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We first report discovery of the spinel-garnet-orthopyroxene granulite with pure CO2 fluid inclusions from the Fuyun region of the late Paleozoic Altay orogenic belt in Central Asia, NW China. The rock is characterized by an assemblage of garnet, orthopyroxene, spinel, cordierite, biotite, plagioclase and quartz. Symplectites of orthopyroxene and spinel, and orthopyroxene and cordierite indicate decompression under UHT conditions. Mineral chemistry shows that the or-thopyroxenes have high XMg and A12O3 contents (up to 9.23 wt%). Biotites are enriched in TiO2 and XMg and are stable under granulite facies conditions. The garnet and quartz from the rock carry monophase fluid inclusions which show peak melting temperatures of around -56.7℃, indicating a pure CO2 species being presented during the ultrahigh-T metamorphism in the Altay orogenic belt. The inclusions homogenize into a liquid phase at temperatures around 15.3-23.8℃ translating into CO2 densities of the order of 0.86-0.88 g/cm3. Based on prelim 相似文献
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INTRODUCTION Due to granulites representing products of thedeeper lower crust-upper mantle and having geneticassociation with early crustal evolution and forma-tion of large-scale metallogenic-forming and nonmetallogenic-forming belts, the study of granulitesin the world has resulted in much recent attention(Zhai and Liu, 2001; Liu and Zhou, 1994; Yu et al.,1998; 2003; Li et al., 2000; Zhang et al., 2001; Yuet al., 2002; Bingen and Stein, 2003; Blein et al.,2003; Garcia et al., … 相似文献
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We first report discovery of the spinel-garnet-orthopyroxene granulite with pure CO2 fluid inclusions from the Fuyun region of the late Paleozoic Altay orogenic belt in Central Asia, NW China. The rock is characterized by an assemblage of garnet, orthopyroxene, spinel, cordierite, biotite, plagioclase and quartz. Symplectites of orthopyroxene and spinel,and orthopyroxene and cordierite indicate decompression under UHT conditions. Mineral chemistry shows that the orthopyroxenes have high XMg and Al2O3 contents (up to 9.23 wt%). Biotites are enriched in TiO2 and XMg and are stable under granulite facies conditions. The garnet and quartz from the rock carry monophase fluid inclusions which show peak melting temperatures of around -56.7 ℃, indicating a pure CO2 species being presented during the ultrahigh-T metamorphism in the Altay orogenic belt. The inclusions homogenize into a liquid phase at temperatures around 15.3-23.8℃ translating into CO2densities of the order of 0.86-0.88 g/cm3. Based on preliminary mineral paragenesis, reaction textures and petrogenetic grid considerations, we infer that the rock was subjected to UHT conditions. The CO2-rich fluids were trapped during exhumation along a clockwise P-T path following isothermal decompression under UHT conditions. 相似文献
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在追及、碰撞问题中,当两个物体速度相同(即相对速度为零)时,通常伴随着某些物理特征出现.如果我们在解题时,能弄清楚并加以区别"速度相同"时系统出现的不同特征,各种追、撞总是便很易求解.下面结合具体范例作分类分析. 相似文献
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本文分析了国际研究生教育的发展趋势和时代特征,研究了我国研究型大学发展研究生教育所取得的成效及存在的不足和问题,提出我国研究型大学应从国际竞争环境和现实社会需求出发,先行一步将研究生教育的重点从注重规模的扩张转移到注重结构的调整,注重质量和效益的提高上来,并提出了我国研究型大学研究生教育发展的目标、思路和策略。 相似文献
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The basic granulite of the Altay orogenic belt occurs as tectonic lens in the Devonian medium- to lower-grade metamorphic beds through fault contact. The Altay granulite (AG) is an amphibole plagioclase two-pyroxene granulite and is mainly composed of two pyroxenes, plagioclase, amphibole and biotite. Its melano-minerals are rich in Mg/(Mg Fe2 ),and its amphibole and biotite are rich in TiO2. The AG is rich in Mg/(Mg Fe2 ), Al2O3 and depletion of U, Th and Rb contents. The AG has moderate ∑REE and LREE-enriched with weak positive Eu anomaly. The AG shows island-arc pattern with negative Nb, P and Ti anomalies, reflecting that formation of the AG -05 be associated with subduction. Geochemical and mineral composition data reflect that the protolith of the AG is calc-alkaline basalt and formed by granulite facies metamorphism having peak P-T conditions of 750 ℃-780 ℃ and 0.6-0.7 Gpa. The AG formation underwent two stages was suggested. In the early stage of oceanic crustal subduction, calc-alkaline basalt with island-arc environment underwent granulite facies metamorphism to form the AG in deep crust, and in the late stage, the AG was thrust into the upper crust. 相似文献
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在分析目前研究生教育质量评估模型的基础上,构建了基于培养过程的研究生教育质量评估理论模型,并根据模型阐述了研究生教育质量管理体系,以进一步提高研究生教育质量。 相似文献
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谈博士生学术格局的构建 总被引：1，自引：0，他引：1
杨树锋 《学位与研究生教育》2003,(12):6-7
1978年,我国恢复硕士研究生招生,我考入南京大学地质学系构造地质学专业,师从著名地质学家郭令智院士;1982年初,我在郭老师指导下继续博士研究生学业,1984年底,我的博士学位论文通过答辩,我有幸成为我国实施学位制度以来自己培养的第一位地质学博士。在学期间,我还担任了研究生支部书记、研究生辅导员。1985年我留南京大学任教后即开始招收硕士生,并协助指导博士生,担任地质学系副主任和校学位评定委员会系分委员会副 相似文献