川滇地区现今块体水平运动变形特征分析

依据川滇地区1991，1999和2001年GPS测量数据，利用DDA正分析基本原理，结合现有的地质资料，对该地区近年来的水平构造运动特征进行了模拟分析，认为川滇地区水平运动整体速率在1999～2001年期间明显减弱；川滇决体主压应变以顺时针旋转为主，方向为SE—SEE；其南部是运动变形相对剧烈、易于积累能量的区域；未来一两年内，该地区地震活动水平不会太高。     

Peak displacement demand of small to moderate magnitude earthquakes in stable continental regions

A theoretical fault‐slip model has been developed for predicting the notional peak displacement demand (PDD) of earthquakes based on a limiting natural period of 5 s, for application in stable continental regions (SCRs). The developed theoretical expression is simple and robust. Importantly, it envelops predictions arising from a number of existing empirical and seismological (stochastic) models included in the comparison. The notional PDD prediction has been made initially for hard rock crustal conditions and at a reference source–site distance of 30 km. Factors have accordingly been introduced to correct for different distances and geological conditions in completing the PDD prediction model. Assuming displacement‐controlled behaviour, the predicted notional PDD may be compared with the displacement capacity of a structure, or component, for purposes of seismic stability assessment. Copyright © 2005 John Wiley & Sons, Ltd.     

Numerical analysis of contemporary hori-zontal tectonic deformation fields in China from GPS data

Introduction To correctly understand the tectonic deformation of continental lithosphere, its dynamical mechanics and seismic activity, we should firstly acquire the velocity field and strain field of lithospheric tectonic motion with fine resolution and consistent accuracy (Molnar and Lyon-Caen, 1989; Molnar, 1990). And the quality, distribution and density of observed data are the basis for studying crustal tectonic deformation. In the past, crustal deformation is usually determined indi-r…     

翡翠的矿物组成及其宝石学意义

翡翠的矿物组成是影响翡翠质量及其物理性质的最根本原因,同时玉石质量也受其结构、构造的影响.辉石类矿物是组成翡翠的主要矿物,次要矿物包括有长石族矿物和闪石族矿物,常见的副矿物有铬铁矿、绿泥石、褐铁矿等.矿物组成的复杂性直接导致了翡翠种类、颜色的多样性变化,同时也对透明度、光泽度、比重、硬度及工艺性能等产生影响.所以,翡翠的矿物组成是质量分级评价最根本的依据,具有很重要的宝石学意义.     

衡重式挡土墙土压力的非线性分析

通过对挡土墙土压力非线性分析方法的研究 ,推导出了衡重式挡土墙土压力计算的数解公式 ,并编制了相应的计算程序 ,一般的直线型墙背挡土墙和折线型墙背挡土墙土压力计算均可作为本文计算公式的特例。通过对一折线型墙背重力式挡土墙的土压力计算与实测结果的比较表明 ,由本文公式所得的解与实测结果很接近。     

KL变换消除探地雷达数据中的水平相干噪声

由于探地雷达采用共偏移距剖面的工作方式,造成数据记录中存在大量水平相干噪声。探讨了采用KL变换消除这些水平相干噪声的方法,并给出了具体的实现步骤。最后通过模型试验和实际数据验证了该方法的有效性。     

Sr, Nd and Pb Isotopic Systematics of the Cenozoic Basalts of the Korean Peninsula and Their Implications for the Permo-Triassic Continental Collision Boundary

Sr, Nd and Pb isotopic compositions of the Cenozoic basalts were analyzed from Baengnyeongdo Island, Jeongok, Ganseong, and Jejudo Island of Korea. They reveal relatively enriched Sr and Nd isotopic compositions (⁸⁷Sr/⁸⁶Sr = 0.703300.70555, ¹⁴³Nd/¹⁴⁴Nd = 0.512980.51256) compared with MORB.²⁰⁷Pb/²⁰⁴Pb and ²⁰⁸Pb/²⁰⁴Pb values of all the analyzed Korean basalts lie above the Northern Hemisphere Reference Line (NHRL) defined by Hart (1984). Pb isotopic compositions of basalts from Jejudo Islands (²⁰⁶Pb/²⁰⁴Pb = 18.6119.12, ²⁰⁷Pb/²⁰⁴Pb = 15.5415.69, ²⁰⁸Pb/²⁰⁴Pb = 38.9839.72) are significantly more radiogenic than the rest (²⁰⁶Pb/²⁰⁴Pb = 17.7218.03, ²⁰⁷Pb/²⁰⁴Pb = 15.4415.58, ²⁰⁸Pb/²⁰⁴Pb = 37.7738.64). The Cenozoic Korean basalts thus can be divided into two groups based on their Sr, Nd and Pb isotopic compositions. The north group reveals mixing between DMM and EM1 while the south group displays DMM-EM2 mixing. Such a distribution is the same as Chinese Cenozoic basalts and it can be interpreted that the subcontinental lithospheric mantle under Korea represents simple lateral continuation of the South and North China Blocks. We suggest that Korean continental collision zone cross the Korean Peninsula through the region between the north and south basalt groups of Korea.     

磁测资料处理新方法及在危机矿山挖潜中的应用

研究了危机矿山深部找矿的高精度磁测资料处理解释新方法技术:基于三度体数值积分法的三维可视化精细反演, 小波分析方法提取深部弱磁信号,起伏地形下高精度磁测资料快速化平处理的等效偶层法,以及旧资料 换算为 并与新资料对比的综合处理解释等方法。将这些新方法运用于大冶铁矿危机矿山的深部找矿,获得明显的地质效果。2005年根据解释结果在15线布置的钻孔打到了26.65 m厚的磁铁矿体,说明在危机矿山进一步挖潜中,新方法技术的运用是十分必要的。     

苏里格气田盒8气藏的砂体展布特征

受到地震分辨率的限制,河流相薄而窄的砂体展布很难预测。根据苏里格气田的实际情况,在地震保幅处理、水平井地质录井、修正等时试井等资料的基础上,运用单砂体模式识别技术确定砂体展布,并建立了苏里格气田盒8气藏砂体分布的地质模型。通过研究对比运用多种技术方法综合确定河流相薄而窄小的砂体是切实可行的,所建立的砂体分布地质模型为开发井位优选提供了依据。     

非饱和黄土渗透性的试验研究

通过对甘肃陇西地区的湿陷性黄土做现场浸水试验和室内渗透试验、粒度分析试验，得到了陇西黄土的渗透系数（K20）随孔隙比（e）和吸力（s）的变化规律，为研究黄土浸水入渗规律，求解湿陷性黄土非稳态渗流方程做了必要的准备。