大别造山带超高压变质岩折返隆升的地层学证据—毛坦厂组榴辉岩砾石的启示   总被引：23，自引：0，他引：23  

李双应  王清晨等 《地质论评》2002,48(4):345-352

大别山北缘地区发育厚达近万米的中新生代碎屑岩，它们记录着大别山造山带和在株罗纪以来的演化历史。在安徽省六安地区毛坦厂组中，发现多块榴辉岩砾石。砾石新鲜，质地坚硬，表明属于第一旋回砾石。榴辉岩由石榴子石、多硅白云母、绿帘石、石英、金红石等组成。具有明显的退变质作用，发育以钠长石和闪石类组成的后合成晶、以及石榴子石周边的次为边。石榴子石以铁铝榴石和钙铝榴石为主，恪地C类榴辉岩。根据其特征应该属于大别山南部和北部超高压榴辉岩。毛坦厂组层位确切，古生物化石和同位素年龄都表明以晚株罗世为主，这一发现表明，在晚株罗世，以榴辉岩为代表的造山带根部物质，即：超高压变质岩已经出露地表，并作为毛坦厂组的物源。因此，大别造山带超高压为质岩折返到地表，最迟在晚株罗世。  相似文献   

Wedge Stability Analysis Considering Dilatancy of Discontinuities   总被引：6，自引：1，他引：6  

Y.-J. Wang  J.-H. Yin 《Rock Mechanics and Rock Engineering》2002,35(2):127-137

  相似文献   

Guanling Biota: A Rare Biota in Sea Early Late Triassic   总被引：1，自引：0，他引：1  

Wang Shangyan  Wang Yangeng  Wang Liting  Yin Gongzheng 《中国地质大学学报(英文版)》2002,13(3)

Guanling biota has been found at the bottom of Wayao Formation of Upper Triassic (Carnic stage) near Xinpu town, Guanling County, Guizhou Province, China. There are a lot of crinoids and marine reptiles, which is a characteristic of Guanling biota, including ammonites, bivalve, brachiopod, fish, conodont and plant. These fossils are featured not only with the large quantity, but also with their extraordinary perfect forms. This paper explores the meaning, geological background, present situation of study and scientific significance of Guanling biota.  相似文献   

Simulation of the Load-Unload Response Ratio and Critical Sensitivity in the Lattice Solid Model   总被引：4，自引：0，他引：4  

P. Mora  Y. C. Wang  C. Yin  D. Place  X. C. Yin 《Pure and Applied Geophysics》2002,159(10):2525-2536

— The Load-Unload Response Ratio (LURR) method is an intermediate-term earthquake prediction approach that has shown considerable promise. It involves calculating the ratio of a specified energy release measure during loading and unloading where loading and unloading periods are determined from the earth tide induced perturbations in the Coulomb Failure Stress on optimally oriented faults. In the lead-up to large earthquakes, high LURR values are frequently observed a few months or years prior to the event. These signals may have a similar origin to the observed accelerating seismic moment release (AMR) prior to many large earthquakes or may be due to critical sensitivity of the crust when a large earthquake is imminent. As a first step towards studying the underlying physical mechanism for the LURR observations, numerical studies are conducted using the particle based lattice solid model (LSM) to determine whether LURR observations can be reproduced. The model is initialized as a heterogeneous 2-D block made up of random-sized particles bonded by elastic-brittle links. The system is subjected to uniaxial compression from rigid driving plates on the upper and lower edges of the model. Experiments are conducted using both strain and stress control to load the plates. A sinusoidal stress perturbation is added to the gradual compressional loading to simulate loading and unloading cycles and LURR is calculated. The results reproduce signals similar to those observed in earthquake prediction practice with a high LURR value followed by a sudden drop prior to macroscopic failure of the sample. The results suggest that LURR provides a good predictor for catastrophic failure in elastic-brittle systems and motivate further research to study the underlying physical mechanisms and statistical properties of high LURR values. The results provide encouragement for earthquake prediction research and the use of advanced simulation models to probe the physics of earthquakes.  相似文献   

成都市土地利用现状遥感调查研究   总被引：2，自引：0，他引：2  

王军  吴传智  印仁高  刘智 《四川地质学报》2002,22(3):184-187

利用美国陆地卫星TM遥感图像资料，对成都市土地利用现状进行调查研究，全面系统地查明了成都市土地利用状况及其分布规律，分析与评价了土地利用的合理程度，揭示了土地利用中存在的主要问题，并提出了土地资源可持续利用的对策与建议，可为政府有关部门合理利用土地资源，制定国土整治规划提供科学依据。  相似文献   

黄骅坳陷港西开发区新近系明化镇组沉积微相三维建模   总被引：9，自引：3，他引：9       下载免费PDF全文

武军昌  吴胜和  尹伟  卢凤鸣  石占中  窦松江 《古地理学报》2002,4(4):39-46

本文以黄骅坳陷港西开发区为例，探讨在油田开发阶段，如何通过密井网区沉积微相定量几何学数据对新近系明化镇组沉积环境相似的稀井网区进行沉积微相三维建模的方法。密井网区研究表明，港西开发区河流相的单河道砂体宽度约50-300 m，一般为100-200 m，厚度约5-15 m，一般为6-10 m；漫溢砂体长、宽一般小于200 m；砂体结构主要为迷宫状和拼合板状两种型式。应用密井网区沉积微相定量几何学数据，采用标点过程方法，对井网较稀的目标研究区进行了三维沉积微相建模研究，并取得了良好的应用效果。  相似文献   

北太平洋冬季阻塞性高压对船舶西行航线的影响*          下载免费PDF全文

尹尽勇杜秉玉  李泽椿齐桂英 《应用气象学报》2002,13(6):704-710

通过对近10年北太平洋冬季阻塞性高压的建立、维持及崩溃的天气形势分析，结合船舶气象导航的原理、气象航线的设计以及影响航线选择的因素，指出了有利于北太平洋冬季西行高纬度航线的阻塞高压形式，为船舶西行选择高纬度航线提供了气象理论依据。  相似文献   

Load-Unload Response Ratio and Accelerating Moment/Energy Release Critical Region Scaling and Earthquake Prediction   总被引：20，自引：0，他引：20  

X. C. Yin  P. Mora  K. Peng  Y. C. Wang  D. Weatherley 《Pure and Applied Geophysics》2002,159(10):2511-2523

-- The main idea of the Load-Unload Response Ratio (LURR) is that when a system is stable, its response to loading corresponds to its response to unloading, whereas when the system is approaching an unstable state, the response to loading and unloading becomes quite different. High LURR values and observations of Accelerating Moment/Energy Release (AMR/AER) prior to large earthquakes have led different research groups to suggest intermediate-term earthquake prediction is possible and imply that the LURR and AMR/AER observations may have a similar physical origin. To study this possibility, we conducted a retrospective examination of several Australian and Chinese earthquakes with magnitudes ranging from 5.0 to 7.9, including Australia's deadly Newcastle earthquake and the devastating Tangshan earthquake. Both LURR values and best-fit power-law time-to-failure functions were computed using data within a range of distances from the epicenter. Like the best-fit power-law fits in AMR/AER, the LURR value was optimal using data within a certain epicentral distance implying a critical region for LURR. Furthermore, LURR critical region size scales with mainshock magnitude and is similar to the AMR/AER critical region size. These results suggest a common physical origin for both the AMR/AER and LURR observations. Further research may provide clues that yield an understanding of this mechanism and help lead to a solid foundation for intermediate-term earthquake prediction.  相似文献   

克孜尔水库大坝的地震安全性评估   总被引：1，自引：0，他引：1  

尹力峰  唐丽华  吴晓莉  赵纯青  王海涛  王坚  胡军  柏美祥  安景生  袁峡 《华南地震》2002,22(1):28-40

通过对克孜尔水库地震活动和地震地质构造背景，地震危险性，地震动力反应等的分析，评估土坝的抗震性能与安全性，并对大坝及库区周围的地质灾害进行了预测。  相似文献   

Study on Paleoenvironment since Late GlacialEpoch in Lanzhou Area, China     

Yang Guifang Yin Hongfu Li ChanganFaculty of Earth Sciences  China University of Geosciences  Wuhan 《中国地质大学学报(英文版)》2002,(1)

The Hongzuisi Section in Lanzhou area is used to infer the paleoclimate since the late glacial epoch. Through combined analysis of organic carbon isotope and CaCO3 content, paleoenvironment evolution of Hongzuisi Section since the late glacial epoch is discussed. There were changes in both dry-moist and warm-cold. Especially the climate changes can be compared with synchronous sections of other areas, which provides useful information for our future forecast.  相似文献