博格达南缘二叠系古土壤类型及其在层序地层研究中的应用   总被引：3，自引：1，他引：2  

冯乔  杨晚  柳益群 《沉积学报》2008,26(5):725-729

古土壤是在地质时期经成壤作用改造原岩而形成土壤。野外实地详细考察和室内研究表明,博格达南缘二叠系中发育4类古土壤,即有机土壤,发育于土壤剖面的近顶部,属于潮湿古环境的产物;泥质土壤,主要发育于淋滤带和淋滤带底部泥质沉淀带,形成于长期淋滤和比较潮湿的古环境;铁质土壤以富含铁质结核为特征,是长期淋滤和潮湿古环境的标志;钙质土壤以富含钙质结核为特征,是干旱—半干旱古环境的标志。通过古土壤的研究能够精细地划分层序旋回和恢复沉积古环境。  相似文献   

西汉末—北宋黄河三角洲（公元11～1099年）的沉积记录   总被引：2，自引：0，他引：2  

薛春汀  李绍全  周永青 《沉积学报》2008,26(5):804-812

西汉末—北宋黄河三角洲是在很浅的水域发育的。在1855年海岸线内侧数千米处三角洲厚度只有12 m左右。无论是整个三角洲,还是水下三角洲各个组成部分（前三角洲、三角洲前缘）都比现代黄河三角洲相应部分要薄。前三角洲之上在不同地点发育三角洲前缘粉砂或者分流间湾黏土质粉砂。推测这一时期三角洲上多条分流同时活动。三角洲中有孔虫和介形虫属种和数量都与下伏陆架沉积物的有明显差别,且自下而上显示越来越受入海河水影响。与苏北、现代黄河三角洲沉积物中生物丰度的比较可以看出沉积速率的增加,反映这一历史时期黄河入海泥沙增加以及黄土高原侵蚀越来越严重。  相似文献   

The Formation and Distribution of the Marine Hydrocarbon Source Rock in the Tarim Basin, NW China   总被引：8，自引：7，他引：1  

CAI Xiyuan  WANG Yi 《《地质学报》英文版》2008,82(3):509-519

There are significant differences in type and distribution between marine source rock and continental source rock. According to the iithology, the Cambrian-Ordovician source rock in the Tarim basin is divided into two types： the carbonate source rock and the mud source rock. The two sets of source rocks are developed mainly in three sets of formations, Lower-Middle Cambrian carbonate source rock and mud source rock, Lower-Middle Ordovician mud source rock and Upper Ordovician lime mud source rock. The stratigraphic and areal distributions of the source rocks are controlled by the altitude and the sedimentary facies respectively. The mud source rock is developed in slope-semi deep sea environment. The source rock developed in the slope sedimentary environment is related with the anoxic environment and the one developed in semi deep sea has a close relationship with the up-flowing sea water. The carbonate source rock is developed mainly in platform slope of highstand systems tract and it is usually intimately associated with the salt rock. The Lower-Middle Cambrian carbonate source rock is developed mainly in the Bachu, Tazhong, Tangguzibasi and Yingmaili areas. The Lower-Middle Cambrian mud source rock is mainly developed in the areas east of the line of Kunan 1-Tadong 1. The Lower-Middle Ordovician mud source rock is developed mainly in the east slope of the Manjiaer depression. The carbonate source rock of Early Ordovician is developed mainly in the platform slope of highstand systems tract, such as the south margin of Tabei, the north slope of Tazhong, the Bachu area and Keping area.  相似文献   

Distribution of Palygorskite in the Lingtai Profile of Chinese Loess Plateau： Its Paleoclimatic Implications     

XIE Qiaoqin  CHEN Tianhu  CHEN Jun  JI Junfeng  XU Huifang  XU Xiaochun 《《地质学报》英文版》2008,82(5)

Palygorskite is a typical indicator mineral of the arid and strong evaporation environment. Distribution of palygorskite in loess-red clay sequences may act as an important indicator for reconstruction of the paleoenvironment and paleoclimate.In this paper,field emission scanning electron microscope and high-resolution transmission electron microscope observations on the red clay-loess-paleosol of the Renjiapo profile at Lingtai,Gansu Province indicate that palygorskite occurs widely in red clay sequences formed before 3.6 Ma,but no occurrence has been found in eolian sediments since 3.2 Ma.Micromorphological features and microstructure of palygorskite show that it is an autogenic mineral formed during pedogenesis,and transformed from illite-montmorillonite under the pore water action.In the Lingtai profile,the disappearance horizon of palygorskite is consistent with those of increasing magnetic susceptibility,dust flux and depositional rate.The distribution of palygorskite in the profile indicates that the interval of around 3.6 Ma was an important transformation period of the East Asian paleomonsoon,when changes took place in the East Asia paleoclimate pattern,i.e.a high-frequency strong fluctuation alternative evolution of the environment. Therefore,palygorskite is a key indicator mineral of the East Asian paleomonsoon evolution of that time.  相似文献   

基于震荡序列的灰色预测模型在边坡沉降监测中的应用     

王岩  黄张裕  张玉爽  艾合塔木&#;依米尼亚孜  王文利 《测绘工程》2017,26(3)

公路边坡由于施工的影响,监测点时升时降,累计沉降量是震荡序列。本文采用三种模型对累计沉降量进行预测。结果表明GM(1,1)和DGM(1,1)预测曲线并不能反映实测值曲线走势,预测值与实测值的偏离程度较大,预测精度较低。SDGM(1,1)模型无论在与实测值曲线走势、与实测值接近程度还是在残差平方和或者平均相对误差上精度要高于其他两种模型,在P,C值上,SDGM(1,1)模型实现"级"的跳跃,是一个非常理想的预测模型。  相似文献   

Testing spatial heterogeneity in geographically weighted principal components analysis     

Javier Roca-Pardiñas  Tomás R. Cotos-Yáñez  Rubén Pérez-Álvarez 《International journal of geographical information science》2017,31(4):676-693

We propose a method to evaluate the existence of spatial variability in the covariance structure in a geographically weighted principal components analysis (GWPCA). The method, that is extensive to locally weighted principal components analysis, is based on performing a statistical hypothesis test using the eigenvectors of the PCA scores covariance matrix. The application of the method to simulated data shows that it has a greater statistical power than the current statistical test that uses the eigenvalues of the raw data covariance matrix. Finally, the method was applied to a real problem whose objective is to find spatial distribution patterns in a set of soil pollutants. The results show the utility of GWPCA versus PCA.  相似文献   

1970年以来华东地区地震活动主体区的迁移   总被引：3，自引：0，他引：3       下载免费PDF全文

顾方琦  张春芝  张枝榴  陈礼 《地震地质》2001,23(3):475-480

在已有工作基础上，对华东地区1970年以来的地震活动特征从时序演化和空间分布两方面作了分析，发现该地区地震在时序上存在前后两个演化过程相似的活动时段，并在空间分布上有着较好的分区性，地震活动主体区域存在明显的迁移。该研究结果有助于华不地区今后地震趋势分析。  相似文献   

祁连山地震带两次中强地震前的加卸载响应比异常   总被引：1，自引：0，他引：1  

李佐唐  施行觉  何少林  许健生  王振亚  王志高  汤晓昌 《地震研究》2001,24(3):197-201

研究了祁连山地震带两次中强地震前的加卸载响应比异常特征，讨论了基于天然地震序列的样本条件对加卸载响应比计算结果的影响，提出处理序列中4．0级以上地震的新方法。  相似文献   

地理信息系统开发方法的演进   总被引：7，自引：0，他引：7  

吴升  王家耀 《测绘学院学报》2001,(2)

随着计算机科学和软件工程技术的进步 ,GIS软件工程方法在不断地演进 ,越来越适合于GIS的开发。文中介绍和回顾了GIS在自身的发展过程中使用的一些软件工程方法 ,并初步探讨了为GIS项目选用软件开发方法的问题。  相似文献   

滇黔桂地区晚震旦世陡山沱期构造-层序岩相古地理   总被引：2，自引：2，他引：2       下载免费PDF全文

陈明  万方  尹福光 《沉积与特提斯地质》2001,21(1):11-26

层序地层是在一个等时地质年代格架内从三维空间上认识一个有成因联系的沉积组合体，层序内部沉积地质体的性质、叠置关系和沉积相演变与海平面升降周期变化有对应关系。对滇黔桂地区晚震量世陡山沱期层序地层研究，笔者在上扬子浅海区对晋宁王家湾上震量统剖面进行实测，拟建立浅海区基干层序剖面，并把陡山沱组划分为一个2级层序和四个3级层序；在深海区对广西灵川西岭剖面进行实测，拟建立深海地区的基干层序剖面。然后在研究区进行辅助对比剖面的观测，以编制该区二级层序海侵体系域和高水位体系域的构造－层序岩相古地理图，通过这些研究，使人们从另一个角度去揭示和认识谝我在陡山沱期的构造运动、沉积物组合特征与海平面变化的关系，从而更进一步弄清该区的时空演化特征。  相似文献