Abstract:The Bikou volcanic terrane is predominated by tholeiitic marine lavas, with lower initial ratios of Sr and Nd, 0.701 248～0.704 413 and 0.511 080～0.512 341 respectively. Analyses also showed that most samples have negative εNd, which indicates that magma was probably derived from the mantle, while those with positive εNd perhaps resulted from magmatic contamination. In addition, rocks have significantly higher 207Pb and 208Pb. REE patterns and trace element spider diagrams indicate that magma generated by partial melting gave rise to some extent of differentiation during its evolution. Consequently, LREE and LILE demonstrated variation from depletion to enrichment.Besides, Basic lavas from the Bikou volcanic terrane showed the same characteristics as those from arcs in the background of subduction and collision with the consideration of ratios of Th/Yb, Th/Nb and Hf/Th. New evidence showed that the Hengdan group is a turbidite terrane filled in a forearc basin, and both the Bikou and the Hengdan groups construct an arc-basin system developed on the north margin of Yangtze plate. SHRIMP ages indicated that the arc-basin system developed in the Neoproterozoic.

Abstract:Using the 40Ar_39Ar isotopic chronological method to analyze K-feldspar from moyite in the Qiaohuote copper deposit, the authors obtained a plateau age of 274.78±0.44 Ma and an isochron age of 272.7±3.0Ma. As there existed no tectonic deformation and hydrothermal alteration in themoyite intrusive body after its rock-forming stage, the 40Ar-39Ar isotopic age should represent the crystallization age of the K-feldspar in moyite, i.e. the late crystallization age of the moyite intrusive body. Based on such factors as the spatial relationship between the moyite intrusive and the Qiaohuote copper orebodies, the variations of copper ore grade, the REE characteristics of the moyite and the copper orebody, and the H and O isotopic composition of fluid inclusions in the copper ores, it is held that the ore-forming process of the Qiaohuote copper deposit was related directly to the intrusive activity of the moyite, and therefore the crystallization age of the K-feldspar in moyite should approximately represent the lower limit of the metallogenic epoch of the Qiaohuote copper deposit.

Abstract:Dolomite marble and K-rich slate are two main sorts of rocks that host the Fe-Nb-REE orebodies of the Bayan Obo deposit in Inner Mongolia. Nevertheless, their protolith rocks and petrogenesis remain problems of much controversy. With 18 microphotographs, the authors illustrate the autometasomatism of the rocks and, on such a basis, try to demonstrate their petrogenesis. It is held that the protolith of the dolomite marble is magmatic carbonatite and that of the K-rich slate is trachytic volcaniclastic rock or volcanic tuff.

Abstract:It has been found through phase diagram analysis that the low-pressure metamorphic belt of Erlangping Group is a superimposed metamorphic belt. During the uplift of middle-pressure metamorphism, the low-pressure metamorphism took place. pT conditions of middle-pressure metamorhpism are 0.5～0.6 Gpa and 560～580℃. The pressure of low-pressure metamorphism is 0.3～0.45 GPa, and the temperatures of the andalusite-staurolite zone and the cordierite zone are 510～580℃ and 590～620℃, respectively. The pTpseudosection is a powerful tool for analyzing the pT evolutionary process and pT conditions when there exist several mineral assemblages formed in different periods and under different conditions.

Abstract:The Permian strata on the western margin of Ordos belong to strata of the pre-foreland basin. On the whole, the tectonic belts of foreland basin regionally control the diagenesis of sandstone, with different belts characterized by different diagenetic dynamical environments. The Permian high quality reservoir was formed in the western thrust belt and underwent weak compaction with shallow burial and dissolution. The sandstone pores of Permian strata on the slope belt are mainly composed of secondary pores resulting from strong dissolution, with a certain quantity of relict original pores. Great losses of sandstone original pores in the geotectogene resulted from the compaction and cementation with deep burial, whereas the reservoir quality was improved by dissolution and the sandstones served as the effective gas reservoir.

Abstract:Lacustrine laminae are mainly deposited in lake water with obvious layering. Such factors as temperature, salinity and depth control the water layering. Some materials like algae, carbonate, organic matter, clay and silty sand can separately form different laminae in different seasons. The deposition of algae and organic matter is related to seasonal blooming of algae, and carbonate laminae may be related to chemical or biochemical deposition due to the blooming of algae. Clay and silty sand are transported by stratified current. In any cases, however, the variation in the deposition of laminae is closely related to the change of climates. Much importance has been attached to the application of laminae to deduce the changes of climates and environments in the past. Nevertheless, researches on the changes of laminae and the development of lacustrine physicochemical properties on the basis of periodic changes of climate remain to be conducted.

Abstract:The primary jadeite jade orebody in the lenticular form intruded into the serpentinous ultrabasic rocks. Trapped massive bodies with composition of country rocks are distributed in the jadeite jade orebody. The order of crystallization in the orebody is coarse-prismatic jadeite with broom-like texture→fine-prismatic jadeite with interlocking texture→veins of macro-prismatic jadeite with flowage structure and granulous analcite→veins of analcite→veins of albite and quartz. The green jadeite jade, 0.06～0.08 mm in length and 0.01～0.015 mm in width, consists mainly of macro-prismatic jadeite with flowage structure. The orebody consists mainly of fine-prismatic jadeite with interlocking texture. It is held that the jadeite jade orebody was formed bythe evolution of ultrabasic magma during crystallization.

Abstract:The coloration machanism of Changhua Chicken_Blood Stone hasbeen discussed in this paper on the basis of X-ray diffraction analysis, SEM and electron microprobe analysis. The color of “Tianhuang Dong” is related to the isomorphism of such impurity elements as Fe3+ and Cr3+. The light red color of “Furong Dong" is caused by the isomorphism of Cr3+. The light green color of “Bohe Dong" and the purple color of “Zhusha Dong" are related respectively to the existence of illite and goethite.

Abstract:In this paper, the adsorption properties of micro-pore molecular sieves for Cu~(2+), Zn~(2+), Pb~(2+) and Cd~(2+) have been studied. Experiments show that under the condition of wide pH range, molecular sieves of 10 g/dm~3 and heavy metals ions of 60 mg/dm~3, the adsorption rates of MCM-41/ZSM-3 for Cu~(2+), Zn~(2+), Pb~(2+) and Cd~(2+) are higher than 90%. The regression equation indicates that the adsorption of Cu~(2+), Zn~(2+), Pb~(2+) and Cd~(2+) in the experimental concentration range is coincident with the single site Langmuir sorption and has remarkable adsorption capacity.

Abstract:The zircons from Mingxi of Fujian Province assumes colorless, grayish brown and light blue after heat treatment. A process of heating and irradiation was designed to tackle them. The colors and their variations were studied by UV-NIR spectrometer. The formation mechanism of the zircon colors were discussed on the basis of experiments. It is shown that the brown color of the zircon is caused by color-center, and that the light blue color is attributed to Fe~(2+)Fe~(3+) intervalence charge transfer, which contributes to the beauty enhancement of the zircons.

Abstract:The visible absorption spectrograms of 32 jadeite jade samples were measured by MPV-Ⅲ microphotometer, and their three-impulse values were calculated. On such a basis, the concept of color difference in even color space is put forward. By calculating NBS values of the samples, the color differences of the samples were analyzed quantitatively. It is shown that the quantitative calculations of color differences can present true colors of different samples and are different from the metamerism indexes. Therefore, this technique is a valuable means for identification of green jadeite jade and can play a very important role in gem identification.

Abstract:With such means as EMP, XRD, IR and SEM, the authors made a detailed study of Changhua Chicken-Blood Stone from the Limei mining area, Changhua County, Zhejiang Province. The results show that this variety of Chicken-Blood Stone is mainly composed of alunite together with a small amount of dickite and kaolinite.

Abstract:Powder X-ray diffraction analysis and Micro-Raman spectra were used to study the mineral composition of Chinese freshwater cultured pearls from Zhuji, Zhejiang Province. The results show that the pearls mainly contain aragonites, with some commercially useless pearls having vaterites in addition to aragonites. In pearls, the nacreous layers are generally translucent and composed completely of aragonite, whereas layers without pearly luster are opaque and composed of aragonites and/or vaterites with their relative concentrations different in different pearls. In conclusion, the freshwater cultured pearls produced by mussel Hyriopsis cumingii contain no calcites, and this is obviously different from characteristics of saltwater cultured pearls.