大别山超高压变质岩组合中石榴硬玉石英岩及相关岩石的特征——陆壳成因岩石的证据

查明超高压变质岩系的原岩、原岩建造,是认识变质前历史、探讨超高压变质作用地球动力学机制和陆壳再循环的重要环节。近来的研究表明,大别山造山带中出露的超高压变质岩系的原岩,主要为基性火山岩、碳酸盐岩、碎屑岩等陆壳岩石。安徽省岳西县境内超高压变质岩分布较广,其中碧溪岭地区发育了大别山造山带中出露面积最大的以榴辉岩为主的超高压变质岩组合(图1)。大多数研究者认为碧溪岭超高压变质岩组合的原岩属镁铁质—超镁铁质侵入岩,因而称为碧溪岭岩体(张旗1993,刘若     

海南岛西部青白口系石碌群褶皱变形特征及其控矿分析

青白口系石碌群属于一套海相沉积经变质的以细粒碎屑岩、泥岩及镁质碳酸岩夹火山岩为原岩的变质岩系组合,赋存有沉积变质型铁矿和热液型铜钴矿。岩石经历了多期次变形作用的改造,总体表现为由褶皱变形往韧脆性断裂变形演化的特征,褶皱变形包含了三个变形序列的构造形迹组合。与铁矿主成矿期密切有关的NW向石碌复向斜属于海西．印支期造山运动...     

山西省大同市新荣区石墨矿岩石矿物地球化学特征与成因

山西省大同市新荣区石墨矿带总体呈北东—南西向展布, 长约22 km, 赋矿层位为中下太古界右所堡组, 岩性为含石墨黑云斜长片麻岩。目前该矿带上已有7个勘查区, 累计查明晶质石墨矿物资源量约 5000万吨, 但对其矿床成因类型研究相对较少。本文收集整理和分析总结了区域内地质资料及化验分析结果, 采用变质岩原岩恢复的四种方法确定该矿带的成因: 从石墨矿带的矿体产状和岩石组合、岩相学和矿物学特征定性判断该矿带矿床为沉积岩区域深变质成矿类型; 矿体样品地球化学微量元素比值(Sr:Ba等)符合副变质岩特征; 稀土元素配分曲线及其研究表明矿体及围岩具有沉积岩变质特征; 以TiO2-F图解、[(al+fm)–(c+alk)]/Si图解以及(al-alk):c图解展示的岩石化学特征半定量地确认新荣区石墨矿带矿床为以黏土岩为主的区域变质成矿。新荣区石墨矿带成因类型的确定填补了该区域矿床成因类型研究的空白, 为下一步地质找矿及建模提供了重要依据; 三种图解相结合, 逐步缩小原岩范围, 锁定原岩类型, 为变质岩原岩恢复及矿床成因研究提供了新的思路和判别方法。     

湖北省宜昌市彭家河石榴石矿床地质特征及成因分析

运用矿物学、岩石学的方法对宜昌黄陵地区彭家河石榴石矿床中含矿层的矿物组合、化学成分、变质相及原岩特征进行分析与研究,结果表明彭家河石榴石矿床的含矿层位为水月寺群的周家河组,石榴石主要赋存于含(石墨)矽线石榴黑云斜长片麻岩及石榴黑云斜长片麻岩中,前者石榴石含量较高10%～50%,后者含量稍低12%～36%,X衍射及电子探针分析矿床中石榴石以铁铝榴石为主,其次是镁铝榴石,少量钙铝榴石.运用变质反应平衡温压方程计算出成矿温压条件为:P=600 MPa～800 MPa,T=650℃～750℃;变质相为高角闪岩相,高角闪岩相的富铁铝质沉积变质岩系--孔兹岩系是寻找此类石榴石矿床的重要找矿标志.     

安徽西部霍邱周油坊铁矿床地球化学特征及成因

周油坊铁矿床位于华北地台南缘皖西霍邱铁矿田中部,含矿地层位于新太古界变质岩系上部,矿石中的铁矿物主要为镜铁矿和磁铁矿。通过研究该矿床矿石和围岩的地球化学特征,探讨矿床的成矿物质来源、成矿古地理环境及富铁矿的成因。结果表明,周油坊矿床的主要成矿物质来源于混合了海底火山热液的高温海水,形成于大洋岛弧与大陆之间有陆源物质输入的弧后陆前还原海洋环境,初步认为该矿床为原始沉积变质型富铁矿。     

大阜山金红石矿床含矿岩体的形成变化及其与成矿的关系

通过对含矿岩体结构、产状、岩石类型、化学成分、微观特征,矿体产状、矿体与各类岩石的空间关系,矿石岩性观察研究,认为含矿岩体空间形态为向北东倾的椭圆柱形,原岩为辉长岩、成岩过程中物质成分发生了充分的分异富集,分异作用主要是重力分异、次为结晶分异;成岩后又经历了“角闪岩相→榴闪岩相→绿片岩相”的变质过程,三次变质作用均有金红石形成、第二次是主要成矿作用。分异作用奠定了成矿的物质基础、是矿体产状和矿石岩性的主因,变质作用使高钛岩石变为矿体。深部有一定找矿前景。     

南极拉斯曼丘陵长英质变质岩中磷灰石-斜方辉石组合的岩石学意义

南极拉斯曼丘陵高级长英质变质岩中出现的磷灰石-斜方辉石(Ap-Opx)组合表明岩石经历了麻粒岩相条件下的变质作用,长英质片麻岩发生了强烈的脱水深熔作用。随着熔体的迁出,长英质片麻岩中的残留或者镁铁质岩石中的分异产物,均可形成Ap-Opx组合。残留矿物如磷灰石、金属氧化物等具有丰富的稀土元素,强烈影响着岩石中的稀土元素配分型式。磷灰石-斜方辉石组合的存在说明体系中有适量但不是很充足的有效钙质组分。由磷灰石、磁铁矿-钛铁矿、石榴石,直至斜方辉石,一方面反映了活动组分-残留组分的不断变化,另一方面,也说明高级变质作用过程中体系的失水程度逐渐增加;变质作用中富含该组合的岩石是经变质过程形成的特有岩石,没有固有的原岩可对应。     

矿物成因族的演化及其地质找矿信息

基于对胶东、晋北寒武纪变质岩系、超基性岩、基性岩、花岗岩类、火山岩类、硅铁建造铁矿、金矿蚀变带内 1 1个不同地质产状的 34个角闪石、 2 51个绿泥石、 60个黑云母单矿物的提纯 ,矿物的共生组合、物理性质、化学成分、X光衍射分析、热分析、红外吸收光谱分析、双矿物地质温度计、矿物压力计的测定 ,提出了角闪石、绿泥石、黑云母矿物成因族的地壳物质演化、成岩成矿作用、变质岩原岩恢复、地层对比、变质相、蚀变带的演化规律和地质找矿信息。     

浙江省中部金矿带岩桨岩岩石化学判别分类法

概述自1982年初,我们开展“绍兴—诸暨—东阳北部金矿带成矿规律与找矿方向”的专题研究以来,对区内各大类岩浆岩进行了较详细的岩石学、岩石化学和岩石微量元素地球化学的研究,并对1100平方公里范围内的各类岩石进行了较准确的分类定名,及其含矿性的研究。由于本区广泛出露有各类区域变质岩系,根据所获研究成果,特别是对变质岩原岩恢复的一些研究成果认为,区内的变质岩的原岩,与本区所出露的各类岩浆岩(火山岩     

北祁连含蓝闪石岩的特征及成因

本文论述了北祁连含蓝闪石岩的岩石类型、原岩类型、特征矿物组合及产态.区内含蓝闪石岩的原岩包括优地槽内发育的各类富钠火山岩、含富钠火山质的沉积岩。在含蓝闪石岩分布区,岩石的变质相有葡萄石-绿纤石相、蓝闪石—绿片岩相、绿帘石-角闪岩相、铁铝榴石—角闪岩相等,未发现高压低温矿物组合.岩石应属区域动力变质作用产物,并对其形成环境进行了探讨.     

南秦岭下地壳组成及岩石圈的拆离俯冲作用

根据新提供的Pb同位素组成及岩石地球化学研究成果，本文进一步证实了位于北秦岭北界的明港地区发育的早中生代安山玄武质火山角砾岩岩筒所携带的下地壳捕虏体属于南秦岭。所恢复的南秦岭下地壳剖面自下而上为：底侵成因的变辉长岩-基性麻粒岩(其中含有榴辉岩及辉石岩的透镜体)-酸性麻粒岩。秦岭造山带总体的岩石因模型为：南秦岭(扬子块体)向北拆离俯冲，北秦岭地壳向华北仰冲，华北岩石因呈楔状插入秦岭造山带，拆离面约在中、下地壳之间。南秦岭俯冲岩片延伸的范围在平面上有可能达到400km。     

青藏高原综合观测研究站的回顾与展望

中国科学院青藏高原综合观测研究站从１９８８年建站到１９９８年以来,在各个方面均取得了长足的发展,横向生产性项目的开展和完成不仅解决了部队和地方的实际问题,而且缓和了观测研究站在运行过程中所面临的经费严重不足的问题,同时也为我所冻土专业研究人员提供了在生产中实践的机会,在基础理论研究方面,承担了国家攀登计划项目,国家基金项目,中国科学院重点项目和中国科学院冰冻圈专项项目等的研究工作,在多年冻土变化,     

Principles of spatial organization and evolution of the biosphere and the noosphere

In his last lifetime essay, “A Few Words about the Noosphere”, Academician V.I. Vernadsky (1944) wrote that all living organisms on the planet, including man, are integral to the biosphere of the Earth, its material and energy structure and cannot be physically independent of it even for a minute. However, the substrate that generates all living beings and is no less tightly bound to the biosphere has always been characterized by a significant geochemical heterogeneity, traced both in the vertical and in the lateral structure of all geospheres.

The present work is devoted to three most important aspects of modern geochemistry and biogeochemistry:

• — evolution of the ecological and geochemical state of the environment under conditions of a virgin (anthropogenically untouched) biosphere;
• — structural features of the geochemical organization of the modern noosphere;
• — specificity of the interaction of living matter with the environment under increasing anthropogenic load.

On the basis of theoretical concepts of biogeochemistry and geochemical ecology, formulated in the works of V.I. Vernadsky, A.P. Vinogradov, A.E. Fersman, B.B. Polynov, A.I. Perel’man, M.A. Glazovskaya, V.V. Kovalsky, E. Odum, B. Commoner, E.I. Kolchinskii and others, the author puts forward a hypothesis that there exist two qualitatively different stages in the evolution of the biosphere.The first stage is recognized as the period of natural evolution of the biosphere during which it evolves successively into a more complex and more biogeochemically specialized object. In the course of the geological time, this constantly results, on the one hand, in an increase in species diversity and the perfection of individual species, and, on the other hand, to directed improvement and a greater differentiation of the geochemical conditions of the environment. At this stage, the evolution of all systems of the biosphere that were controlled by the mechanisms of self-organization and self-regulation resulted in the establishment of a dynamic equilibrium, which was responsible for the cycling of all essential chemical elements and therefore providing ecologically optimal geochemical conditions in all ecological niches and for all species and biocenoses inhabiting the biosphere at any given moment.The beginning of the second stage is related to the appearance of reason and qualitative changes in the biosphere caused by the goal-directed activity of the human mind, as an entirely new geological force that appeared to be able not only to disrupt the functioning of natural mechanisms of self-regulation and selforganization, but also to transform the environment in the intersts of a single biological species, Homo sapiens. A direct consequence of this change was the uncontrolled transformation of the natural environment, during which the primary structure (geochemical background) created in the course of billions of years was eventually superimposed by a qualitatively new layer of anthropogenically-derived chemical elements and compounds, thus building an interference pattern of a new geochemical field with which practically all modern living organisms are now forced to interact.An outstanding feature of the new evolutionary stage of the natural environment, called by Vernadsky the noosphere, is that biogeochemical changes at this stage proceed at a rate which exceeds that required for the living matter to adapt to these changes. The result is the disruption of the existing parameters of the biological cycle, leading to the emergence of a significant number of endemic diseases of geochemical nature.The proposed approach was used to prove the anthropogenic genesis of existing geochemical endemic diseases and explain the mechanisms of their appearance. In addition, this approach allowed us to develop a new methodology for mapping zones of ecological and geochemical risk and noticeably simplify the procedure of monitoring distribution and prevention of all diseases of geochemical nature.     

铀钍的地球化学及对地壳演化和生物进化的影响

本文论述了在含挥发份和贫挥发份条件下Ｕ、Ｔｈ的迁移行为及其对地球和行星演化的影响,并阐述了造成地球独特地质演化历史的原因。提出了Ｕ、Ｔｈ在地球中的迁移模式以及该模式对地壳形成、演化的控制作用和对生物发展演化的可能影响。     

Palaeoecology and the origin of the coconut

While botanists, archaeologists, historians and linguists have contributed to the debate on the origin of the coconut pollen analysts have been silent. This article attempts to integrate the results of recent palaeoecological research with findings from the other disciplines.     

共和盆地层状地貌系统与青藏高原隆升及黄河发育

利用卫星遥感影像,结合实地调查和测年结果,对共和盆地层状地貌系统进行了解译、分析。研究表明,共和盆地层状地貌系统由山麓剥蚀面、洪积扇面、盆地面以及黄河阶地面构成,其空间结构、物质组成对发生于早更新世早期的青藏运动C幕和中更新世末期的共和运动反映清晰。青藏运动C幕使青藏高原主夷平面在高原差异性隆升中彻底解体,垂直变形量高达1700m。共和运动使黄河在0.11Ma进入共和盆地,其后黄河平均以3.5mm/a的侵蚀速率下切盆地,同时在盆地边部的山前古冲洪积扇以大致相近的速率被抬升,最终导致高差在2000m左右的层状地貌系统的出现。     

Wavelets and the Generalization of the Variogram

The experimental variogram computed in the usual way by the method of moments and the Haar wavelet transform are similar in that they filter data and yield informative summaries that may be interpreted. The variogram filters out constant values; wavelets can filter variation at several spatial scales and thereby provide a richer repertoire for analysis and demand no assumptions other than that of finite variance. This paper compares the two functions, identifying that part of the Haar wavelet transform that gives it its advantages. It goes on to show that the generalized variogram of order k=1, 2, and 3 filters linear, quadratic, and cubic polynomials from the data, respectively, which correspond with more complex wavelets in Daubechies's family. The additional filter coefficients of the latter can reveal features of the data that are not evident in its usual form. Three examples in which data recorded at regular intervals on transects are analyzed illustrate the extended form of the variogram. The apparent periodicity of gilgais in Australia seems to be accentuated as filter coefficients are added, but otherwise the analysis provides no new insight. Analysis of hyerpsectral data with a strong linear trend showed that the wavelet-based variograms filtered it out. Adding filter coefficients in the analysis of the topsoil across the Jurassic scarplands of England changed the upper bound of the variogram; it then resembled the within-class variogram computed by the method of moments. To elucidate these results, we simulated several series of data to represent a random process with values fluctuating about a mean, data with long-range linear trend, data with local trend, and data with stepped transitions. The results suggest that the wavelet variogram can filter out the effects of long-range trend, but not local trend, and of transitions from one class to another, as across boundaries.