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REE AND Sr, Nd, Pb ISOTOPIC GEOCHEMISTRY OF HUANGYISHAN BASALT, KUANDIAN, LIAONING, NORTHEAST CHINA 总被引:1,自引:0,他引:1
In the light of major element geochemistry, mineral chemistry and REE and isotopic data, the small but apparent isotopic differences between the Cenozoic volcanic rocks east and west of the Tancheng-Lujiang fault are believed to be caused by the mixing and metasomatism of crustal and mantle material in tho mantle source region in response to Pacific plate subduction. The presence of phlogopite and pargasite in mantle xenoliths lends strong support to mantle metasomatism. 相似文献
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High pressure/temperature annealing experiments are used to determine diffusivities of H+ and D+ in non-stoichiometric spinel, a low-pressure analogue for nominally anhydrous minerals in Earth’s mantle. Data are fitted to the following Arrhenius law: Diffusivity (m2/s)?=?4?±?1?×?10?12 exp(?54?±?2 kJ?mol?1/RT). At low temperatures, H+ and D+ diffusion in non-stoichiometric spinel is charge balanced by flux of O vacancies, with infrared data consistent with protonation of both octahedral and tetrahedral O–O edges in non-stoichiometric spinel, and additional fine structure due to Mg–Al mixing and/or coupling of structurally incorporated H+ with cation vacancies. Absence of changes in the fine structure of O–H absorption bands indicates that H+ can become locally coupled and uncoupled to other defects during bulk diffusion. As such, proton conductivity in spinel group minerals, arising from faster flux of uncoupled H+, can only be calculated from H+ mobility data if the extent of defect coupling is constrained. 相似文献
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In this study, scallop mantle protein was treated by ultrasound at different powers, and then analyzed by ANS fluorescent probes, circular dichroism spectroscopy, endogenous fluorescence spectrum, DNTB colorimetry and in-vitro digestion model to elucidate the structure–function relationship. The results indicated that ultrasound can significantly affect the secondary structure of scallop mantle protein like enhancing hydrophobicity, lowering the particle size, increasing the relative contents of α-helix and decreasing contents of β-pleated sheet, β-turn and random coil, as well as altering intrinsic fluorescence intensity with blue shift of maximum fluorescence peak. But ultrasound had no effect on its primary structure. Moreover, the functions of scallop mantle protein were regulated by modifying its structures by ultrasound. Specifically, the protein had the highest performance in foaming property and in-vitro digestibility under ultrasonic power of 100 W, oil binding capacity under 100 W, water binding capacity under 300 W, solubility and emulsification capacity under 400 W, and emulsion stability under 600 W. These results prove ultrasonic treatment has the potential to effectively improve functional properties and quality of scallop mantle protein, benefiting in comprehensive utilization of scallop mantles. 相似文献
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Abstract We have determined the solidus for mantle peridotite with excess water. The solidus is important for prediction of temperature and depth of melting. Our results give slightly higher temperatures than predicted by extrapolation from lower pressure piston cylinder data. Melting may be restricted to shallower depths than previously expected. 相似文献
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新生代玄武岩及其幔源包体是研究地球深部上地幔物质组成和成因的探针。对发现于浙江省东南沿海玉环县石峰山地区的橄榄玄武岩及其所含的大量二辉橄榄岩包体与单斜辉石捕虏晶进行了研究。结果表明,橄榄玄武岩中这些幔源包体主要为尖晶石相,橄榄石和辉石的Mg#分别在90%和90%~91%,对应为镁橄榄石和顽火辉石端元,尖晶石Cr#[Cr/(Cr+Al)]在0.1左右,为富铝尖晶石,与福建明溪、浙江新昌等地玄武岩中幔源包体的矿物成分相近,指示其地幔源区部分熔融程度不高。另外,单斜辉石捕虏晶呈浑圆状,其被捕获上涌过程中与岩浆发生了少量物质交换。镜下观察与电子探针背散射图像(BSE)显示,二辉橄榄岩与捕虏晶中的单斜辉石均发育有“筛状结构”,指示了明显的长英质熔体熔出现象。这种现象可以解释为早期K、Na含量较高的单斜辉石在岩浆上涌过程中发生减压,导致富含K、Na成分的熔体析出,随后经快速冷却形成,而非外来熔体交代形成。 相似文献
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Tomoyuki Kobayashi Junji Yamamoto Takao Hirajima Hidemi Ishibashi Naoto Hirano Yong Lai Vladimir S. Prikhod'ko Shoji Arai 《Journal of Raman spectroscopy : JRS》2012,43(8):1126-1133
To assess the ability of densimetry for CO2 fluid in CO2 inclusions, we compare two methods, microthermometry and Raman microspectroscopic densimetry for CO2. The comparative experiment was performed for nine CO2 inclusions in three mantle xenoliths. The results are as follows: (1) microthermometry precisely determines CO2 density with the range of 0.65 to 1.18 g/cm3 compared with Raman microspectroscopic densimetry; (2) CO2 density obtained by Raman microspectroscopic densimetry is fairly consistent with that by microthermometry; (3) it is hard to determine CO2 density in CO2 inclusion with diameter of less than around 3 µm using microthermometry; and (4) microthermometry can be applied only to the CO2 inclusion whose CO2 density ranges from around 0.65 to 1.18 g/cm3, whereas the Raman microspectroscopic densimetry is applicable to CO2 density ranging from 0.1 to 1.24 g/cm3. The above features carry the potential for estimation of depth origin of mantle‐derived rocks. The depth where the rocks were trapped by host magma can be estimated using both geothermometric data and CO2 fluid density in CO2 inclusions in the rocks. Typical precisions of density of CO2 in CO2 inclusions obtained by the Raman microspectroscopic densimetry (~0.01 g/cm3) and by the microthermometry (< 0.001 g/cm3) correspond to uncertainties in the depth origin of 2.4 km and < 1.7 km, respectively, at 1000 ± 50 °C. In case of the mantle under 750–1250 °C and 1 GPa, the CO2 fluid has a density ranging from 1.06 g/cm3 to 1.21 g/cm3, which are well measured by the Raman microspectroscopic densimetry. Combination of both densimetries for CO2 in mantle minerals elucidates the deep structure of the Earth. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献