河北省含铁岩系的地球化学特征   总被引：1，自引：0，他引：1  

宫进忠  楚福录  刘振东 《物探与化探》2006,30(5):393-396

依据河北省区域岩石地球化学调查成果,讨论了区内不同成因类型含铁岩系的地球化学特征。其中重要的沉积变质铁矿地层中Al₂O₃、Ti、P、V、Cr、Ni、Cu、Zn的质量分数和w(Fe₂O₃)/w(FeO)、w(Sr)/w(Ba)、w(La)/w(Y)较高,Rb、Li、Cs、Sc的质量分数及w(K₂O)/w(Na₂O)较低;海相沉积型铁矿地层中强烈富集Sb、Li、B、Hg、Sr和K₂O,同时贫化FeO、Na₂O、CaO、Mn、Rb等元素;主要接触交代型铁矿围岩中CaO、MgO的质量分数较高,SiO₂、Al₂O₃、K₂O、Mn、Ti、P、V、Cr、Zr、Ba、REE的质量分数及w(Fe₂O₃)/w(FeO)较低。这些地球化学特征反映其特定的地质构造环境。  相似文献   

湘南骑田岭地区锡多金属矿的岩石磁学研究     

郭友钊  刘海良  张余芝  李宜运  李磊 《物探与化探》2006,30(6):521-524

湘南地区骑田岭芙蓉矿田存在众多航磁以及地面高精度磁力异常,正确认识磁异常与锡多金属矿异常的对应关系,直接涉及到对矿区找矿前景的评价与找矿工作部署。笔者从岩石磁学参数的统计特征来探讨磁法勘探的应用范围及其应注意的问题。  相似文献   

藏北沉鱼湖-向阳湖一带石坪顶组火山岩特征、形成时代及环境   总被引：1，自引：0，他引：1  

刘荣  吕金刚  吴新忠 《新疆地质》2006,24(2):109-114

沉鱼湖—向阳湖一带的石坪顶组火山岩大地构造位置属巴颜喀拉-可可西里地块和南部的若拉岗日裂谷带,岩石结构类型比较简单,以粗面安山岩为主,粗面岩、玄武粗安岩、粗面英安岩次之,以钾质太平洋型钙碱性系列为主.火山岩轻、重稀土分馏程度均较高,重稀土分馏程度比轻稀土稍低一些,具轻稀土富集,重稀土亏损的特点,时代属中新世.K2O/Na2O>1,说明成矿物质为深部幔源物质混合了壳源物质,属大陆板内造山晚期演化的火山岩类型.  相似文献   

含碎石土壤水分入渗试验研究   总被引：24，自引：6，他引：24       下载免费PDF全文

王慧芳  邵明安 《水科学进展》2006,17(5):604-609

采用一维积水垂直入渗法测定含碎石土壤的入渗过程,分析碎石含量和碎石组成对土壤水分运动影响。对试验数据采用Kostiakov入渗公式拟合,得出反映入渗速率的拟合参数比值与土石比成幂函数关系;采用简略的Philip垂直入渗方程幂级数解拟合湿润峰随时间的变化,拟合精度高,并发现拟合参数与土石比仍成幂函数关系。采用简单相关分析碎石粒径对入渗过程影响,得出粒径2~3 mm碎石与入渗过程成显著的负相关关系,而>25 mm碎石有利于入渗。研究结果可为含碎石土壤的水循环提供重要的基础。  相似文献   

无中导洞施工双连拱隧道的数值模拟分析     

赖金星  谢永利  李宁军 《水文地质工程地质》2006,33(3):68-71

针对双连拱隧道采用三导洞或中导洞超前施工方法施工工序多、临时支护量大的不足,以黄延高速公路羊泉沟隧道为例,提出在Ⅲ类围岩中采用无中导洞超前施工方法.基于弹塑性有限元方法对其施工过程进行分析,获得了施工各阶段围岩的应力、应变状态,以及初期支护和二次衬砌的受力状态.结果表明：在Ⅲ类围岩中连拱隧道采用无中导洞施工方法,围岩和支护结构处于安全状态.分析结果为羊泉沟隧道的顺利贯通提供了有效指导.  相似文献   

CLIMATE CHANGE: LONG-TERM TRENDS AND SHORT-TERM OSCILLATIONS   总被引：2，自引：0，他引：2  

高新全  张欣  钱维宏 《热带气象学报(英文版)》2006,12(2):139-149

Identifying the Northern Hemisphere (NH) temperature reconstruction and instrumental data for the past 1000 years shows that climate change in the last millennium includes long-term trends and various oscillations. Two long-term trends and the quasi-70-year oscillation were detected in the global temperature series for the last 140 years and the NH millennium series. One important feature was emphasized that temperature decreases slowly but it increases rapidly based on the analysis of different series. Benefits can be obtained of climate change from understanding various long-term trends and oscillations. Millennial temperature proxies from the natural climate system and time series of nonlinear model system are used in understanding the natural climate change and recognizing potential benefits by using the method of wavelet transform analysis. The results from numerical modeling show that major oscillations contained in numerical solutions on the interdecadal timescale are consistent with that of natural proxies. It seems that these oscillations in the climate change are not directly linked with the solar radiation as an external forcing. This investigation may conclude that the climate variability at the interdecadal timescale strongly depends on the internal nonlinear effects in the climate system.  相似文献   

基于SVM遥感矿化蚀变信息提取研究   总被引：1，自引：0，他引：1  

傅文杰  洪金益  朱谷昌 《国土资源遥感》2006,(2):16-19,i0002

提出一种基于支持向量机(SVM)遥感数据矿化蚀变信息提取的新方法。该方法首先根据蚀变岩及矿体围岩的实测光谱数据,利用光谱角度制图法(SAM)提取训练样本,应用交叉比对(cross-validation)算法确定最优SVM模型参数,选择径向基(RBF)核函数,训练SVM分类器模型;然后,用训练好的SVM模型进行遥感矿化蚀变信息提取;最后,选择青海芒崖地区的ETM数据进行遥感矿化蚀变信息提取试验。试验结果经野外检查和验证,效果良好。  相似文献   

Archaeoseismology: Methodological issues and procedure     

Fabrizio Galadini  Klaus-G. Hinzen  Stathis Stiros 《Journal of Seismology》2006,10(4):395-414

Archaeoseismic research contributes important data on past earthquakes. A limitation of the usefulness of archaeoseismology is due to the lack of continuous discussion about the methodology. The methodological issues are particularly important because archaeoseismological investigations of past earthquakes make use of a large variety of methods. Typical in situ investigations include: (1) reconstruction of the local archaeological stratigraphy aimed at defining the correct position and chronology of a destruction layer, presumably related to an earthquake; (2) analysis of the deformations potentially due to seismic shaking or secondary earthquake effects, detectable on walls; (3) analysis of the depositional characteristics of the collapsed material; (4) investigations of the local geology and geomorphology to define possible natural cause(s) of the destruction; (5) investigations of the local factors affecting the ground motion amplifications; and (6) estimation of the dynamic excitation, which affected the site under investigation. Subsequently, a ‘territorial’ approach testing evidence of synchronous destruction in a certain region may delineate the extent of the area struck by the earthquake. The most reliable results of an archaeoseismological investigation are obtained by application of modern geoarchaeological practice (archaeological stratigraphy plus geological–geomorphological data), with the addition of a geophysical-engineering quantitative approach and (if available) historical information. This gives a basic dataset necessary to perform quantitative analyses which, in turn, corroborate the archaeoseismic hypothesis. Since archaeoseismological investigations can reveal the possible natural causes of destruction at a site, they contribute to the wider field of environmental archaeology, that seeks to define the history of the relationship between humans and the environment. Finally, through the improvement of the knowledge on the past seismicity, these studies can contribute to the regional estimation of seismic hazard.  相似文献   

再论东天山白山铼钼矿区成岩成矿时代   总被引：9，自引：2，他引：9  

李华芹  陈富文  李锦轶  屈文俊  王登红  吴华  邓刚  梅玉萍 《地质通报》2006,25(8):916-922

东天山白山铼钼矿区的成岩成矿时代尚存在海西期和印支期之争.最新的同位素年代学研究表明,矿区南部斜长花岗斑岩的锆石U-Pb年龄为235～245Ma,矿区东部黑云母斜长花岗岩的锆石SHRIMP U-Pb年龄为239Ma±8Ma,矿石中辉钼矿的Re-Os等时线年龄为229Ma±2Ma.结合笔者已报道的燕山期岩浆侵位与成矿的年代学证据,首次提出白山铼钼矿区具有印支期和燕山期2期成岩成矿作用,早期成岩成矿作用发生于中三叠世,晚期成岩成矿作用发生于早侏罗世.  相似文献   

GasBench-IRMS在碳酸盐岩δ^13C和δ^18O在线连续分析中的应用   总被引：1，自引：0，他引：1  

陶成把立强  李广友杨华敏 《岩矿测试》2006,25(4):334-336

采用GasBench-IRMS气体质谱分析技术，实现了碳酸盐岩中碳氧同位素的在线连续分析。优化了色谱柱温、离子源参数等工作条件，排除了空气中N2O的干扰。结果表明，色谱柱柱温为40℃、65℃时，方法线性范围较宽，结果准确可靠。方法用于碳酸盐岩国家一级标准物质中δ^13C和δ^18O的测定，结果与标准值一致。  相似文献