二连盆地白音查干凹陷下白垩统腾格尔组沉积相   总被引：3，自引：1，他引：2  

岳信东  林春明  李艳丽  徐深谋  张志萍  漆滨汶  王秀林  张放东 《沉积学报》2008,26(4):593-601

根据岩心、电测曲线、录井、分析化验、地震等资料,研究了白音查干凹陷下白垩统腾格尔组沉积相类型和沉积特征,以及腾格尔组沉积相分布规律。结果表明,腾格尔组发育扇三角洲、辫状河三角洲、湖泊和浊积扇4种沉积相,扇三角洲分布在北部陡坡,辫状河三角洲分布南部缓坡,从盆地边缘到盆地中心,沉积相由扇三角洲、辫状河三角洲沉积渐变为半深湖—深湖相沉积,在三角洲侧翼发育滨—浅湖相沉积,在三角洲前缘以及前三角洲和半深湖中发育浊积扇,整体呈南北分异、东西分化,这种沉积格局受盆地周边断层和古地形控制。扇三角洲和辫状河三角洲前缘亚相带仍然是油气聚集的重要相带,而与断层相关的其前缘近岸浊积扇是岩性油气藏勘探的有利目标。  相似文献   

鄂尔多斯盆地东部山西组海相沉积环境分析   总被引：14，自引：1，他引：13  

叶黎明  齐天俊  彭海燕 《沉积学报》2008,26(2):202-210

以地球化学指标为主,结合地层古生物和原生沉积构造等各方面的证据,进一步分析了鄂尔多斯盆地东部山西组的沉积环境。泥岩样品的地球化学特征表明,由于受潮汐和海侵作用的影响,整个山西期盆地东部的沉积水体以混合水为主,其中硼元素反映了基准面长期旋回的变化特征,而Sr/Ba则是超长期的变化指标;从沉积构造和海相化石分布特征可知,在山西早期中等强度的潮汐作用直接影响了研究区的东南部,对三角洲沉积进行改造,到了山西中晚期三角洲进积作用增强,潮汐作用范围逐渐退至研究区东南缘;此外,地层的分布特点和沉积相也说明在整个山西期盆地东部地层和晋西地层联片沉积且属于同一三角洲沉积体系,东部的水下隆起还不足以阻隔水体形成湖盆,所以鄂尔多斯盆地东部山西组是发育在浅海陆棚基础上的三角洲沉积。  相似文献   

长江河口水下三角洲¹³⁷Cs地球化学分布特征   总被引：10，自引：8，他引：2       下载免费PDF全文

张瑞  潘少明  汪亚平  高建华 《第四纪研究》2008,28(4):629-639

文章通过对长江口水下三角洲采集的10个柱状样放射性核素¹³⁷Cs的分析可以得知,长江口水下三角洲¹³⁷Cs剖面中均存在清晰的最大蓄积峰,其峰值比活度介于5.68±1.03～21.74±1.39Bq/kg之间,平均值为14.11±1.10Bq/kg,最大蓄积峰所处的深度为55～117cm。剖面中¹³⁷Cs最大蓄积峰应该与1963年的¹³⁷Cs散落沉降相对应。长江口水下三角洲的表层沉积物中的¹³⁷Cs比活度范围介于0～9.19±1.12Bq/kg之间,并且与长江流域其他地区的表层¹³⁷Cs比活度相一致。长江口水下三角洲可探测到的¹³⁷Cs比活度的最大深度范围在88～160cm的范围内变化,¹³⁷Cs蓄积总量为2361.30±174.38～17714.94±262.14Bq/m²,平均值为9664.97±100.05Bq/m²,¹³⁷Cs比活度的最大深度及¹³⁷Cs蓄积总量均表现出从岸向海逐渐增加的趋势。实测的¹³⁷Cs总量均大于长江流域的¹³⁷Cs背景值,说明了长江口水下三角洲的¹³⁷Cs蓄积既有大气散落直接沉降的来源,又有流域侵蚀带来的¹³⁷Cs输入,并且主要以后者为主。通过放射性核素示踪模型分析长江口水下三角洲¹³⁷Cs散落蓄积特征可以得知,长江口水下三角洲¹³⁷Cs的蓄积以长江流域来源为主,说明了放射性核素¹³⁷Cs在长江口水下三角洲沉积物中的蓄积主要受流域侵蚀因素的影响。  相似文献   

Assessing the recent (1834 – 2002) morphological evolution of a rapidly prograding delta within a GIS framework: Macquarie Rivulet delta,Lake Illawarra,New South Wales     

C. A. Hopley  B. G. Jones  M. Puotinen 《Australian Journal of Earth Sciences》2013,60(8):1047-1056

The recent morphological evolution of Macquarie Rivulet delta, Lake Illawarra, New South Wales, has been assessed from historical parish maps from 1834, 1892, 1916 and 1927 along with aerial photographs from 1938 to 2002. These images were digitised, georeferenced and analysed in a GIS framework. The 1834 sketch map could not be georeferenced and it was excluded from the calculation of delta progradation areas. Between 1892 and 1927 morphological changes were minimal, probably because the areas were not resurveyed between these map editions. A significant change in morphology between 1927 and 1938 reflects a change in source material from maps to aerial photographs. The research highlights that great care must be taken when utilising historical data. Major morphological changes observed between 1938 and 2002 included the development of a large crevasse splay in the 1960s to 1970s and the abandonment and infilling of the delta's previously active distributary channels. The research shows that the morphological changes observed on the delta can be related to both natural processes and anthropogenic modifications to the catchment and thus could be used in the development of catchment management plans.  相似文献   

Detecting coastline change from satellite images based on beach slope estimation in a tidal flat     

《International Journal of Applied Earth Observation and Geoinformation》2013

Beach heights and tidal variation have large impacts on the accuracy of estimates of coastline position and its historical changes of a wider and flatter beach based on remote sensing data. This study presents an approach to analysis of waterline movement based on the beach slope, estimated from two effective images with Landsat images data. Two images acquired at different stages of the tide were processed to delineate accurately the position of the waterline. Then waterlines were assigned heights using elevations predicted by a two-dimensional non-linear tidal assimilation model. Beach slope can be calculated piecewise using the heighted shorelines based on the equiangular triangle theory. The positions of the national tidal height datum coastline can be obtained by the beach slope calculation method to accurately monitor the changing of coastline. A change in the coastline of the southwest tidal flat of the Yellow River delta, from Tianshuigou to the Xiaoqing River mouth, was detected by combining field measurements of profiles and bathymetric data. The root mean squared error (RMSE) of the calculated slope of the intertidal zone was one order of magnitude less than the measured slope. The minimum error of self-consistency check is 0.2%. The RMSE between the coastlines estimated by the proposed method and those surveyed data varies from 53.98 m to 217.72 m. It is shown that this method is more suitable for the two years and over the time scales of shoreline change monitoring. To assess erosion/accretion patterns in the tidal flat, and the controlling factors, the volume of the beach was investigated as a possible indicator. The accepted coastline position and changes in the beach volume were used to monitor the changing pattern of accretion and erosion along the coast southwest of the recent Yellow River mouth.  相似文献   

Late Quaternary depositional history of the Reuss delta,Switzerland: constraints from high‐resolution seismic reflection and georadar surveys     

Frank O. Nitsche  Alan G. Green  Heinrich Horstmeyer  Frank Büker 《第四纪科学杂志》2002,17(2):131-143

Glacial erosion has caused overdeepening of many alpine valleys. After retreat of the ice, they were filled with heterogeneous deposits of glacial, lacustrine and fluvial sediments. A typical example of such a valley segment and its infill is the Reuss delta on the southern shore of Lake Lucerne in Switzerland. To obtain a detailed three‐dimensional image of this valley segment, the ETH Institute of Geophysics has acquired several two‐dimensional, high‐resolution seismic and georadar profiles, and conducted a three‐dimensional georadar survey. Interpretations of these geophysical data were constrained by a geological core extracted from a borehole 300 m deep near the investigation site. The seismic profiles imaged ca. 600 m of sediment infill above bedrock. Based on their reflection characteristics, five different deposition units were distinguished. These units were interpreted as a succession of clay/silt at the base, followed by different sand units with variable but generally increasing amounts of gravel. This succession represented a prograding delta that filled the southern part of Lake Lucerne. The latest fluvial development of the region is best represented by the georadar data. In particular, the three‐dimensional georadar data set provides a detailed view of an ancient braided river channel Copyright © 2002 John Wiley & Sons, Ltd.  相似文献   

长江三角洲ZK01孔末次盛冰期以来沉积物粒度特征及环境演化          下载免费PDF全文

邓程文  张霞  林春明  徐振宇  于进 《沉积与特提斯地质》2016,36(3):37-46

根据长江三角洲ZK01孔的粒度资料,从粒度参数、斜体图、概率累积曲线和频率分布曲线等对末次盛冰期以来的沉积物粒度特征进行了详细分析,并结合沉积物的岩性、沉积构造和有孔虫的分布特点,探讨了该区末次盛冰期以来的沉积环境演化。分析表明,ZK01孔末次盛冰期以来,沉积物自下而上可分为5段:河床沉积物以砂和砾质砂为主,粒度概率累积曲线为以跳跃总体为主的两段式;河漫滩相为砂质和黏土互层,概率累积曲线呈以悬浮总体为主的具过渡的两段式,频率分布曲线为双峰或多峰式;河口湾沉积物的粒度参数变化显著,在C-M图上表现为粗细分异明显的两类,对应两种两段式累积曲线,频率分布曲线亦有单峰和双峰式两类;浅海相主要为淤泥质黏土,粒度参数较稳定,概率累积曲线为一段式,几乎均为悬浮总体;三角洲沉积物以细砂和粉砂为主,概率累积曲线为以跳跃总体为主的具过渡的两段式。研究区该时期依次经历了河床、河漫滩、河口湾、浅海和三角洲等5种沉积环境。  相似文献   

塔里木盆地S1井区志留系柯坪塔格组下沥青砂岩段沉积相新认识          下载免费PDF全文

尚凯  郭娜  张睿 《沉积与特提斯地质》2016,36(4):14-20

在岩心观察的基础上,通过对岩石学特征、粒度、沉积构造、微量元素、测井和地震等资料的综合分析,对塔里木盆地S1井区志留系柯坪塔格组下沥青砂岩段沉积相进行了研究。认为本区该套地层主要发育受潮汐影响的辫状河三角洲前缘亚相。进一步可识别出水下分流河道、支流间湾、河口砂坝等沉积微相。结合地震属性资料,分析了研究区沉积相平面分布特征。水下分流河道微相砂体储集物性最好,河道的多期迁移、纵横向叠置形成了大面积分布的良好储集体。  相似文献   

新疆巴尔鲁克山一带下—中泥盆统库鲁木迪组岩相剖面分析及相模式建立     

刘松柏  王小刚  张文峰  刘林波  温志刚  彭志军 《地质通报》2016,35(9):1427-1440

新疆西准噶尔巴尔鲁克山一带下—中泥盆统库鲁木迪组曾被广泛认为是滨海-浅海沉积相。通过测制库鲁木迪组Ⅰ、Ⅱ岩相剖面,结合工作区内库鲁木迪组岩性、沉积构造、厚度、化石等特征,研究其沉积岩石学及相特征,划分沉积相单元、组合序列,分析其由冲积扇、扇三角洲及滨-浅海相组成,重点建立该区早—中泥盆世沉积模式,为后期区域地质矿产调查工作提供一定的基础地质资料。  相似文献   

长三角部分地区土壤中22种有机氯农药的分布特征   总被引：1，自引：1，他引：0  

时磊  孙艳艳  吕爱娟  蔡小虎  沈小明  沈加林 《岩矿测试》2016,35(1):75-81

针对长三角地区长期工业化对农业生态环境构成较大风险,本文利用气相色谱法对该地区不同利用类型土壤中22种有机氯农药进行测定,研究了有机氯农药的残留状况及其在4条土壤垂向剖面中的分布特征。结果表明,不同利用类型表层土壤中有机氯农药残留平均值为工业园区菜地(139.87 ng/g)工业园区荒地(103.1 ng/g)农业区传统菜地(26.27 ng/g)农业区水稻田(2.50 ng/g)。表层土壤中DDTs和HCHs是主要污染物,DDTs含量为0.14~485.73 ng/g(均值44.43 ng/g),HCHs含量为0.69~66.69 ng/g(均值7.73 ng/g),(DDD+DDE)/DDTs值表明该地区近期外源DDTs输入较少。土壤剖面样品分析表明,DDTs和HCHs的含量均随土壤深度增加而迅速降低,这与剖面土壤包气带岩性均以黏土和亚黏土为主,削弱了地表径流对有机氯农药的垂直迁移动力有关。本研究可为控制和改善该地区污染状况提供相关数据。  相似文献