圣安德烈亚斯断层     

《地图》2014,(4):8-9

圣安德烈亚斯断层（San Andreas Fault）,长约1300公里,横跨美国加利福尼亚州西部和南部,以及墨西哥下加利福尼亚州的北部和东部。1895年,加利福尼亚大学地质学教授安德鲁·劳森（Andrew Lawson）发现并命名了圣安德烈亚斯断层。  相似文献   

Power-law Distribution of Normal Fault Displacement and Length and Estimation of Extensional Strain due to Normal Faults:A Case Study of the Sierra de San Miguelito, Mexico     

A. F. NIETO-SAMANIEEGO  S. A. ALANIZ-LVAREZ 《《地质学报》英文版》2005,79(1):36-42

The Sierra de San Miguelito is a relatively uplifted area and is constituted by a large amount of silicic volcanic rocks with ages from middle to late Cenozoic. The normal faults of the Sierra de San Miguelito are Domino-style and nearly parallel. The cumulative length and displacement of the faults obey power-law distribution. The fractal dimension of the fault traces is -1.49. Using the multi-line one-dimensional sampling, the calculated exponent of cumulative fault displacements is -0.66. A cumulative curve combining measurements of all four sections yielded a slope of -0.63. The displacement-length plot shows a non-linear relationship and large dispersion of data. The large dispersion in the plot is mainly due to the fault linkage during faulting. An estimation of extensional strain due to the normal faults is ca. 0.1830.The bed extension strain is always less than or equal to the horizontal extension strain. The deformation in the Sierra de San Miguelito occurred near the surface, producing pervasive faults and many faults are too small to appear in maps and sections at common scales. The stretching produced by small faults reach ca. 33% of the total horizontal elongation.  相似文献   

1969年坠地陨石中发现45亿年前最古老矿物     

孝文 《地理教学》2012,(14):62-62

新浪科技讯北京时间7月2日消息,据国外媒体报道,1969年,一颗陨星划过墨西哥夜空,在北部奇瓦瓦州坠地后分裂成数千块陨石,被称之为阿伦德陨石。最近,美国科学家在对阿伦德陨石进行研究时发现了一种新的矿物,被命名为“盘古石”（Panguite）。盘古石据信是太阳系内最古老的矿物之一,拥有大约45亿年历史。盘古石是一种难熔矿,只能在太阳系早期的极端温度和环境下形成。  相似文献   

Processing of Aerosol Particles in Convective Cumulus Clouds: Cases Study in the Mexican East Pacific     

Jose C. JIMENEZ-ESCALONA  Oscar PERALTA 《大气科学进展》2010,27(6):1331-1343

In the Mexican Intertropical Convergence Zone, particle size distributions within 500 m of cloud boundaries at altitudes of 1000, 2500, and 4200 m, were compared against size distributions at the same levels but 1500 m away from the clouds. The differences in the distributions near and far from the cloud are related to processes that may change particle properties inside the cloud. Chemical changes in the aerosols are deduced from the particles’ refractive index, as derived from comparisons with the scatter...  相似文献   

稀土危局截改出口政策延伸产业链势在必行     

《国土资源》2012,(2)

一度闹得沸沸扬扬的中国9种原材料出口限制措施争端案,最近有了最终裁决。而这一裁决也将中国稀土推上了风口浪尖。日前,世贸组织（WTO）上诉机构就美国、欧盟、墨西哥诉中国原材料出口限制措施争端案发布裁决报告,即中国以环境为由限制9种原材料出口的关税、配额及其他一些政策均不合理。  相似文献   

走向全球——《非开挖技术》采访ISTF执行主管John Hemphill     

Ryan  ;Sweeney  ;王轲译  ;胡远彪校 《岩土钻凿工程》2009,(5):2-4

2000年起,John Hemphill曾作为NASTF（北美非开挖协会）执行主管——帮助提升美国、加拿大和墨西哥的业务。在2008年初,Hemphill成为ISTT（国际非开挖协会）的执行主管,向更多的全球观众展示他的风采。在与《非开挖技术》一对一的采访中,Hemphill谈论了他调任到ISTT和在组织机构中的新角色,以及国际非开挖市场和这项产业的前景。  相似文献   

第八届国际地面沉降学术研讨会明年将在墨西哥举行     

《中国地质灾害与防治学报》2009,20(4):94-94

第八届国际地面沉降学术研讨会（Eighth International Symposiumon Land Subsidence,EISOLS 2010）将于2010年10月17～22日在墨西哥克雷塔罗市（Queretaro,Mexico）召开。本届会议主题是：“地面沉降,开发自然资源引发的灾害及其影响”。  相似文献   

墨西哥中新生代岩浆活动规律及成矿研究          下载免费PDF全文

王力圆  邱瑞照  王翠芝  林木森  谢其锋  杨波 《地质找矿论丛》2017,32(4):667-675

墨西哥中新生代岩浆作用与太平洋板块向东俯冲消减作用及晚白垩-始新世的拉腊米期造山运动有关,岩浆作用控制了矿床的分布规律。文章通过综合分析大量墨西哥中新生代岩浆岩和矿床资料,讨论了岩浆活动规律及构造活动和成矿作用的关系。墨西哥主要有5个岩浆活动时期,分别为晚古生代岩浆作用、早-中侏罗世岩浆作用、白垩世岩浆作用、古近纪岩浆作用、中新世岩浆作用。墨西哥的成矿作用主要与拉腊米期岩浆活动有关(约80 Ma—40 Ma),中新生代的矿床明显分成晚侏罗世(J3)、早白垩世(K1)、晚白垩世(K2)、古新世(E1)、始新世(E2)、渐新世(E3)、中新世(N1)等地质时期。古太平洋板块、法拉隆板块和科科斯板块等三大板块俯冲消减形成3个俯冲成矿系列,即从沿海到内陆依次发育有IOCG型铁铜金成矿带→斑岩型铜钼金成矿带→浅成低温热液型银金多金属成矿带,分别代表太平洋古板块、法拉隆板块和科科斯板块向北美板块从俯冲挤压到碰撞后伸展的岩浆成矿环境。  相似文献   

近期地震活动是否异常? 科学家给出否定回答     

孙振凯 《国际地震动态》2010,(4):19-19

2010年4月14日发生在中国的Mw6．9级地震惨剧和近期发生在海地、智利、墨西哥以及其他地方的毁灭性地震使很多人产生了这样的疑问：这种地震活动是否异常？  相似文献   

Driving factors for forest fire occurrence in Durango State of Mexico: A geospatial perspective   总被引：3，自引：2，他引：1  

Diana Avila-Flores  Marin Pompa-Garcia  Xanat Antonio-Nemiga  Dante A Rodriguez-Trejo  Eduardo Vargas-Perez  Javier Santillan-Perez 《中国地理科学(英文版)》2010,20(6):491-497

Forest fire is one of the major causes of forest loss and therefore one of the main constraints for sustainable forest management worldwide. Identifying the driving factors and understanding the contribution of each factor are essential for the management of forest fire occurrence. The objective of this study is to identify variables that are spatially related to the occurrence and incidence of the forest fire in the State of Durango, Mexico. For this purpose, data from forest fire records for a five-year period were analyzed. The spatial correlations between forest fire occurrence and intensity of land use, susceptibility of vegetation, temperature, precipitation and slope were tested by Geographically Weighted Regression (GWR) method, under an Ordinary Least Square estimator. Results show that the spatial pattern of the forest fire in the study area is closely correlated with the intensity of land use, and land use change is one of the main explanatory variables. In addition, vegetation type and precipitation are also the main driving factors. The fitting model indicates obvious link between the variables. Forest fire was found to be the consequence of a particular combination of the environmental factors, and when these factors coexist with human activities, there is high probability of forest fire occurrence. Mandatory regulation of human activities is a key strategy for forest fire prevention.  相似文献