基于GIS对钙质结核土微观结构定量分析研究

文章研究通过运用地理信息系统(GIS)及数字图像处理技术对安徽平原的钙质结核土进行图像分析、处理,进而提取钙质结核土的各种定量参数,如钙质结核的形状、大小,钙质结核的周长和面积等一些相关指标。探索基于GIS数据图像处理技术在钙质结核土分析研究中的可行性和有效性方法;进而为获得安徽淮北平原地区钙质结核土的微观参数以及对钙质结核土的各物理力学指标的变化规律的研究提供新途径和快捷的方法。     

钙质结核土缩尺试验压缩系数修正方法研究

为了研究钙质结核土缩尺试样的压缩特性及其参数的修正方法,本文提出适用于钙质结核土的缩尺方法,并对比分析不同钙质结核质量分数的钙质结核土大型压缩试验和缩尺试验下的压缩性,对缩尺试样的压缩系数进行修正.结果表明:对钙质结核土使用相似级配法混合等质量替代法进行缩尺,可以获得适用于常规试验仪器的钙质结核土试样;在相同的钙质结核...     

淮北平原钙质结核土与高氟地下水成因关系分析

淮北平原第四系地下水丰富,是区域内主要的生活、生产水资源之一。淮北平原土壤类型主要是钙质结核土和黄泛冲积物形成的新近沉积粉土,土壤母质均富含碳酸钙和氟。文章研究了钙质结核土及高氟水的区域分布;在分别探讨钙质结核土和高氟地下水成因的基础上,从土层性质、气候、水文地质等方面探讨了两者在形成过程中的关系;分析了F-与K+、Na+、Ca2+的相关关系,从而探讨了钙质结核土对高氟地下水形成的促进作用。     

非风成陆相土状堆积层中垂直节理和钙质结核的粗浅分析

一、前言较长时间来,一些文献把陆相土堆积层的垂直节理和钙质结核。看作是干早—半干旱气候区风力堆积层的特证,例如成都粘土,曾有一些文献主要依据其含有钙质结核事实,论述其属风力沉积。产生这个错觉的原因之一,是风成黄土垂直节理和钙质结核,发育良好,分布普遍,广为地质、地理学者所知,而非风成陆相土状堆积层内的垂直节理和钙质结核,未闻有过报导。另外,普通地质学、动力地质学、第四纪地质学和地貌学等教材,对风成黄土所具有的垂     

淮北平原钙质结核土的结构类型和成因分析

钙质结核土是淮北平原常见的区域性特殊土,有着独特的形成机理和分布规律。文章通过地质调查、勘察和室内外试验资料的综合分析,并参阅工程地质勘察报告和专业文献资料,对淮北平原钙质结核土的结构类型进行了研究,分析了区内钙质结核土在水平区域分布和垂直分布上的特点;结合成土原理、矿物结晶学和微观组织热力学,分析了钙质结核的形成原理,得出钙质结核土是成土作用和成岩作用共同参与的结果;同时分析了不同成因方式带来的钙质结核土结构和分布上的差异。所得结果对于研究钙质结核土的工程性质具有重要意义。     

柴北缘N1井储层的源控成岩演化与钙质夹层成因

以柴达木盆地北缘N1井为例,通过镜下观察和地化分析,探讨埋藏成岩阶段一类钙质夹层的形成过程。结果表明:N1井储层中的钙质夹层被两期烃源岩热降解成因方解石胶结(Ca1,Ca2),含少量沥青浸染高岭石;相邻高孔渗层溶蚀作用强烈,可见残余方解石、高岭石和两期沥青(Hy1,Hy2);钙质夹层非方解石直接沉淀而成,而是在烃源岩两期生排烃控制下储层成岩演化(高岭石—Hy1—Ca1—溶蚀、高岭石—Hy2—Ca2)的结果,即早期溶蚀成因Ca1型和晚期Ca2型钙质夹层的叠加。     

钙质结核土及其大型直剪试验研究

淮北平原钙质结核土是一种区域性特殊土,其工程地质性质领域的研究基本处于空白状态。其力学特性研究的开展,受到钙质结核的限制,传统小型试样的室内试验制样困难,甚至根本无法开展试验。文章采取和制作了多组钙质结核土原状和重塑土样,进行了大型直接剪切试验;分析了原状钙质结核土的级配特征,获得了原状土样的强度指标,并根据重塑土样的试验研究了土体c、φ值之间的变化关系。     

井研-犍为地区麦地坪组-筇竹寺组沉积相特征

井研—犍为地区麦地坪组—筇竹寺组是四川盆地下寒武统页岩气勘探的重要阵地,但沉积特征研究相对薄弱。通过岩心描述和测井资料分析对研究区麦地坪—筇竹寺组进行沉积相特征分析及总结。麦地坪组发育深灰—灰黑色磷质细晶白云岩、灰黑色—黑色含粉砂质页岩与硅质磷块岩互层,硅质结核及水平层理发育,顶部见灰色—深灰色岩屑石英粉砂岩与灰黑色粉砂质泥岩互层,泥岩与粉砂岩突变接触,发育冲刷面、包卷层理、泄水构造以及粉砂岩中的泥粒定向排列,为典型重力流沉积;筇竹寺组发育灰黑色—深灰色页岩、粉砂质页岩与灰色—深灰色钙质细粒岩屑砂岩、灰质粉砂岩、泥质粉砂岩不等厚互层,块状及水平层理,顶部见波状层理和小型交错层理,黄铁矿发育,三叶虫和高肌虫化石发育。建立了2个三叶虫化石带:尖头遵义盘虫(Tsunyidiscus acutus)—阎家寨遵义盘虫(Tsunyidiscus yanjiazhaiensis)带和始莱得利基虫(Eoredlichia)—武定虫属(Wutingaspis)带,以及3个高肌虫化石带:梁山虫(Liangshanella)—小遵义虫(Tsunyiella)化石带、峨眉虫(Emeiella)—粗脊昆明虫[Kunmingella(Validocostatella)fusulus]化石带和朵氏昆明虫(Kunmingella douville)—卵形川滇虫[Chuandianella ovata(Lee)]—简单虫(Mononotella)化石带。研究区受兴凯地裂运动控制,位于坳拉槽西侧缓坡带中,为陆棚相沉积。识别出浅水陆棚、深水陆棚和坳拉槽3个亚相,以及滩坝、砂泥质浅水陆棚、浊积砂、砂泥质深水陆棚、泥质深水陆棚和坳拉槽底共计6个沉积微相。麦地坪组主要发育构造作用下的深水沉积,其顶部发育重力流沉积,富含磷元素,含少量黄铁矿;筇竹寺组发育较稳定构造背景下的陆棚沉积,具有以泥岩沉积为主,磷元素含量低,局部富含黄铁矿等特征。     

川南地区五峰组—龙马溪组沉积环境演化及其对页岩发育的控制

基于岩心观察、薄片观察、电镜观察、XRF元素扫描以及全岩X-衍射、ICP-MS元素分析、总有机碳含量测试等手段,对川南地区五峰组—龙马溪组页岩岩相类型及其沉积环境演化进行分析,并探讨沉积环境高频演化对岩相的控制作用。将川南地区五峰组—龙马溪组页岩划分为富有机质层状生物硅质页岩、富有机质纹层状(长英质-钙质)粉砂页岩、富有机质(钙质)粉砂页岩、富有机质纹层状钙质页岩、中有机质纹层状(长英质-钙质)粉砂页岩、中有机质块状黏土质页岩6种岩相类型。在岩相识别基础上借助特征元素比值Sr/Ba、U/Th、V/Cr、V/Ni、Ni/Co、Sr/Cu及Mo、Cu、Sr含量变化进行古沉积环境恢复,划分出7个演化阶段。结果表明：五峰组沉积早期气候温暖潮湿、水体较为氧化、盐度较低;五峰组沉积中期水体还原性增强、古生产力提高;五峰组晚期气候干冷,水体较为氧化,经历了赫南特冰期;龙马溪组自下而上古气候经历了暖湿—相对干热—暖湿—相对干热的演化,同时古水体也经历了还原—相对氧化—还原—相对氧化的演化。沉积环境高频演化对页岩岩相发育以及有机质富集具有明显的控制作用,不同岩相有机质含量与海洋古生产力和水体还原性均呈现...     

江苏江阴长山下蜀组钙质结核的初步研究

长山位于江阴县东,北临长江,为一东西向延伸,形似纺锤的山,长约3公里,最宽达1千米,顶高约90米。该山基岩由泥盆系五通组石英砂岩和石英岩组成。上覆下蜀组黄土,从山麓到山脊断断续续分布。山顶一带由于树木、杂草丛生,剖面结构不清,仅粗略看出确棕红,淡黄两层,但未见钙质结核。唯山之西麓的剖面最佳,黄土层内含丰富的钙质结核。     

黄土高原黄土地层分区及其地层结构

黄土地层序列同黄土地貌分区有成因上的联系,不同成因的地貌环境其黄土地层结构不同.依据地貌区划结合黄土地层特征可将黄土高原黄土地层划分为以下四个主要分区:1.梁峁地层区.该区又可分为六盘山以西及以东两个亚区;2.源地层区.又可细分为塬亚区.台塬亚区及山麓塬亚区;3.山间盆地地层区;4.河谷地层区。     

Paleosol evolution and environmental change in the Huang-Huai-Hai Plain, China

Paleosols in the Huang-Huai-Hai Plain occur mainly in the Huaibei, Xuhuai, Yischuhe and Jiaolai areas. They result from 3 sedimentation-soil formation cycles since the Late Pleistocene. Each cycle left calcareous concretions, a dark soil horizon, and a topsoil horizon and/or a stratified soil horizon all derived from loess. This paper examines the composition of the concretions, compares this with that of the enclosing soil horizons, and draws some environmental conclusions. Three types occur: embryonic calcareous concretions, mature calcareous concretions, and calcareous hardpans (petrocalcic horizons). The embryonic concretions formed during the mid-Holocene (6780±130 yr. B.P.), mature calcareous concretions during the late-Pleistocene (weighted average of 31 samples = 15670±370 yr. B.P.), and calcareous hardpans (petrocalcic horizons) from 16 to 40 ka B.P. The calcium carbonate content increases from 412 g/kg in the embryonic concretions, to 551 g/kg in the mature concretions, and to 691 g/kg in the hardpan, whereas contents of SiO_2, Al_2O_3 and TiO_2 decrease accordingly. Spore pollen analysis shows that the late-Pleistocene there was dry and cool, whereas the mid-Holocene was warm and humid and lakes were more extensive than today.     

Discovery of a 1.0 Ma Yellow River terrace and redating of the fourth Yellow River terrace in Lanzhou area

Based on the aeolian loess sequence-stratigraphic division and paleomagnetic datings on terraces, we found that an undiscovered terrace with the age of 1.0 Ma BP lies between the Dunwashan terrace and Wuyishan terrace. This terrace recorded an intensive Yellow River incision event during that period. Results of paleomagnetic dating and optically stimulated luminescence (OSL) dating of the Wuyishan loess section and Zaoshugou loess section on the fourth Yellow River terrace (T4) show that the age of the fourth Yellow River terrace in Lanzhou area is 0.86 Ma BP rather than the previously believed 0.6 Ma BP. This result answers a long-term question in the geomorphology community of whether there exists a 0.8 Ma terrace in Lanzhou area. The discovery of the 1.0 Ma Yellow River terrace and redating of the age of 0.6 Ma terrace in Lanzhou area provide new insights into further research on the evolution of Yellow River.     

Discovery of a 1.0 Ma Yellow River terrace and redating of the fourth Yellow River terrace in Lanzhou area

Based on the aeolian loess sequence-stratigraphic division and paleomagnetic datings on terraces, we found that an undiscovered terrace with the age of 1.0 Ma BP lies between the Dunwashan terrace and Wuyishan terrace. This terrace recorded an intensive Yellow River incision event during that period. Results of paleomagnetic dating and optically stimulated luminescence (OSL) dating of the Wuyishan loess section and Zaoshugou loess section on the fourth Yellow River terrace (T4) show that the age of the fourth Yellow River terrace in Lanzhou area is 0.86 Ma BP rather than the previously believed 0. 6 Ma BP. This result answers a long-term question in the ge-omorphology community of whether there exists a 0. 8 Ma terrace in Lanzhou area. The discovery of the 1. 0 Ma Yellow River terrace and redating of the age of 0.6 Ma terrace in Lanzhou area provide new insights into further research on the evolution of Yellow River.     

辽南地区末次冰期以来的环境变化

本文通过对大连七顶山黄土剖面的光释光(OSL)年代、磁化率、地球化学元素、粒度特征等数据,综合分析辽南地区末次冰期以来的环境变化过程,研究结果显示:相当于黄土高原马兰黄土的堆积形成时代为距今125ka。在末次冰期早期(MIS4-5d),86-113ka,沉积物质量磁化率介于6.97-24.14×10-8m3kg-1之间,平均值为14.699×10-8m3kg-1;颗粒粒径较细(3.89-5.22准);硅铝率平均值6.756;风化淋溶系数0.4-0.73之间;退碱系数均值0.333;镁铝比均值22.901。与末次冰期晚期相比,质量磁化率值较高,化学元素各项指标值较低,明了该阶段辽南整体气候环境较为干冷,但并未达到末次冰期晚期程度。而在末次冰盛期时(22-31ka,MIS2),磁化率平均值为6.974×10-8m3kg-1,明显低于末次冰期早期,粒度均值处于3.47准-4.77准之间,主要以颗粒较粗的细砂、粗粉砂为主,粒度明显变粗,硅铝率平均为6.998;风化淋溶系数均值为0.829,退碱系数值0.66,镁铝比值均值28.725,各参数比较一致地表明该阶段研究区整体处于干冷的气候环境之下,堆积作用较活跃。而在末次冰期中期(MIS3)时,OSL年代31-86ka,该区气候条件以温暖湿润为主,黄土遭到侵蚀。     

论结核学的形成发展及其地质应用

阐述了前苏联地质学中结核分析的内涵和由其发展而成的边缘学科——结核学的形成、发展和理论意义,并以俄罗斯顿涅茨等煤田的石炭系地层剖面为例,运用结核分析方法剖析了剖面中结核的成分、种类、含量、分布等与含煤性的关系,探讨了用结核分析法进行地层划分与对比和进行沉积建造分析的可能性及其意义。     

U-Pb ages of zircon grains reveal a proximal dust source of the Xiashu loess,Lower Yangtze River region,China

Deciphering the eolian sources is critical to understand the paleo-significance of the Quaternary eolian deposits （the Xiashu loess） in the lower reaches of the Yangtze River. Both a local source from the fluvial sediments of the Yangtze River and a distal source from the northern deserts similar to that of the loess on the Chinese Loess Plateau （CLP） have been proposed. Recent researches show great advantages of detrital zircon ages as a source tracer for Asian dust based on the laser ablation U-Pb isotopic dating technique. This work presents the U-Pb ages of zircon grains extracted from the Xiashu loess. The results indicate that the Xiashu loess has a very different age distribution of zircon grains from that of the loess on the CLP as well as the materials in the arid lands of the Asian Interior. Instead, the zircon ages of the Xiashu loess are indistinguishable from the fluvial sediments of the Yangtze River, indicating the dominance of proximal dust source. Proximal source of the Xiashu loess implies that extensive eolian processes might have existed in the currently wet South China, possibly in response to the full glacial conditions after the middle Pleistocene transition of global climate.     

An erosional hiatus in Chinese loess sequences revealed by closely spaced optical dating

1 Introduction Loess deposits in China are the thickest and most extensively distributed in the world. Investigations overthe past around one century have significantly im- proved our understanding of the origin, transportation, deposition and evolution o…     

兴义马岭河峡谷瀑华藻类多样性初步研究

本文对贵州省兴义市马岭河峡谷瀑华藻类的物种多样性进行了初步研究,通过定性分析,共记录138种(含变种和变型),隶属于3门6纲12目21科39属.马岭河峡谷瀑华藻类主要是以蓝藻占绝对优势.     

郑州城市地下空间开发敏感地质因子的分布特征

在对郑州市的工程地质相关资料梳理的基础上,针对研究区工程地质特点,结合地下空间开发利用情况,认为研究区地下空间开发的敏感工程地质因子主要有淤泥质土、液化土、湿陷性黄土、钙核富集层。在地下空间开发过程中,为了研究工程地质敏感因子可能导致的环境地质问题,对淤泥质土、液化土、湿陷性黄土、钙核富集层的分布范围进行精确刻画,为地下空间开发利用提供地质依据。