从南通地形变等变化探讨地震短临预报的可能途径     

张绍治  范桂英 《内陆地震》1992,6(3):281-286

1990年2月10日常熟——太仓5.l级地震前,南通等地形变等前兆手段异常明显。震例资料揭示,此次地震敏感部位的形变等前兆变化可区分出阶段性。据此作者探讨了形变短临地震预报的可能途径。  相似文献   

A visco-elastoplastic model for fault rocks and its application to earthquake research     

Liming Zhang  Zhenyu Tao 《地震学报(英文版)》1992,5(4):667-674

In the light of the rheological properties of crustal rocks and some features of earthquakes, a rheological model for fault rocks is suggested in the paper and the possibility of applying the suggested model to the study of earthquake mechanism is discussed. The results show that it is reasonable to take the suggested model as a physical simplification of fault rocks and to apply it to the numerical calculation and simulation of 2-D problems. The Chinese version of this paper appeared in the Chinese edition ofActa Seismologica Sinica,14, 129–136, 1992.  相似文献   

湘中下石炭统测水组沉积层序及幕式聚煤作用   总被引：11，自引：0，他引：11  

邵龙义  张鹏飞等 《地质论评》1992,38(1):52-59

下石炭统测水组是我国南方主要含煤地层之一，煤系及煤层在湘中地区发育最佳，该区测水组形成于碎屑滨岸障壁－泻湖沉积体系中。文中对测水组沉积层序及其所反映的海平面变化历史进行了分析，提出测水组上段底部砂岩是海侵背景下形成的障壁砂坝或障璧岛，其底部侵蚀面是海侵冲刷面（ravinement surface)。同时提出测水组下段三、五煤层的形成与受海平面变化控制的幕式聚煤作用（episodie coal accumulation)有关，后者系指海平面下降阶段横跨不同相区的区域性聚煤作用。  相似文献   

岩爆烈度分级问题   总被引：7，自引：0，他引：7  

谭以安 《地质论评》1992,38(5):439-443

在指出前人岩爆烈度划分所存在主要问题的基础上,本文提出了岩爆烈度新的分级原则、依据,以及新的烈度分级;同时总结了岩爆防治的有关措施。  相似文献   

冰川积累量测量和计算方法研究     

杨大庆 Elder  K 《冰川冻土》1992,14(1):1-10

  相似文献   

天然淡水冰单轴压缩强度及其温度和应变率效应     

沈乐天  赵士达  卢锡年  史毓香  陈淑霞 《冰川冻土》1990,(4)

本文报道了在不同温度和不同应变率下天然淡水冰单轴压缩强度的实验结果。指出S—l型柱状晶粒冰的压缩强度随着温度的降低而增加,极限压缩强度在应变率为10~(-4)S(-1)时有一个最大值。本实验的应变率范围是10~(-5)—10~0s~(-1)。10~(-1)—10~0s~(-1)的应变率范围是在冲击速度lm/s左右的实验条件下获得的,这个速度接近于浮冰与海上结构物相撞的情况。以本实验为基础,有希望发展对海冰的实验技术。  相似文献   

Ri-μi/μm-Ci dependent oblateness of deformed pebbles in the Baraitha conglomerate,Central India and tectonic implications     

Prakash P. Roday  Gopal Maheshwari  Narendra H. Vaghmarey 《Journal of Earth System Science》1990,99(2):321-338

Strain analysis of the Baraitha conglomerate is attempted by direct measurements on extracted pebbles and by micrometric analysis. The overall deformation is of flattening type, with thek value lower by more than half in the matrix than in the pebbles. The viscosity contrast between pebbles and matrix (μ _i/μ_m) is in the ratio of 2:1 and the bulk deformation appears to be strongly controlled by C_i (concentration of pebbles expressed as percentage). The total shortening (≃35%) in the Baraitha conglomerate is comparable with the shortening accomplished in the folding of the overlying Bijawar Group volcanosedimentary sequence. The bulk strain axesX _t, Y_t andZ _t, as determined from the analysis of the deformed conglomerate, are unsymmetrically oriented with reference to folds formed by oblique flexural-slip with neitherX _t norY _tcoincident with the fold hinges. The lack of transection of folds by cleavage again suggests flattening deformation. The extension in theY _tdirection is greater in the matrix than in the pebbles.  相似文献   

地质力学在塔里木盆地找油工作中的应用——纪念李四光教授诞生100周年   总被引：1，自引：0，他引：1  

康玉柱 《新疆地质》1990,(1)

运用李四光教授所创立的地质力学理论和方法,对塔里木盆地进行了石油地质研究和油气勘查工作.①系统地研究了塔里木盆地的成生发展历史及构造体系的划分;②运用地质力学理论和方法,对确定含油气区—选择油气富集带—寻找油气田—评价油气田全过程进行实践,并取得重大突破,进一步证实沙雅隆起是一个油气富集带;③首次实现了我国古生代海相油气田的重大突破;④初步总结了构造体系控油的几点规律.  相似文献   

大陆裂谷区幔源矿物橄榄石在不同应变阶段的位错构造及位错滑移系研究——以法国中央地块及中国汉诺坝新生代玄武岩的二辉橄榄岩包体为例     

周梅馨  许志琴  陈方远 《岩石矿物学杂志》1990,9(1):47-54

利用透射电子显微术(TEM)对两个新生代裂谷区的碱性玄武岩(法国中央地块克莱蒙菲朗及中朝板块北部河北万全)中幔源矿物橄榄石的位错亚构造进行研究,通过位错类型、衍射花样、柏格斯矢量及位错滑移系的分析及计算,判断了深源包体从上地幔进入地壳的动力学过程——经历了高温(>1000℃)蠕变、低温(<600℃—800℃)应变及后期局部温度回升阶段,确定了高温滑移系以{OKl}[100]及(001)[100]为主,并存在由(010)[001]及(100)[001)滑移系组成的高温位错网络,计算了低温应变的滑移系为(110)[001]及(010)[001]。  相似文献   

Quaternary changes in delivery and accumulation of organic matter in sediments of Lake Biwa, Japan     

Philip A. Meyers  Keiji Takemura 《Journal of Paleolimnology》1997,18(3):211-218

A 911-m-long sediment core from Lake Biwa, Japan, provides a record of organic matter delivery and accumulation in this large lake during a succession of tectonic and climatic changes dating back to the latest Pliocene. Sediments deposited since 430 ky are profundal; older sediments vary in setting between shallow-water and fluviodeltaic conditions, with occasional deep-water intervals. C/N ratios identify algal production as the dominant source of organic matter throughout the core, although the proportion of land-derived contributions episodically increases in the fluviodeltaic and shallow-water sediments. Rates of organic matter delivery and burial in lake sediments change in response to glacial-interglacial climate changes over the past 430 ky. Sediments deposited during interglacial intervals have organic carbon mass accumulation rates up to 9 times greater than those from glacial intervals, reflecting interglacial climates that were wetter than glacial climates. Algal production of organic matter increased during interglacial times because of greater wash-in of soil nutrients, and organic matter preservation was enhanced because of faster sedimentation rates.  相似文献