Due to various courses of formation of zircons from kimbedites, different kinds of zircons can provide useful information about the mantle and the crystallization of kimberlites. We chose 9 typical ones out of 33 zirc...Due to various courses of formation of zircons from kimbedites, different kinds of zircons can provide useful information about the mantle and the crystallization of kimberlites. We chose 9 typical ones out of 33 zircons from the Shengli- 1 kimberlite pipe in Mengyin County, Shandong Province to study their ages and formation by means of SHRIMP, CL, Raman spectroscopy, etc. The result shows that the ^207Pb/^206Pb ages of many zircons vary from 2567±13 Ma to 2636±42 Ma, which are close to the age of Archaean granitoid （2457.3±47 Ma） in the study area. The contents of U and Th in the samples are higher than those of zircons crystallized in kimbedite and vary from 89 to 398 ppm as well as from 10 to 283 ppm. Color zones are obvious in these samples under the CL. The inclusions are composed of feldspar, quartz, apatite, etc. The above results show that the zircon samples came from the crust of the earth, which means that the kimberlite magmas are contaminated by crustal substances. The position where a great deal of volatile escapes and even explodes during rapid rise of magmas is located at the boundary of the ancient basement and the Precambrian stratum.展开更多
Some geochemical characters of the kimberlites from different rock regions in North China platform are compared in this paper at first. The characters of the source regions are constrained then based on primary magmas...Some geochemical characters of the kimberlites from different rock regions in North China platform are compared in this paper at first. The characters of the source regions are constrained then based on primary magmas compositions of typical regions chosen. The differences in metasomatic fluid activity in the lithosphere are discussed moreover. The diamondiferious kimberlitic sources, such as Fuxian and Mongying, were located at the fluid metasomatic mantle lithosphere or the boundary between the lithosphere and the asthenosphere(200-230 km), and enrich in LREE,Ti and isotope Sr but deplete in isotope Nd. Tieling is located nearby Paleozoic mobile belt, strong activity in fluids and shallower depth of magma source (～150 km), highest in w(LREE) and w (P), lower in w(Ti). But the shallowest depth of magma source (<130 km ) and weak activity in fluids are in Hebi and Shexian sources.展开更多
学习大学英语课程是医学院校学生提高英语素养的主要途径,其课程设置既需要满足培养医科学生基本英语技能和跨文化交际能力在内的人际交流基本技能需求,还需要满足培养医学生医学专业学术语言能力的需求。本文阐述首都医科大学根据医学...学习大学英语课程是医学院校学生提高英语素养的主要途径,其课程设置既需要满足培养医科学生基本英语技能和跨文化交际能力在内的人际交流基本技能需求,还需要满足培养医学生医学专业学术语言能力的需求。本文阐述首都医科大学根据医学院校专业人才培养目标、依据ESP教学理论,开展大学英语课程设置的教改实践过程,指出医学院校大学英语课程应在医学人才培养过程中发挥积极作用,课程设置可由通用英语课程、桥梁阶段课程和专业英语课程共两个阶段三个层次的课程群组成,统称'医学英语'(EMP,即English for Medical Purposes)。首都医科大学大学英语课程改革实践中的问题解决途径可为其他医学院校提供参考。展开更多
Based on the LAM-ICPMS analytic results on the trace elements of clinopyroxenes in peridotitic xenoliths occurring in early-Cretaceous basalts from western Xinjiang, the properties and the deep processes, including pa...Based on the LAM-ICPMS analytic results on the trace elements of clinopyroxenes in peridotitic xenoliths occurring in early-Cretaceous basalts from western Xinjiang, the properties and the deep processes, including partial melting and mantle metasomatism, of the subcontinental lithospheric mantle beneath the Tuoyun Basin are analyzed. In the northern edge of the Tarim Basin (southwest Tian-shan), the Mesozoic subcontinental lithosphere which has experienced the effect of partial melting (【10%) and intricate mantle metasomatism is characterized by Phanerozoic ’ocean-type’ mantle. The superposed influence of SiO2-un-saturated silicate melt and carbonate melt probably results in the metasomatic medium which resembles the hydrous silicated carbonate melt in some aspects. By comparing Tuoyun mantle with Cenozoic main mantle beneath eastern China, the properties are similar, while the former shows finer grain and higher diopside content of the peridotites and more conspicuous modal metasomatism.展开更多
A few texturally-zoned garnets were found in a polymict peridotite (JJG1414) from the Cretaceous kimberlite, Kimberley South Africa. The systematic analyses of electron and ion microprobe as well as laser fluorination...A few texturally-zoned garnets were found in a polymict peridotite (JJG1414) from the Cretaceous kimberlite, Kimberley South Africa. The systematic analyses of electron and ion microprobe as well as laser fluorination technique reveal the existencal of marked elemental and oxygen isotopic zonation in these gamed. corresponding to the textural zonation. The rims are normally enriched in Ca, Ti, Cr, LREE. Sr, Nb, and depleted in Mg, Al and 18O. It is demonstrated that these gamats were infiltrated by melts/fiuids, probably representing the disequilibrated products of fluid-asssted mantle deformation.展开更多
The CL images show that the internal structures of the diamonds in Wafangdian, Liaoning Province is classified as three types: simple growth girdle zone, multi-stage growth complex girdle zone, and rare agate-like str...The CL images show that the internal structures of the diamonds in Wafangdian, Liaoning Province is classified as three types: simple growth girdle zone, multi-stage growth complex girdle zone, and rare agate-like structure. These internal features reflect the complexity of growth processes of the diamonds. The FTIR analyses in micro area on diamond plates reveal the heterogeneity of the impurities of nitrogen and hydrogen. The variety of nitrogen contents and nitrogen aggregation states have been revealed not only in different diamonds from one kimberlite pipe but also in different zones of one diamond. The extent of conversion A defects to the aggregated B form is a function of the nitrogen aggregation temperature (TNA), mantle residence time (tMR), and nitrogen concentration of diamond. The interval of 0.6-0.7Ga from core to rim of diamond growth is obtained by using the FTIR curves and some geological data. The long period of diamond growth is identical with the feature in CL image.展开更多
基金supported by the National Natural Science Foundation of China(40272021)the Outstanding Young Teachers Project of China University of Geosciences(CUGQNL0319).
文摘Due to various courses of formation of zircons from kimbedites, different kinds of zircons can provide useful information about the mantle and the crystallization of kimberlites. We chose 9 typical ones out of 33 zircons from the Shengli- 1 kimberlite pipe in Mengyin County, Shandong Province to study their ages and formation by means of SHRIMP, CL, Raman spectroscopy, etc. The result shows that the ^207Pb/^206Pb ages of many zircons vary from 2567±13 Ma to 2636±42 Ma, which are close to the age of Archaean granitoid （2457.3±47 Ma） in the study area. The contents of U and Th in the samples are higher than those of zircons crystallized in kimbedite and vary from 89 to 398 ppm as well as from 10 to 283 ppm. Color zones are obvious in these samples under the CL. The inclusions are composed of feldspar, quartz, apatite, etc. The above results show that the zircon samples came from the crust of the earth, which means that the kimberlite magmas are contaminated by crustal substances. The position where a great deal of volatile escapes and even explodes during rapid rise of magmas is located at the boundary of the ancient basement and the Precambrian stratum.
文摘Some geochemical characters of the kimberlites from different rock regions in North China platform are compared in this paper at first. The characters of the source regions are constrained then based on primary magmas compositions of typical regions chosen. The differences in metasomatic fluid activity in the lithosphere are discussed moreover. The diamondiferious kimberlitic sources, such as Fuxian and Mongying, were located at the fluid metasomatic mantle lithosphere or the boundary between the lithosphere and the asthenosphere(200-230 km), and enrich in LREE,Ti and isotope Sr but deplete in isotope Nd. Tieling is located nearby Paleozoic mobile belt, strong activity in fluids and shallower depth of magma source (～150 km), highest in w(LREE) and w (P), lower in w(Ti). But the shallowest depth of magma source (<130 km ) and weak activity in fluids are in Hebi and Shexian sources.
文摘学习大学英语课程是医学院校学生提高英语素养的主要途径,其课程设置既需要满足培养医科学生基本英语技能和跨文化交际能力在内的人际交流基本技能需求,还需要满足培养医学生医学专业学术语言能力的需求。本文阐述首都医科大学根据医学院校专业人才培养目标、依据ESP教学理论,开展大学英语课程设置的教改实践过程,指出医学院校大学英语课程应在医学人才培养过程中发挥积极作用,课程设置可由通用英语课程、桥梁阶段课程和专业英语课程共两个阶段三个层次的课程群组成,统称'医学英语'(EMP,即English for Medical Purposes)。首都医科大学大学英语课程改革实践中的问题解决途径可为其他医学院校提供参考。
基金This work was supported by the National Natural Science Foundation of China (Grant Nos. 40072021 and 49733110) and the State Key Basic Research Development Program (Grant No. G1999043303).
文摘Based on the LAM-ICPMS analytic results on the trace elements of clinopyroxenes in peridotitic xenoliths occurring in early-Cretaceous basalts from western Xinjiang, the properties and the deep processes, including partial melting and mantle metasomatism, of the subcontinental lithospheric mantle beneath the Tuoyun Basin are analyzed. In the northern edge of the Tarim Basin (southwest Tian-shan), the Mesozoic subcontinental lithosphere which has experienced the effect of partial melting (【10%) and intricate mantle metasomatism is characterized by Phanerozoic ’ocean-type’ mantle. The superposed influence of SiO2-un-saturated silicate melt and carbonate melt probably results in the metasomatic medium which resembles the hydrous silicated carbonate melt in some aspects. By comparing Tuoyun mantle with Cenozoic main mantle beneath eastern China, the properties are similar, while the former shows finer grain and higher diopside content of the peridotites and more conspicuous modal metasomatism.
文摘A few texturally-zoned garnets were found in a polymict peridotite (JJG1414) from the Cretaceous kimberlite, Kimberley South Africa. The systematic analyses of electron and ion microprobe as well as laser fluorination technique reveal the existencal of marked elemental and oxygen isotopic zonation in these gamed. corresponding to the textural zonation. The rims are normally enriched in Ca, Ti, Cr, LREE. Sr, Nb, and depleted in Mg, Al and 18O. It is demonstrated that these gamats were infiltrated by melts/fiuids, probably representing the disequilibrated products of fluid-asssted mantle deformation.
文摘The CL images show that the internal structures of the diamonds in Wafangdian, Liaoning Province is classified as three types: simple growth girdle zone, multi-stage growth complex girdle zone, and rare agate-like structure. These internal features reflect the complexity of growth processes of the diamonds. The FTIR analyses in micro area on diamond plates reveal the heterogeneity of the impurities of nitrogen and hydrogen. The variety of nitrogen contents and nitrogen aggregation states have been revealed not only in different diamonds from one kimberlite pipe but also in different zones of one diamond. The extent of conversion A defects to the aggregated B form is a function of the nitrogen aggregation temperature (TNA), mantle residence time (tMR), and nitrogen concentration of diamond. The interval of 0.6-0.7Ga from core to rim of diamond growth is obtained by using the FTIR curves and some geological data. The long period of diamond growth is identical with the feature in CL image.
