漾濞地震震源位置分析

采用一致的地震震相和台网布局，应用昆明数字地震台网资料，对2002年月1月4日－1月7日的漾濞地震及序列作进一步核定，得出了更精确的地震震源位置，并作出三维空间图。     

Development of site-specific design ground motions in Western and Eastern North America

This paper presents results recently obtained for generating site-specific ground motions needed for design of critical facilities. The general approach followed in developing these ground motions using either deterministic or probabilistic criteria is specification of motions for rock outcrop or very firm soil conditions followed by adjustments for site-specific conditions. Central issues in this process include development of appropriate attenuation relations and their uncertainties, differences in expected motions between Western and Eastern North America, and incorporation of site-specific adjustments that maintain the same hazard level as the control motions, while incorporating uncertainties in local dynamic material properties. For tectonically active regions, such as the Western United States (WUS), sufficient strong motion data exist to constrain empirical attenuation relations for M up to about 7 and for distances greater than about 10–15 km. Motions for larger magnitudes and closer distances are largely driven by extrapolations of empirical relations and uncertainties need to be substantially increased for these cases.

For the Eastern United States (CEUS), due to the paucity of strong motion data for cratonic regions worldwide, estimation of strong ground motions for engineering design is based entirely on calibrated models. The models are usually calibrated and validated in the WUS where sufficient strong motion data are available and then recalibrated for applications to the CEUS. Recalibration generally entails revising parameters based on available CEUS ground motion data as well as indirect inferences through intensity observations. Known differences in model parameters such as crustal structure between WUS and CEUS are generally accommodated as well. These procedures are examined and discussed.     

试述福建顺昌南舟萤石矿地质特征

顺昌南舟萤石矿位于顺昌县埔上镇南舟村境内，1996年福建省区域地质调查队开展1：5万埔上幅区调时发现矿体，后开展普查工作表明该矿床规模大、交通方便，易于开采，现已投入开发利用。南舟萤石矿成矿地质特征在闽北丰富的萤石资源中具有一定代表性。     

某地平板玻璃原料用石英砂的提纯研究

某地石英矿砂通过磁选分离法、稀酸浸泡法处理后，矿砂不同程度地降低了铁、铝、钙镁的含量；采用磁选分离 稀酸浸泡法联合处理后，使该地石英砂的化学成分达到了优质的生产平板玻璃用硅质原料的国家标准。     

公婆泉盆地局部排泄源氧化还原属性与铀矿化关系探讨

在系统分析公婆泉盆地地质背景、水文地质条件的基础上，对该区局部排泄源氧化还原属性与铀矿化的关系进行了探讨。研究结果表明，局部排泄源的存在对铀矿化具有重要作用，当局部排泄源属于还原性质时，铀矿体常常分布于该排泄源上游；若属氧化性质，排泄源铀矿体通常位于其下游或附近。公婆泉盆地存在相对氧化和相对还原的二种局部排泄源，北骆驼泉区的沙泉沟与平沙地、麻黄沟、北骆驼泉沟排泄源之间应为有利的铀矿化地段。     

Changes in source parameters of foreshocks and aftershocks of the 2001 M_S=6.0 Yajiang, Sichuan, earthquake

Introduction An MS=6.0 earthquake occurred on February 23, 2001 in Yajiang county, Sichuan Province. The earthquake is located on the east of the southeast segment of the Litang-Dewu fault with strike of NW. Before the event, on February 14, an MS=5.0 earthquake took place nearly in the same place. In 1948 an MS=7.3 earthquake occurred on the northwestern segment of the Litang fault. The length of the surface rupture belt caused by the earthquake is 70 km, which extended from Litang to…     

Magnetotelluric Investigation of the Hydrothermal System and Heat Source in the Muine-Toyoha Geothermal Area, Hokkaido, Japan

Abstract. Magnetotelluric (MT) surveys were carried out around the Muine volcano, Hokkaido, Japan, where it is expected that the heat and metal source forming the polymetallic Ag-Pb-Zn-Cu-In Toyoha deposit is present at depth. Measurements were performed at 20 sites, 18 of which were located along a WSW-ENE profile traversing the north ridge of Mt. Muine. A resistivity model obtained from 2D inversion of the MT data shows subsurface specific conductive and resistive features. Conductive layers are present at the surface of Mt. Muine. The low resistivity is probably due to the clay-rich rocks associated with the hydrothermal alteration. A high resistivity layer, which corresponds to the pre-Tertiary Usubetsu Formation, crops out east of Mt. Muine and dips westward. At the west foot of Mt. Muine, relatively high resistive layers are widely exposed. The resistivity increases with depth and exceeds 1000 ohm-m. This fact indicates that this region is not influenced by the recent hydrothermal activity. An extremely conductive zone about 3–6 km wide and 6–9 km thick exists at a depth of 2 km below Mt. Muine. This zone mostly corresponds to an elastic wave attenuation zone detected by a seismic survey. It is interpreted as a large hydrothermal reservoir or melted magma, which is a heat source of the hydrothermal system in this area.     

1991年江淮暴雨时期的能量和水汽循环研究

通过对 1991年 5～ 7月江淮暴雨期全球范围的水汽输送和不同降水过程中江淮暴雨区及其临近区域的水汽收支和视热源和视水汽汇的计算分析得到了以下结论 :( 1)从水汽输送的机制来看 ,一方面 ,有大量的水汽以定常涡动的方式从孟加拉湾及南海输送到中国江淮地区 ;另一方面 ,江淮地区的瞬变涡动水汽向北输出 ,这可能与江淮地区频繁活动的α和β中尺度系统有关 ,它们将江淮地区汇集的充沛的水汽除了大部分以降水形式降下外 ,剩余部分继续向水汽较少的高纬地区输出 ,以维持全球水汽的平衡。( 2 )在降水过程中 ,局地蒸发项在水汽的供应中或再循环中十分重要 ,其数值一般为降水量的 13 ～ 12 ,这与1998年的降水情况相似。( 3 )在降水过程中 ,暴雨区的水汽主要是从南边界和西边界流入的 ,东边界和北边界则流出 ,并且水汽的流入、流出主要在中低层进行。 (a)在流入边界上 ,水汽通量的垂直分布存在差异 ,暴雨区西边界和南边界的水汽流入的垂直差异可能与其所在的地理位置有密切关系。 (b)对于暴雨区 ,不同强度的降水过程水汽的主要来源有所不同。( 4)在 5次降水过程中 ,视热源和视水汽汇的较大值对应降水的大值区 ,表明了水汽凝结加热对大气加热所起的主要作用。梅雨期降水 ,以对流性降水为主 ,对流活动随季节变化     

超积累植物与找矿

本文介绍了超积累植物的概念和它在地质找矿中的意义,回顾了国外超积累植物的研究历史,并对应用超积累植物进行找矿的发展方向进行了讨论。