内蒙古苏尼特左旗地区堆晶角闪辉长岩的发现及地质意义   总被引：6，自引：0，他引：6  

李玉文  邓晋福 《现代地质》1995,9(2):212-219

通过详细的野外工作和室内研究，发现苏尼特左旗附近较广泛地分布有一种主要由角闪石和外长石组成的堆晶岩，其化学成分属基性岩范畴，可定名为堆晶角闪辉长岩。这类岩体具清楚的层状构造、堆晶结构．岩石化学成分、稀土元素、结构和构造等特征均表明，该类岩石是由富水的拉斑玄武岩浆经分离结晶作用形成的，是造山带火成岩组合中的一个主要组成部分，形成于造山构造岩浆旋回的早期阶段。  相似文献   

蒋家沟泥石流堆积物的时代及成因     

雷祥义  李昭淑 《山地学报》1993,(3)

据石英ESR和~14C测年结果,蒋家沟泥石流堆积可分为晚更新世形成的古泥石流堆积和近代泥石流堆积两类。古泥石流堆积再分为早、中、晚三期。扫描镜下观察蒋家沟古泥石流堆积中的石英砂表面机械结构特征和现代泥石流十分相同,例如两者的颗粒都呈尖锐棱角状,粒面上均发育很好的贝壳状断裂结构、解理面、凹坑、擦痕(或擦沟)等,这表明二者的形成环境是相同的。  相似文献   

Multiple Forward Scattering of Surface Waves: Comparison With an Exact Solution and Born Single-Scattering Methods   总被引：2，自引：0，他引：2  

Wolfgang Friederich  Erhard Wielandt  Stefan Stange 《Geophysical Journal International》1993,112(2):264-275

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用单钻孔资料和岩层复平求面理倾斜的通用公式探讨          下载免费PDF全文

张伯南 《地质科学》1990,(1):98-100

用改进的数学公式,便于用单钻孔资料和岩层复平求面理倾斜、求岩层厚度、求地层断距等多个课题。  相似文献   

硅酸盐固溶体矿物中组分的韵律型空间分布及形成过程中的时-空自组织     

吴金平  王江海 《矿物学报》1990,(3)

本文根据熔体聚合模型和正规溶液模型,建立了非平衡条件下,在二组分硅酸盐熔体固结过程中的非平衡非理想界面反应的非线性动力学模型:对上式进行数值模拟表明,当W/RT<-2时,有三重态,并通过建立界面状态(组成)的质量守恒方程,合理地说明了硅酸盐固溶体矿物韵律结构形成的可能机理之一,寻找界面反应三重态是研究固溶体矿物韵律结构的一条相当普遍的途径。  相似文献   

Petrology of spinel granulites from Araku, Eastern Ghats, India, and a petrogenetic grid for sapphirine-free rocks in the system FMAS   总被引：4，自引：0，他引：4  

P. SENGUPTA  S. KARMAKAR  S. DASGUPTA  M. FUKUOKA 《Journal of Metamorphic Geology》1991,9(4):451-459

Abstract Spinel-quartz-cordierite and spinel-quartz are found as relic prograde assemblages in Fe-rich granulites from the Araku area, Eastern Ghats belt, India. Subsequent reactions produced orthopyroxene + sillimanite in the former association and garnet + sillimanite in the latter. The first reaction is univariant in the FMAS system, but is trivariant in the present case because of the presence of Zn and Fe³⁺ in spinel. The second reaction also has high variance because of Zn and Fe³⁺, but also because of the presence of Ca in garnet. Thermobarometry shows that the metamorphic conditions were approximately 950° C and 8.5 kbar and the fo ₂ was near the NNO buffer. In Fe-rich bulk compositions and low- P -high- T conditions of metamorphism, two of the univariant reactions around the invariant point [Sa], namely (Sa, Hy) and (Sa, Cd), change topology due to reverse partitioning of Fe-Mg between coexisting garnet and spinel. An alternative partial petrogenetic grid in the system FMAS is constructed for such conditions and is applied satisfactorily to several sapphirine-free spinel granulites. It is shown that bulk composition ( X _Fe and Zn) exerts greater control on the stability of spinel + quartz than fo ₂. The effect of the presence of Zn and Fe³⁺ in spinel on the proposed grid is evaluated. Reaction textures in the Araku spinel granulites can be explained from the petrogenetic grid as due to near-isobaric cooling.  相似文献   

新疆黄山杂岩体矿物学特征及其意义   总被引：1，自引：0，他引：1  

钟应先 《矿物岩石》1991,11(1):14-23

黄山杂岩体造岩矿物有橄榄石、斜方辉石、单斜辉石、斜长石、角闪石和黑云母。其中斜方辉石的多色性不是由Fe~(2+)引起,而是由Ti~(4+)引起。单斜辉石结晶后常与岩浆继续发生化学反应,形成一种岩浆岩结构——角闪反应补丁结构。橄榄石中镍含量的亏损程度反映杂岩体曾经历过硫化物熔离作用。单斜辉石Si,Al~Ⅳ,Ti的变化表明杂岩体属于拉斑玄武岩系列。超镁铁岩中K,Ba,Th,Hf等元素反常的地球化学行为是由该岩石中黑云母矿物引起。  相似文献   

区域化探异常研究方法探讨   总被引：1，自引：0，他引：1  

李武俊  唐开金 《陕西地质》1991,(1)

本文对区域化探异常图示、异常评序、可能成矿元素、综合解释及成矿预测等方面进行了探索性研究,这对异常深入的剖析研究,确定异常检查范围及成矿预测都十分有益。数据处理系统是在无 X—Y 绘图仪的 PC 微机上实现数据处理、成图及各类处理分析的程序软件。  相似文献   

STUDY ON CORRELATIVE EARTHQUAKES AND SEISMIC WINDOW NETWORK IN TIANSHAN REGION     

Wang Gulling Ao Xueming 《内陆地震》1991,(4)

In this paper , by using the seismic data of strong earthquake (M≥7) which have occurred since 1900,correlative features of strong earthquake activity in Tianshan region which crosses China and USSR have been studied . Meanwhile , we selected 15 seismic windows (11 in China , 4 in USSR) by censusing , systematically researching and statistically examing seismic data of regional seismic network which are in Chian and USSR.The anomalous features of seismic window and seismic window network , prediction index and prediction plan have been studied . In the same time ,its prediction efficency have been evaluated . Several examples of successful earthquake prediction are given out in this paper .Finally ,the possible physical mechanism of the results are discussed.  相似文献   

The influence of aerosol particle composition on cloud droplet formation     

A. Hallberg  J. A. Ogren  K. J. Noone  K. Okada  J. Heintzenberg  I. B. Svenningsson 《Journal of Atmospheric Chemistry》1994,19(1-2):153-171

A difference in partitioning between cloud droplets and interstitial air for two chemical species (elemental carbon and sulphur) with different expected behaviour in nucleation scavenging was observed in clouds at Mt. Kleiner Feldberg (825 m asl), near Frankfurt, Germany. The fraction of sulphur incorporated in cloud droplets was always higher than the fraction of elemental carbon. This difference in partitioning has also been observed in fog but under different pollution conditions in the Po Valley, Italy. Both these studies were based on bulk samples. In the present study at Kleiner Feldberg, impactor samples of the particles in the interstitial air and the cloud droplet residuals were taken and a single particle analysis was done on the samples. It was found that, for a given particle size, the majority of particles forming cloud droplets were soluble and that insoluble particles preferentially remained in the interstitial air.  相似文献