Discovery of super-silicic and super-titanic garnets in garnet-pyroxenite in Zhaheba and its geological significance

Super-silicic garnet which exists stably at more than 5 GPa is a typical ultra-high pressure mineral. The super-silicic garnet and super-titanic garnet were discovered for the first time in garnet-pyroxenlte of early Paleozoic Zhaheba-Aermantai orogenic belt in north Xinjiang. Our study indicates that these su per-silicic garnets as well as super-Utanic garnets were formed at a depth of at least 300 km. Their host rock-garnet-pyroxenite is one kind of ultra-pressure metamorphic rocks which is related to the ultra-deep subduction of the oceanic crust. Thus, the early Paleozoic Zhaheba-Aermantai orogenic belt is related to the ultra-deep aubduction of the Paleo-Aaian oceanic crust.     

大别山超高压榴辉岩中的结构水及其氢点缺陷的研究

对大别山榴辉岩中的"名义上无水矿物"(NAMs)石榴石、绿辉石、金红石的傅立叶变换红外光谱(FTIR)观察表明,它们都含有以OH-或者H2O形式存在的氢,结构水含量分别为410-1391ppm,511-1638ppm,728-2158ppm,同时结合地球物理化学等因素对NAMs中与氢相关的点缺陷性质进行了初步探讨.     

Discovery of eclogite at northern margin of Qaidam Basin, NW China

Eclogite was first discovered at the northern margin of the Qaidam Basin in this study. It occurs as pods in the gneiss sequence of Middle to Upper Proterozoic age and is mainly composed of garnet, omphacite, phengite and rutile. The garnets contain 44%-62% of almandine, 15%-33% of grossular and 12%-30% of pyrope molecules, and the omphacites contain 40%-46% of jadeite. Applying garnet_clinopyroxene thermometry and jadeite geobarometry, the peak conditions of eclogite facies metamorphism occurred at about (722±123)℃ and at the pressure of up to c. 22 ×10 8 Pa.     

中国滑坡崩塌危险性区划

中国滑坡、崩塌灾害日趋严重,对这两种突发性泥沙灾害进行危险性区划具有重要意义.根据滑坡崩塌发生机理选择危险度的基本指标,建立了基于县市行政区的形成条件数据库和重大灾害数据库.采用突发性泥沙灾害危险性快速区划方法将中国分为高危险度区、较高危险度区、中危险度区、较低危险度区和低危险度区.通过图形的叠加计算,对区划结果与形成条件分布的相关性进行分析.同时采用重大历史灾害分布统计,直接验证了快速区划方法的可靠性.     

不确定性推理及其在斜坡类地质灾害危险性区划中的应用

通过对不确定性推理方法尤其是概率推理方法的研究,将其引入到斜坡类地质灾害危险性区划之中。在对不确定因子法、主观贝叶斯法、贝叶斯网络法和影响图法等4种不确定性推理方法进行原理分析的基础上,分别给出了其在斜坡类地质灾害危险性区划中的应用思路,并在辽宁省鞍山市岫岩县进行了试验,进而总结形成了一套基于不确定性推理开展斜坡类地质灾害危险性区划的方法体系,实现了对传统区划方法的改进。     

西藏地区盐湖锂的地球化学分布规律

通过统计西藏高原盐湖镁离子及锂离子质量浓度的水化学数据和镁锂离子质量浓度比值,绘制出西藏地区盐湖卤水锂离子质量浓度分布等值线图和镁锂离子质量浓度比值分布图,分析了西藏地区盐湖锂资源品位及品质在空间上的分布规律以及盐湖锂资源富集与其所处地质环境的关系。分析表明:西藏地区盐湖锂资源的分布呈现分带性特征,盐湖锂离子质量浓度可能受构造带的控制,碳酸盐型盐湖带的盐湖卤水镁锂离子质量浓度比值最低,高品质低镁锂比卤水盐湖和低镁锂比卤水盐湖集中分布在碳酸盐型盐湖带-硫酸盐型盐湖带过渡区内。     

陕西省地质灾害风险区划初步研究

省域地质灾害风险区划研究与实践处于起步阶段。在借鉴自然灾害风险的基础上,提出了省域地质灾害风险区划研究思路方法。在地质灾害危险性评价与区划和地质灾害经济社会易损性区划的基础上,采用GIS平台,进行了陕西省地质灾害风险区划初步研究,得到了陕西省地质灾害风险区划初步结果。研究表明:陕西省地质灾害风险区可以划分为高、中、低和极低4级风险区,其中高中风险区15个,面积约占陕西国土面积的35%。这些风险区应成为今后地质灾害防治的重点。     

Heterogeneity of water in UHP eclogites from Bixiling in Dabieshan： Evidence fromgarnet

Garnets in ultrahigh pressure (UHP) eclogites from Bixiling in Dabieshan were investigated by Fourier transform infrared spectrometer (FTIR). The results demonstrate that all garnets contain structural water which occurs as hydroxyl (OH), with contents ranging from 164 to 2034 ppm (H2O wt.) and mostly higher than 500 ppm. Like omphacite which is another major OH-rich mineral in eclogites, garnet is an important carrier that can recycle the surface water into deep mantles. Heterogeneity of water in garnets exists not only among different samples of the same outcrop (～150 m), but also among different crystals of the same sample (～1 cm). This indicates that the mobility of fluids during UHP metamorphism is very limited (possibly on centimeter scales), and that both subduction and exhumation processes of UHP rocks are very fast.     

中国典型季风区分子化石记录的生物空间分异

目的揭示中国典型季风区分子化石记录的生物分布的空间分异。方法利用GC-MS对典型季风区泥炭剖面进行分子化石的检测和分析。结果全新世时期,不同季风气候带的正构烷烃分布特征明显不同,从南到北依次为nC29—nC31(少量为nC25)—nC27,nC29,nC31为优势,说明不同地带同一时期植被输入呈明显的分异特征。结论中国全新世不同空间格局的生物,从南到北具有明显的空间分异特点,是生物-气候共同作用的结果。     

NPP distribution related to the terrains along the North-South Transect of Eastern China

Vegetation net primary productivity (NPP) is defined as the accumulative amount of organic matters per unit area and time, which is calculated from the difference between accumulative photosynthesis and accumulative autotrophic respiration by green plants. Since the NPP reflects the physiological and ecological characteristics of the plants and the interactive results of the environmental factors, it is an important index to evaluate a structure of ecological system, functional features and …     

Sm-Nd age dating of high-pressure granulites and amphibolite from Sanggan area, North China craton

The high pressure (HP) metamorphic age has been dated to HP rocks from the Sanggan area, North China craton. We have got garnet+whole rock isochron ages of (1 842±38) Ma for HP granulite, and (1 856 ± 26) Ma for HP amphibolite. The Sm-Nd whole rock isochron of HP granulites give out an age of (1 870±150) Ma with Nd depleted mantle model age of (2 402—2 482) Ma. Considering the Nd isotope homogenization during the peak metamorphism of the HP granulite, Sm-Nd closure temperature and the retention of Nd isotopic memory in garnets partially broken down during decompression, all these isochron ages are thought to be HP metamorphic age. Furthermore, we proposed that the HP metamorphism took place at the end of Paleoproterozoic during the large-scale collision and assembly of the North China craton.     

松辽盆地有效热储层的识别与划分技术

给出了有效热储层的定义。建立了利用测井资料进行有效热储层定性和定量识别与划分方法,并依据松辽盆地有效热储层分布情况,建立了有效热储识别下限标准。应用计算机技术对松辽盆地进行了有效热储层的识别与划分,经研究实践表明有效热储层识别原理和方法是正确的、是可行的,为进一步研究地热储特征提供了重要依据。     

松辽盆地有效热储层识别与划分技术

本文给出了有效热储层的定义,建立了利用测井资料进行有效热储层定性和定量识别与划分方法,并依据松辽盆地有效热储层分布情况,建立了有效热储识别下限标准,应用计算机技术对松辽盆地进行了有效热储层的识别与划分,经研究实践表明有效热储层识别原理和方法是正确的、是可行的,为进一步研究地热储特征提供了重要依据。     

青海哈西亚图多金属矿床地质特征及成因探讨

为了加快青海省优势环境与战略矿产勘查进程,文中对哈西亚图多金属矿床成矿地质背景、矿床地质特征、控矿因素及成因进行了综合分析,研究结果表明:哈西亚图多金属矿床已发现矿体的成因类型为矽卡岩型,矿体从垂向上看,可分为4层均产于具垂直分带的矽卡岩带中,受矽卡岩类型影响矿石类型在垂向上也具有明显分带性,在华力西期花岗闪长岩与古元古界金水口岩群的碳酸盐岩的接触带附近为主要成矿部位,通过早期区域变质作用、矽卡岩化作用及晚期的热液成矿作用3个阶段,形成了以磁铁矿体为主,铜、铅、锌、金并存的多金属矿床。     

Earthquake Resistant Engineering and Application of Seismic Zonation Map of ChinaTechnicalInnovations

1Introduction　Chinaisacountrywithhighearthquakedisaster.Thego vernmentalwayskeepsaneyeonseismicresistantbuilding.Thepublishedseismiczonationmapprovidestheruleforcon structionseismicresistantfortification .Fortheconvenientuse ,theseismicresistantfortificationruleofseismiczonationmapandbasiccontentandmeaningisbrieflyintroduced .Forthosekeyprojectsofsuperhighorsuperlongconstruction ,forexample ,largedam ,nuclearpowerplant,largepetrochemi calplantetc .,duetohighinvestmentandhighsocietyinf luence…     

非胎生红树植物繁殖体特征与分带关系

利用分带值的方法调查了海南东寨港和清澜港的红树林群落结构组成状况,比较了4种非胎生红树植物(瓶花木、海漆、榄李和老鼠簕)的繁殖体散布特征(大小、质量和漂浮性)和萌发的初始时间和萌发率的情况.4种非胎生红树植物在潮间带的位置从海到陆依次是:瓶花木、海漆、榄李和老鼠簕.繁殖体的大小按长度依次是榄李>老鼠簕>瓶花木>海漆,按质量依次是老鼠簕>榄李>瓶花木>海漆.瓶花木和榄李有很好的漂浮性,其次是海漆,老鼠簕的漂浮性最差.榄李的种子具有休眠的特点,因此萌发实验用50 d湿处理对榄李进行解除休眠.盐度高于30时榄李不能萌发,而老鼠簕对盐度具有很好的耐受性,在30盐度以下,萌发率都很高,甚至达到了100%.4种非胎生红树植物繁殖体的散布特征和萌发情况,对于了解红树植物在潮间带的分带现象有重要意义.     

Northern Tibetan Plateau cooling and aridification linked to Cenozoic global cooling: Evidence from <Emphasis Type="Italic">n</Emphasis>-alkane distributions of Paleogene sedimentary sequences in the Xining Basin

The Xining Basin on the northeastern Tibetan Plateau holds the longest continuous Cenozoic stratigraphic record in China. The sequence record contains considerable information on the history of Tibetan uplift and associated climatic change. In particular, high resolution n-alkane biomarker proxy and pollen records have been obtained from the Paleogene sediments of the Xiejia section of the basin. A combination of the n-alkane and palynological records reveals that the paleoclimate in the Xining Basin experienced a long-term cooling trend from 50.2 to 28.2 Ma with a distinctive ecological event spanning 37.5 to 32.7 Ma. Since this ecological event, a vertical zonation of vegetation from lowland arid grasses, to middle-elevation subtropical broad-leaf plants, to high-elevation coniferous trees was established. We interpret that these changes in climate and vegetation were probably responses to a combination of long term global cooling since the Eocene climatic optimum and uplift of the surrounding mountains on the northern Tibetan Plateau in the early Cenozoic.     

An experimental study of phase transformations in olivine under pressure and temperature conditions corresponding to the mantle transition zone

High-pressure polymorphs of olivine (wadsleyite and ringwoodite) are major minerals in the mantle transition zone (MTZ).Phase transformations in olivine are important for a series of geodynamic problems such as the mineralogical and evolutionary history of the mantle,mantle convection patterns,and deep focus earthquakes in subduction zones.In this study,we examine phase transformations in olivine with two compositions,namely Mg 2 SiO 4 (Fo 100) and (Mg 0.9 Fe 0.1) 2 SiO 4 (Fo 90),at pressures between 14.1 and 20 GPa and a constant temperature of 1400°C,using the newly installed multi-anvil system at the Laboratory for Studies of the Earth’s Deep Interior (SEDI),China University of Geosciences (Wuhan).At 14.1 GPa,Fo 90 transformed completely into the wadsleyite structure (β),while Fo 100 remained as olivine (α).Between 14.8 and 15.6 GPa,both Fo 100 and Fo 90 transformed into the wadsleyite structure.Wadsleyite crystals were identified by two characteristic Raman peaks between 722 and 723 and 917 and 919 cm 1.They exhibit a bimodal grain size distribution:large-crystals with average grain sizes greater than 100 μm and microcrystals less than 10 μm.The population of microcrystals increased with pressure,apparently due to the increase in over-pressure (the difference between the experimental pressure condition and the equilibrium transformation pressure at 1400°C),which promotes nucleation and retards grain growth.All run charges contained large numbers of wadsleyite microcrystals,because of the low activation energy of the nucleation process.The experimentally observed microstructure may shed light on the morphology of wadsleyite observed in shocked meteorites.At 19.5 GPa,wadsleyite coexisted with ringwoodite (γ) in Fo 100,but was absent in Fo 90.At 20 GPa,both samples transformed completely into ringwoodite,which was characterized by the 798 and 840 cm 1 Raman lines.Ringwoodite crystals are euhedral grains (average grain size 10-20 μm),with well-developed triple junctions.The complex upper mantle structure in eastern China determined from seismological studies cannot be explained by the simple transformation sequence of the olivine system alone.Phase transformations in other pyroxene-normative components (including pyroxenes and garnets) and the interaction of these components with olivine may be responsible for the complex structure.High-pressure and high-temperature experimental studies on complex systems (e.g.olivine-pyroxene),combined with data from geophysical exploration,may help in establishing a more realistic geological-petrological model for eastern China and further our understanding of the possible physical mechanisms that are responsible for the complex structure.Such studies will have profound implications for understanding the dynamic processes in the deep Earth interior.     

基于GIS的辽宁省岫岩县泥石流灾害危险性区划研究

利用GIS技术,以辽宁省鞍山市岫岩满族自治县为例,针对泥石流灾害研究过程中的不确定性,应用确定因子法对泥石流灾害危险性区划进行研究。基于岫岩县地质灾害调查资料,借助GIS的数字化、空间分析等功能,获得泥石流灾害点分布图及其影响因子图,进而利用叠置分析获得按均一条件单元划分的研究区图。根据确定因子法计算每一数据类对应的CF值,然后采用逻辑回归模型进行分析,建立岫岩县泥石流危险性评价模型,利用该模型进行危险性分析,得到岫岩县泥石流危险性区划图。经过灾害点数据的效果检验,证明本方法能够较好地反映泥石流灾害区域危险性特征。     

植物区系特征成分及地带性分化问题的探讨

简述关于植物区系成分以及中国植物区系的研究进展,讨论细胞学、分子生物学等新技术在开展特征植物区系成分地带性分化以及分子生物地理学研究方面的意义。