川滇地区强震分区时间分布规律及在中长期预报中的意义

川滇地区 MS≥ 6.0的地震多聚集成带、成团 ,与构造走向大体一致 .在南北地震带中、南段 ( 98°～ 1 0 5°E,2 1°～ 34°N)可划分成 7个小区 .每个小区历史上都发生过 MS≥ 7.0的强震 . 1 970年以来该区发生的 1 0次 7级以上地震 ,分别出现在 5个小区内 .经研究 ,这 5个小区中强震发生的时间与累积频度间均符合幂函数或指数关系 .通过内符检验 ,表明其对每个小区强震的中长期预报具有一定的意义 .     

中低纬度系统相互作用对山东“99.8”大暴雨的影响

９９０７号热带风暴西北上减弱成低气压之后,从黄海进入山东,分别于８月９日夜间、１１￣１２日与西风带系统相互作用,造成了山东部分地、市出现大暴雨或特大暴雨。大暴雨区位于谪空急流入口区的右侧、台风低压移动方向右侧的东南低空急流与西风带弱冷空气交汇处。     

Spreading rate dependence of the axial topography and gravity of the Mid‐Atlantic ridge between 22°N and 38°N

A method is developed to quantify the relationship between the ridge axial topography and gravity and the spreading rate along the Mid‐Atlantic Ridge between 22 and 38°N. This relationship reflects the variations of slope of the best‐fit line of topography and gravity spectra with the spreading rate of the ridge segments. The slope of the best‐fit line of topography spectrum becomes smaller as the spreading rate increases, indicating that with increasing spreading rate more energy of the ridge axial topography shifts into high‐frequency bands. The spreading rate dependence of the ridge axial topography may be explained by an anomalous thermal structure beneath the ridge. No significant correlation was found between the slope of the best‐fit line of gravity spectrum and the spreading rate in this region. The lack of spreading rate dependence of the ridge axial gravity may be attributable to the isostatic compensation of the spreading center.     

地形图从CAD到MapInfo的转换方法研究

目前大多数现有的地形图都是基于CAD格式绘制、存储的,但是CAD格式在数据分析、管理和处理上受到限制,需要转换成GIS格式。本文对地形图从AutoCAD(.dwg)数据格式转换为MapInfo(mid/mif)GIS数据,从图层组织、数据要素管理和背景图形方面对各种方法进行了分析研究。     

全站仪三角高程测量应用综述

随着全站仪的更新换代,全站仪三角高程的测量精度不断提高,其应用领域在不断地扩大和深化。本文着重对单向观测法、对向观测法、中间设站法等三种三角高程测量观测方法进行论述和精度分析,对主要误差来源进行综述,并对其应用领域进行了总结,得到了一些有益的结论。     

Zircon SHRIMP U‐Pb Dating of the Tourmalinites from Boron‐bearing Series of Borate Deposits in Eastern Liaoning and its Geological Implications

This paper focused on the zircon sensitive high resolution ion micro-probeU-Pb geochronology of the tourmalinites from boron-bearing series of borate deposits in Eastern Liaoning. The zircons commonly have core-rim structures, most cores show oscillatory zoning in cathodoluminescence and plane polarized light images, suggesting a magmatic detrital origin. Ages of the magmatic detrital zircons from the hyalotourmalite samples (N13) and (N14) are 2175?±?5??Ma and 2171?±?9??Ma, respectively. Moreover, metamorphic zircon from the sample (N13) shows an age of 1906?±?4??Ma. Zircon core and rim from the hyalotourmalite sample (N02) record ages of 2171?±?6??Ma and 1889?±?62??Ma, which are explained as indicating the formation and metamorphic ages. Combined with the geological and geochemical studies, it can be concluded that the tourmalinites are formed during sedimentary exhalative mineralizations in the mid-Paleoproterozoic (~2170?Ma) and underwent the metamorphism in the late-Paleoproterozoic (~1900?Ma). The tourmalinites are the products of submarine acid volcanism in the extension rifting phase of the Liaoji Paleoproterozoic Rift, the rock-forming materials of which are derived from the mantle sources with recycling crustal contamination. The emergence of tourmalinites not only indicates the mid-Paleoproterozoic tectonic-magmatic processes, but also provides impetus, heat and material sources for the mineralization of borate deposits in Eastern Liaoning.     

川、滇、黔交界地区密西西比河谷型铅锌矿床与美国同类矿床的对比

我国川、滇、黔交接地区和美国中部地区的密西西比河谷型铅锌矿床的共同特征是：1）含矿岩系都位于一套红色碎屑岩石之上。它们不但为矿床的形成提供了成矿金属，而且由于渗透率较大而为成矿流体的大规模侧向流动提供了通道。2）矿床的形成时间都与造山作用的时间相一致。造山作用所引起的挤压应力，或由于造山带的隆起所引起的盆山间的重力梯度为含矿流体的大规模侧向流动提供了动力，促进了成矿作用的发生。3）矿床的含矿岩系大多含有蒸发岩。蒸发岩的存在为成矿流体的形成提供了矿化剂，或为矿质的沉淀提供了硫。     

中祁连东段东缘韧性剪切带特征

位于祁连造山带东段的白银地区，在1：5万区域地质调查中发现了两条近科平行排列的北北东向韧性剪切带，据几何形态和显微组构特征，该剪切带均属于右行走滑韧性剪切带，是加里东末期祁连造山带与泰岭造山带呈反“S”型拼接的产物，区内在构造－岩浆作用下，造成陆块间的走滑或旋转定位。     

我国中亚热带山地土壤有机质研究

本文研究中亚热带地区湖南连云山、万洋山各垂直地带的A层土壤的有机质某些性质的垂直变化规律.TC、TN、Kos、HA/FA、总酸度、羧基和酚羟基含量均表现为随海拔的增高而增加的趋势,E4/E6的结果则相反.Ca键腐殖质变化不明显,Fe.Al键腐殖质、紧结态腐殖质均随海拔的升高而增加.G0%和G1%含量随海拔的升高而减小,G2%含量随海拔的升高而增加,G1/G2比值表现为基带土壤＞0.5,而山地土壤＜0.5.基带土壤中G2组有机碳在复合体有机碳总量中所占的比例较小,山地土壤中G2组有机碳占的比例却最大,都超过50%.聚类分析表明海拔高度对低海拔和高海拔地带土壤的有机质性质的影响小于中间过渡地带.     

基于可拓工程方法的生态地理区域系统界线划分研究—以中温带半湿润、半干旱

利用可拓工程方法中的物元模型对生态地理区域系统的界线问题进行了研究，通过选取样本和指标对单指标关联函数和多指标综合关联函数进行了定量计算。在此基础上，通过专家集成确定了中国中温带半湿润、半干旱区之间的界线，弥补了单指标和定性划分的不足，有助于中国生态地理区域系统的构建。