山西交城水峪贯区域构造及地貌形成因素分析     

何晓东 《吉林地质》2013,(4):23-26

交城水峪贯区域地质构造复杂,三大岩类齐全,岩浆岩类发育,岩层露头特征明显,并伴有煤、铁等矿产分布。区内主要发育NNW、NNE、SN向构造体系,从构造、地貌、地层及岩浆岩等因素分析,本区域经历了多次地质构造运动,对其影响最大的为燕山运动。在早燕山期构造运动中近EW向的主应力作用下形成了本区域古洞道向斜、鲁沿向斜、山前大断裂等构造及狐偃山六大岩浆岩体,后期受应力转变造成本区域X型剪节理发育及构造扭曲等现象。形成了本区域现代地质构造及地貌轮廓。  相似文献   

黄土塬竖井剖面黄土-古土壤碳同位素记录特征   总被引：5，自引：1，他引：4  

张普  刘卫国  周卫健  武振坤  宋少华 《地球化学》2008,37(5)

选取位于黄土高原中部西峰和洛川塬面中心地区,分别开挖一个竖井获得L2以来连续黄土-古土壤沉积序列的剖面,并对剖面样品的总有机碳、无机碳酸盐的碳同位素组成进行分析.结果显示黄土-古土壤的有机质碳同位素变化与前人对天然剖面的研究结果一致,同时也注意到黄土-古土壤序列有机碳δ813Corg与无机碳酸盐δ13Ccarb有相似的变化趋势,两者在统计学分析意义上均呈显著正相关关系,西峰塬和洛川塬的相关系数分别为r=0.615和r=0.314,a<0.01,该结果与以往对黄土高原塬面边缘天然露头剖面获得有机碳与总碳酸盐碳同位素呈反相关趋势的结论不一致.对于这种现象的初步解释可能是:(1)来自后期的改造作用:由于黄土沟谷出露的天然剖面多发生在雨水冲刷黄土塬面所切割形成的沟谷两侧,这样天然剖面处于一个开放或半开放的环境,其表层至某一深度受外界水热环境和气体交换影响黄土中的无机碳酸盐;(2)同时黄土-古土壤竖井剖面也可能受土壤CO2分压的影响造成土壤次生碳酸盐的形成而导致同位素变化趋势的复杂性;(3)采样点区域性的差异.结果表明,深入研究不同地区塬面竖井剖面黄土-古土壤碳同位素组成并与相应地区的天然剖面碳同位素组成进行对比,将有助于更准确地理解黄土-古土壤碳同位素所记录的古植被和古气候变化历史.  相似文献   

砂质辫状河储层构型表征及其对剩余油的控制--以渤海海域P油田为例     

徐中波  申春生  陈玉琨  康凯  罗宪波  何新容  李林  张博文 《沉积学报》2016,34(2):375-385

砂质辫状河内部不同级次的构型模式,特别是心滩坝及其内部夹层的构型特征尤为重要,直接控制了油田开发中后期剩余油富集与分布。采取现代地质调查与地下地质解剖相结合的思路,以渤海海域P油田为例,分别从辫流带、心滩坝及心滩坝内部夹层三个级次,探讨了砂质辫状河构型特征及其对剩余油分布规律的影响。结果表明砂质辫状河道具有三种充填样式,且以砂质充填为主,心滩坝与辫状河道呈"宽坝窄河道"的分布样式;坝内落淤层具有穹窿式和水平式两种分布样式。此外,从5级至3级构型单元逐步细分,通过三种识别标志划分单一辫流带,平均宽厚比约178;心滩坝辫状河道宽度与心滩坝宽度比约为1:3.8,心滩坝宽度与长度比约为1:2.2;心滩坝内部单期落淤层近水平分布,多期之间互相平行,一般2~4个。不同级次储层构型要素对剩余油分布的控制存在差异性。对于辫流带级次,层间隔层直接控制剩余油分布;心滩坝级次泥质半充填河道底部砂体连通,侧翼上部水淹程度较低,剩余油富集;受落淤层和物性界面的影响,心滩坝内部剩余油主要呈"分段式"富集在落淤层下方垂积体的顶部和水驱较弱的边部。该成果在油田老区综合调整方案和新区开发方案设计上得到了应用,也在调整井部署,尤其是水平井挖潜剩余油等方面,提供了地质依据。  相似文献   

塔里木盆地北缘阿克苏地区震旦系露头层序地层研究   总被引：2，自引：0，他引：2       下载免费PDF全文

康建威  牟传龙  周恳恳  王启宇  陈小炜  梁薇  葛祥英 《沉积与特提斯地质》2016,36(2):47-54

本文对塔里木盆地北缘阿克苏地区磷矿沟震旦系剖面进行了详细的沉积体系研究。结果表明,该剖面主要发育滨岸沉积体系、碎屑岩潮坪沉积体系和碳酸盐潮坪沉积体系,这几种沉积体系的组合反映了震旦纪阿克苏地区由碎屑岩体系向碳酸盐岩体系的演化过程。在野外露头中共识别出4种不同类型的层序界面:(1)海侵上超层序不整合界面;(2)水进侵蚀冲刷面;(3)岩性、岩相转换面;(4)暴露溶蚀面。在识别出层序界面的基础上对震旦系划分出2个二级层序和5个三级层序。第一超层序SS1包含3个三级层序:SQ1、SQ2和SQ3。第二超层序SS2包含2个三级层序组:SQ4和SQ5。  相似文献   

Sea state characterisation of the test site of an offshore wave energy plant     

Joo M.B.P. Cruz  Antnio J.N.A. Sarmento 《Ocean Engineering》2007,34(5-6):763-775

The Archimedes Wave Swing (AWS) pilot plant, rated at 2 MW, was tested offshore at Póvoa de Varzim in northern Portugal in 2004, gathering a large team of engineers and scientists. The Mechanical Engineering Department of Instituto Superior Técnico was involved, following previous work done for the project. The present paper describes one of the studies conducted. It aims to characterise the sea state at the actual location of the pilot plant using the available pressure sensors. Two approaches were performed: a first one purely based in linear wave theory, neglecting the presence of the device, and a second one, based on the results from a Boundary Element Method (BEM) code named AQUADYN, originally developed at École Centrale de Nantes (France), which allowed a detailed quantification of the effects of the presence of the plant on the wave profile directly above it. Comparisons with a Datawell Waverider buoy located at a certain distance from the plant also played an important role in the current study.  相似文献   

Imaging spectroscopy as a tool to study sediment characteristics on a tidal sandbank in the Westerschelde     

B. Deronde  P. Kempeneers  R.M. Forster 《Estuarine, Coastal and Shelf Science》2006,69(3-4):580

This paper focuses on the use of imaging spectroscopy for the mapping of sediment characteristics on a tidal sandbank in the Westerschelde, called the Molenplaat. On June 8, 2004, during low tide, a HyMap™ scanner recorded the Molenplaat at 4 m pixel resolution. The hyperspectral data were radiometrically calibrated, geometrically corrected, and atmospherically corrected to give apparent surface reflectance data. On the calibrated and corrected dataset a supervised binary classification was performed, based on linear discriminant analysis. Simultaneous to the flight, 25 sediment samples were collected in the field and analysed in the lab to define the median grain size, the water content, the total organic matter content and the chlorophyll-a concentration. These four parameters play a crucial role in sediment stability and macrofaunal habitat definition. Prior to the classification, a feature selection, based on sequential floating forward search (SFFS), was performed. For each of the four parameters two to three bands were retained for the classification. These bands were most frequently selected in the visible and near infrared parts of the spectrum, except for the organic matter content where also SWIR bands were used. The overall classification accuracy was highest for the water content (88%), the median grain size (88%) and the chlorophyll-a concentration (84%). The organic matter content, for which three instead of two classes were distinguished, scored somewhat lower but still reached 80%. The classifications were limited to a small number of classes in order to obtain reliable statistics with a small number of training samples. The spatial patterns in the classified images indicated that the four parameters under study are highly correlated. In most cases coarse sediment coincided with dry conditions, low organic matter and low concentrations of chlorophyll-a. The wet and muddy parts of the Molenplaat were in general characterised by a notably higher amount of organic matter and chlorophyll-a. The individual classification results for the median grain size, the water content and the chlorophyll-a concentration were combined to generate a sediment ecotope map. The presented study illustrates how airborne hyperspectral data can be used to achieve accurate classified maps of intertidal sediment ecotope types, applying feature selection and a binary classification approach.  相似文献   

含煤建造露头层序地层分析—以太原西山石炭二叠系剖面为例   总被引：4，自引：3，他引：4  

陈世悦  刘焕杰 《煤田地质与勘探》1995,23(2):13-17

从太原西山石炭二叠系标准剖面入手，探讨了露头层序地层分析方法，含煤地层格架研究中的应用。太原西山石炭二叠纪沉积建造可分为２个陆表海碳酸盐岩与硅质碎屑岩混合沉积层序和２个河流碎屑岩层沉积层序，其形成受控于３级海平面变化。  相似文献   

Microbial ecology and geochemistry of soils containing iron pans     

C.?R.?AndersonEmail author  I.?M.?Turnbull  M.?R.?Rosen 《Environmental Geology》2003,45(2):209-220

Soils in New Zealand, and elsewhere, often contain substantial zones of ferro-manganese concretions and pans (laterally continuous layers) that can affect soil quality and management. Soils containing concretions and pans from Southland, New Zealand, were investigated to determine links between microbial ecology and geochemistry. Three soil profiles were sampled at 100-mm intervals to a depth of 1 m and then assayed for nine different populations of bacteria using selective media. Geochemical analysis was performed on the soils at the same intervals, and on shallow groundwater from nearby wells. The largest concentrations of iron (Fe) and manganese (Mn) coincide with concretions. Nitrogen (N) and carbon (C) are not correlated with Fe and Mn but may be depleted due to bacterial metabolism. Fe and Mn concentrations in groundwater are low, suggesting that the source of these elements in the concretions and pans is in situ weathering rather than groundwater. Numbers of iron oxidising organisms increase where concretions and pans are encountered, but manganese-oxidising organisms decrease. Heterotrophic, sulphur-oxidising, and anaerobic populations have relatively consistent numbers at all depths within the profiles. Fifty organisms were selected for phylogenetic characterisation, of which only Pseudomonas sp. is known to have significant interactions with Fe and Mn. These results suggest a link between concretion development and iron-oxidising microbial populations.  相似文献   

Observation and analysis of frequency-dependent anisotropy from a multicomponent VSP at Bluebell-Altamont field, Utah   总被引：1，自引：0，他引：1  

E. Liu  J. H. Queen  X. Y. Li  M. Chapman  S. Maultzsch  H. B. Lynn  E. M. Chesnokov   《Journal of Applied Geophysics》2003,54(3-4):319

In this paper, we present results from the analysis of a multicomponent VSP from a fractured gas reservoir in the Bluebell-Altamont Field, Utah. Our analysis is focused on frequency-dependent anisotropy. The four-component shear-wave data are first band-pass filtered into different frequency bands and then rotated to the natural coordinates so that the fast and slow shear-waves are effectively separated. We find that the polarisations of the fast shear-waves are almost constant over the whole depth interval, and show no apparent variation with frequency. In contrast, the time delays between the split shear-waves decrease as the frequency increases. A linear regression is then applied to fit the time-delay variations in the target and we find that the gradients of linear fits to time delays show a decrease as frequency increases. Finally, we apply a time-frequency analysis method based on the wavelet transform with a Morlet wavelet to the data. The variation of shear-wave time delays with frequency is highlighted in the time-delay and frequency spectra. We also discuss two mechanisms giving rise to dispersion and frequency-dependent anisotropy, which are likely to explain the observation. These are scattering of seismic waves by preferentially aligned inhomogeneneities, such as fractures or fine layers, and fluid flow in porous rocks with micro-cracks and macro-fractures.  相似文献   

深水浊积岩层序地层学研究中碳氧同位素的应用——以湖南大庸田坪剖面为例   总被引：1，自引：0，他引：1       下载免费PDF全文

陈明  万方  蒲心纯 《沉积与特提斯地质》2002,22(4):55-60

笔者通过海平面变化曲线与碳氧同位素曲线比较，发现两者曲线基本吻合，碳同位素曲线显示的海平面变化更接近露头层序地层的海平面变化；氧同位素曲线与露头层序海平面变化大体一致。局部出现相反结论。碳同位素曲线对沉积环境变化较氧同位素曲线更敏感。通过两者曲线研究，说明运用稳定同位素曲线变化可作为浊积岩层序地层学研究的一个研究手段。  相似文献