The application of oxygen isotope of microbial dolomite to the reconstruction of palaeo-temperature and ancient climate change was discussed. The future orientations for research on microbial dolomite (e.g., multidisciplinary analysis, application of high technology etc.) were predicated. The further investigation into the microbial dolomite model will provide researchers with a new approach to understanding the "dolomite problem" and is also helpful to the study of dolomite reservoir in petroleum geology.

Abstract:Extensive investigations into diamond classification, growth structure and impurity have been performed by scientists, but rare studies have been devoted to the diamonds with mixed types. Using DiamondView and FTIR microscopic regional scanning techniques, the authors found that one of the sixteen diamonds collected in 50^# pipe in Liaoning displays both ⅠaB and ⅠaAB types simultaneously. The boundaries between ⅠaB and ⅠaAB types are clear. In DiamondView UV-fluorescence images, the diamond displays an irregular circle-like growth zoning, which could be divided into two growth stages, i.e., early nucleation stage and late growth stage. At the early nucleation stage of the diamond, the growth ring is not apparent and there is no multiple growth center. At the late growth stage, the concentric circling structures is obvious, with clear boundaries between various envelops and uneven fluorescence colors. the shape and intensity of absorption peaks, obtained by the FTIR microscopic regional scanning spectra, are continuously variable. The infrared spectra have basic identical features at the same growth stage, except for the difference in absorbing intensity. The infrared spectrum characteristics are divided into two types, ⅠaB and IaAB , at different growth stages. Pseudo-color mapping of concentration distribution related to total nitrogen and a pair of atoms nitrogen and hydrogen has been obtained by OMNIC Picta. The results of DiamondView and FTIR microscopy regional scan can be mutually validated from center to edge of the diamond, and the change in nitrogen and hydrogen concentrations corre-sponds to two stages observed by the DiamondView image. Based on the study of the variations of nitrogen and hydrogen of the diamond, the authors hold that the growth environment of the diamond underwent apparent changes with a clear growth pause between the two stages and, as a result, A centers could not be completely transformed into B centers at later growth stage. The consumption of nitrogen and hydrogen was remarkably at the nucleation phase, and they were almost completely consumed at last, then the crystal growth stopped until the surrounding environment changed. With the complement of nitrogen and hydrogen, the diamond continued to grow. It is also shown that the concentrations of nitrogen and hydrogen might have played an important role in nucleation. Under low saturation, the growth of diamond might be slower or even stopped. The discovery of this kind of diamond is of great significance in the study of geological environment changes during diamond growth processes.

Abstract:The concentration and distribution of trace elements in 144 coal samples from the Zhangji mining area were studied. Compared with average concentrations of trace elements in coals from China and abroad, the coal from the Zhangji mining area contains higher concentrations of B, Se and As. Vertical variations of trace elements in seven coal seams indicate that the distribution of trace elements in coal seams has some regularity; especially in No. 9 coal seam, Ba and Cr values are minimum while Mn, Zn, As and Se values are maximum. On the basis of these distribution characteristics of trace elements, the elements Mn, Zn, Se, Ba and Cr can be used as indicators for division of coal seams in the Zhangji mining area.

Abstract:The style, decoration and inscription of the bronzes have been studied for determining the foundry area of the bronze vessels, which is subject to the subjective experience and knowledge of archaeologists. Some scholars have analyzed lead isotope and trace elements of bronze vessels and attempted to ascertain the foundry area of the bronzes using natural science means. However, the signature of lead isotope and trace elements of the bronzes provide information on ore sources whose metal minerals were used to cast the bronzes, not the information on the foundry area. The composition of casting clay core might provide clue to the foundry area of the bronze vessels. This paper probed into the casting place of the bronze vessels on the basis of an analysis of clay core residues of the bronze vessels. Samples of the fragments of the casting clay cores were removed from the bronze vessels unearthed at Jiuliandun tombs of Chu State, in Zaoyang City, Hubei Province, dated back to the Warring States Period, and were analyzed by such means as polarized light microscope, XRD, XRF, NAA and ICP-AES. The results reveal that the casting clay cores of extraneous bronze vessels from Jiuliandun tombs are different from those of local bronze vessels excavated in No. 1 and No. 2 Jiuliandun tombs in such aspects as phase composition, microstructure, major elements, trace elements, REE and phytolith assemblages. The content of CaO in casting clay cores of extraneous bronze vessels is very high and the content of Na₂O is low, which are representative characteristics of the loess in northern China. Combined with the analysis of phytolith assemblages, it is inferred that extraneous bronze vessels were cast in the loess area of northern China. This study also indicates that it is feasible to restrict the possible foundry area of the bronze vessels according to the analysis of casting clay cores residues on the bronzes.

Abstract:The inorganic anti-bacterial material of metal ions type is characterized by high security, great anti-bacterial capability, wide working temperature range and heat-enduring properties, and hence it is used in many fields with extensive application value. It consists of two parts, i.e., anti-bacterial metal ions and inorganic carrier materials, and its anti-bacterial properties bear a relationship with the adsorption capacity of metal ions on the carrier material. This paper made a tentative study of two different processes, i.e., the acid modification of sepiolite and sepiolite loading anti-bacterial Zn²⁺, observing the influences of these two means on the structure of sepiolite and the amount of Zn²⁺. AAS, XRD, SEM/EDX, FT-IR were used to characterize the Zn²⁺-loading sepiolite, The results show that the utilization of 5% HCl at the temperature of 70℃ to treat sepiolite is a very necessary and effective means for improving the purity, scattering fiber bundles and expanding the pore space of sepiolite so as to increase the capacity of Zn²⁺-loading. Dry wet cycle way could be employed to enhance the capacity of loading Zn²⁺, but its complex operation and greater energy consumption hinder it from further use. Therefore, an appropriate choice is necessary.

Abstract:Blast-furnace slag was used as an active addition of magnesium phosphate cement. The influence of blast-furnace slag on the setting time, mechanical property, mineral phase and microstucture of slag blended magnesium phosphate cement (MPC) was studied. The prescription was designed as follows: the ratio of monoammonium phosphate to magnesia was 25% in mass, the borax additive amount to magnesia was 7.5%, the additive amount of blast-furnace slag was 0%, 10%, 20%, 30% and 40% separately in the ratio of total amount of dead burned magnesia and monoammonium phosphate to MPC. The results show that slag might participate the hydration, which improves the bonding of MPC, and the compressive strength of slag-blended MPC is improved with the increasing additive amount of slag. However, slag might results in expansion stress during hydration process, which causes lattice disturbance in hardened MPC, so the flexual strength decreases with the increasing additive amount of slag at the same time. The main hydration product of slag blended MPC is struvite (MgNH₄PO₄·6 H₂O), the content of amorphous phase might increase after being mixed with slag in MPC, and Ca²⁺ ions in slag can result in solid solution in the crystal lattice of struvite, which changes the microstructure and size of the hydration product. There is also much magnesia and slag powders subjected to no reaction in the hardened cement, which can be used as aggregates.

Abstract:Geopolymer is a kind of three-dimensional network structure from non-crystalline to half-crystalline inorganic polymer, synthesized by using aluminosilicate minerals or solid wastes and alkali-activate agent at 20～200℃. This paper has mainly studied the rapidly synthetic condition of geopolymer and its resistance to acid and alkali. Orthogonal experiments L₉(3⁴) of the raw material proportion of geopolymer were carried out, with the calcination temperature of kaolin, added content of kaolin, water glass and sodium hydroxide as the variable quantity. The optimum raw material proportion is that kaolin is calcined at 600℃ for 4 h, with the mass proportion of kaolin, water glass and sodium hydroxide being 7∶4.5∶1, and the early compressive strength is the highest: 62.25 MPa. On the basis of the optimal raw material proportion, the orthogonal experiments L₉(3⁴) for the preparation condition of geopolymer were conducted, with solidification temperature, curing temperature and curing time as the variables. The optimal condition was that the mixture was solidified at 60℃ and then cured at 60℃ for 1 h, in which the early compressive strength of geopolymer was 85 MPa. Geopolymer in 0.5 mol/L HCl, H₂SO₄ and NaOH solution was soaked for 60 h, mass changes were -2.03%, -5.33% and 2.90%,respectively, the compressive strength changes were -12.68% and 17.07%; When geopolymer in 0.25～1.0 mol/L acid and alkali solution was soaked for 24 h, with the increasing concentration, its mass and compressive strength increased in NaOH solution, changed insignificantly in HCl solution, and were significantly reduced in H₂SO₄ solution. The results show that the geopolymer can well resist HCl but its resistance to H₂SO₄ is poor, while NaOH can promote the compressive strength development of geopolymer.

Abstract:There are 208 species of minerals first found in Canada. Among them 118 species were originally named after localities and persons. The current Chinese names of these minerals mostly were translated and named after chemical compositions characteristics. The Chinese naming for these minerals does not follow the description by original authors and the general guidelines for mineral nomenclature by IMA-CNMNC. According to the spelling rule, the recommended Chinese names are listed for the 118 mineral species with the English names, original naming rules, existing Chinese names, and recommended Chinese naming.

Abstract:A comprehensive summary of the definition, mode of occurrence and remaining problems in the studies of C-type adakitic rocks is given in this paper for better understanding the implications of C-type adakite rocks in East China. It is pointed out that C-type adakitic rocks are high-K calc-alkaline and are likely derived from partial melting of intermediate- to high-K meta-andesitic-basaltic rocks under the high pressure condition. Unlike things of O-type adakite, the origin, source rocks and partial melting processes of C-type adakite remain unclear and hence more experimental work may have to be involved in future work.

Abstract:The anion exchange resin Bio-Rad AG1-X8 can be used to separate Mo from matrix elements in black shale and other geological samples. Most matrix elements, such as Fe, Ca, Na, Mn, Mg, Sr, Al, Cu and K, were eluted firstly by 1 mol/L HF+0.5 mol/L HCl; then Ti and Zr were eluted by 4 mol/L HCl; and Mo was eluted lastly by 3 mol/L HNO₃. Sr, which leads Mo isotope fractionation when Mo isotopic composition is analyzed by MC-ICP-MS, can be separated completely from Mo. During the eluting, most Mo was eluted within the first 5 mL HNO₃; the heavier Mo isotopes were collected first, then the lighter ones, so the eluant must be collected completely to avoid Mo isotope fractionation. When the amount of Mo in sample is large enough (≥50 μg), "column matrix effects" can be neglected and the Mo isotopic composition is unchanged after ion exchange separation, so the separation method is suitable for both sample-standard bracketing and double spiking techniques to calibrate the instrumental mass bias; nevertheless, due to "column matrix effects", this method is suitable for double spiking only when the amount of Mo is small (<50 μg).