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1.
博鳌地区沙坝-泻湖沉积及探地雷达的应用 总被引：10，自引：0，他引：10
通过钻孔资料和探地雷达（GPR）反射剖面，揭示了海南岛东部博螯地区晚更新世以来沙坝-泻湖体系沉积序列和内部反射结构，探地雷达（GPR）给出了有关沙体厚度，岩性特征，潜水面深度，海水侵入范围以及沙体含水性等重要参数，是海岸带环境调查的有效手段。通过和钻孔资料的对比，在玉带滩海岸沙坝上部层序中识别出两套具有区域意义的反射波组，南岗村沙洲浅滩识别出一套反射波组，综合分析表明，博螯地区沙坝-泻湖体系晚更新世以来随海平面的上升经历了基岩侵蚀→河流，河漫滩相→泻湖→海岸沙坝，半封闭泻湖，河口湾的演化过程。 相似文献
2.
Sedimentary successions and internal structure of the coastal barrier-lagoon system of Boao, eastern Hainan Island were studied
through utilizing data from test holes and trenches and ground-penetrating-radar (GPR) profiles. During late Pleistocene,
fluvial and delta plains developed over an unevenly eroded bedrock during low sea level stand, followed by the formation of
littoral and lagoon facies and defined coastal barrier-lagoon-estuary system during the post-glacial uppermost Pleistocene-lower
Holocene eustatic rise of the sea level, and the upper Holocene high stand. GPR results show that Yudaitan, a sandy coastal
bar backed by a low-laying land (shoal) just east of the active lagoon, is a continuous, parallel and slightly-wavy reflectors
indicating homogeneous sandy or sandy gravel sediments, and inclined reflectors partly caused by progradation and accumulation
of beach sand and gravel. Quasi-continuous, hummocky and chaotic reflectors from the shoal of Nangang village correspond to
mixed accumulation of sands and clay. This research indicates the GPR is a non-intrusive, rapid, and economical method for
high-resolution profiling of subsurface sediments in sandy gravelly coast. 相似文献
3.
Sedimentary successions and internal structure of the coastal barrier-lagoon system of Boao, eastern Hainan Island were studied through utilizing data from test holes and trenches and ground-penetrating-radar (GPR) profiles. During late Pleistocene, fluvial and delta plains developed over an unevenly eroded bedrock during low sea level stand, followed by the formation of littoral and lagoon facies and defined coastal barrier-lagoon-estuary system during the post-glacial uppermost Pleistocene-lower Holocene eustatic rise of the sea level, and the upper Holocene high stand. GPR results show that Yudaitan, a sandy coastal bar backed by a low-laying land (shoal) just east of the active lagoon, is a continuous, parallel and slightly-wavy reflectors indicating homogeneous sandy or sandy gravel sediments, and inclined reflectors partly caused by progradation and accumulation of beach sand and gravel. Quasi-continuous, hummocky and chaotic reflectors from the shoal of Nangang village correspond to mixed accumula 相似文献
4.
Sedimentary successions and internal structure of the coastal barrier-lagoon system of Boao, eastern Hainan Island were studied through utilizing data from test holes and trenches and ground-penetrating-radar (GPR) profiles. During late Pleistocene, fluvial and delta plains developed over an unevenly eroded bedrock during low sea level stand, followed by the formation of littoral and lagoon facies and defined coastal barrier-lagoon-estuary system during the post-glacial uppermost Pleistocene-lower Holocene eustatic rise of the sea level, and the upper Holocene high stand. GPR results show that Yudaitan, a sandy coastal bar backed by a low-laying land (shoal) just east of the active lagoon, is a continuous, parallel and slightly-wavy reflectors indicating homogeneous sandy or sandy gravel sediments, and inclined reflectors partly caused by progradation and accumulation of beach sand and gravel. Quasi-continuous, hummocky and chaotic reflectors from the shoal of Nangang village correspond to mixed accumulation of sands and clay. This research indicates the GPR is a non-intrusive, rapid, and economical method for high-resolution profiling of subsurface sediments in sandy gravelly coast. 相似文献
5.
《Basin Research》2018,30(4):766-782
This paper proposes a new methodology to improve the location of potential karstified areas by gravity inversion of a 3D geological model. A geological 3D model is built from surface observations, 2D seismic reflection profiles and well data. The reliability of this geological 3D model obtained from integration, interpretation and interpolation of such data is first tested against the structural consistency of the model. Its theoretical gravimetric response is compared to gravity field during the forward problem in order to evaluate the validity/robustness of the geological model. The coherency between the gravity field and the gravimetric response is tested. The litho‐inversion modelling quantifies the distribution of rock density in a probabilistic way, taking into account the geology and physical properties of rocks, while respecting the geological structures represented in the 3D model. The result of the inversion process provides a density distribution within carbonate formations that can be discussed in term of karstification distribution. Thus, lower densities correlate with areas that are strongly karstified. Conversely, higher than mean densities are found in carbonate formations mostly located under marly and impervious formations, preserving carbonate from karstification and paleokarstification. 相似文献
6.
本文进行了探地雷达在福建漳浦六鳌半岛海岸抛物线沙丘沉积构造探测中的初步应用。结果表明:(1)被探测海岸沙丘的粒度、含水量等理化性质,不同的天线频率,室内数字滤波、增益调适等图像处理环节,均会对探地雷达的探测结果产生影响。(2)本次探测结果以及人工砂坑剖面表明探地雷达是探测海岸沙丘沉积构造的良好手段。(3)通过判读探地雷达图像显示的沉积构造序列组合特点,并根据最近数十年研究区海岸环境演变初步调查结果,认为所探测海岸抛物线沙丘的发育过程,经历了早期海滩脊出露海面、继而发育植被和抛物线沙丘两个阶段。 相似文献
7.
Lateral variability in clinoform trajectory,process regime,and sediment dispersal patterns beyond the shelf‐edge rollover in exhumed basin margin‐scale clinothems 
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下载免费PDF全文 Sediment supply rate and accommodation regime represent primary controls on the depositional architecture of basin margin successions, but their interaction is commonly inferred from 2D dip profiles and/or with limited constraints on sedimentary facies. In this study, three parallel (>40 km long) 2D depositional oblique‐dip profiles from outcrops of the lower Waterford Formation (Karoo Basin, South Africa) have been correlated. This data set provides a rare opportunity to assess the lateral variability in the sedimentary process record of the shelf‐to‐slope transition for eight successive clinothems over a 900 km2 area. The three profiles show similar shelf‐edge rollover trajectories, but this belies significant along‐margin variability in sedimentary processes and down‐dip sediment supply. The depositional architecture of three successive clinothems (WfC 3, 4 and 5) also show along‐shelf physiographic differences. The reconstructed shelf‐edge rollover position is not straight, and a westward curve to the north coincides with an area of greater sand supply to the slope beyond a shelf dominated by wave and storm processes. All the clinothems thicken northwards, indicating an along‐margin long‐term increase in accommodation that was maintained through multiple shoreline transits across the shelf. The origin of the differential subsidence cannot be discriminated confidently between tectonic or compaction processes. The interplay of basin margin physiography, differential subsidence rate and process regime resulted in significant across‐strike variability in the style and timing of sediment dispersal patterns beyond the shelf‐edge rollover. This study highlights the challenge for accurate prediction of the sediment partitioning across the shelf‐edge rollover in subsurface studies. 相似文献
8.
《Basin Research》2018,30(4):799-815
Since the last century, several geological and geophysical studies have been developed in the Santiago Basin to understand its morphology and tectonic evolution. However, some uncertainties regarding sedimentary fill properties and possible density anomalies below the sediments/basement boundary remain. Considering that this is an area densely populated with more than 6 million inhabitants in a highly active seismotectonic environment, the physical properties of the Santiago Basin are important to study the geological and structural evolution of the Andean forearc and to characterize its seismic response and related seismic hazard. Two and three‐dimensional gravimetric models were developed, based on a database of 797 compiled and 883 newly acquired gravity stations. To produce a well‐constrained basement elevation model, a review of 499 wells and 30 transient electromagnetic soundings were used, which contribute with basement depth or minimum sedimentary thickness information. For the 2‐D modelling, a total of 49 gravimetric profiles were processed considering a homogeneous density contrast and independent regional trends. A strong positive gravity anomaly was observed in the centre of the basin, which complicated the modelling process but was carefully addressed with the available constrains. The resulting basement elevation models show complex basement geometry with, at least, eight recognizable depocenters with maximum sedimentary infill of ~ 500 m. The 3‐D density models show alignments in the basement that correlates well with important intrusive units of the Cenozoic and Mesozoic. Along with interpreted fault zones westwards and eastwards of the basin, the observations suggest a structural control of Santiago basin geometry, where recent deformation associated with the Andean contractional deformation front and old structures developed during the Cenozoic extension are superimposed to the variability of river erosion/deposition processes. 相似文献
9.
沙丘层序的建立一直是风沙地貌与沙漠第四纪地质研究中的一个难点问题,而揭示沙丘沉积构造是解决该问题的基础和关键。探地雷达（GPR）是近年兴起的探测沙丘沉积构造的较新和较有效的手段,因风成沙沉积具有均一性好、低电导性、低含水性及低密度性等特点,使GPR在沙丘探测中得到良好的探测效果。借助GPR可研究：（1）一般沙丘的构造和层序、高大沙丘的浅层构造与层序、横向沙山的较完整层序等;（2）沙丘历史时期的移动方向和速率、沙丘的发育过程;（3）沙丘与沙漠的环境变化过程;（4）沙丘和沙漠的水文信息等。在应用过程中,需要注意沙丘含水量、电磁波频率选择、杂波干扰、波速理论值与实际偏差、数据处理和图像解译等方面的问题。目前,GPR在沙漠研究中尚未普及,本文旨在通过综述其在沙漠研究中的进展和存在问题,以期促进GPR在沙丘发育过程和沙漠演化过程研究中的应用。 相似文献
10.
巴丹吉林沙漠湖相沉积的探地雷达图像及光释光年代学证据 总被引：2，自引：1，他引：1
应用探地雷达对巴丹吉林沙漠南部高大沙丘下伏地层进行了探测,在探地雷达剖面沿线采集湖相沉积样品进行光释光测年。对探地雷达数据进行了处理与图像解译,探地雷达反射波与沉积相有相关关系,根据探地雷达数据与沉积信息重建沙丘下伏结构与沉积环境。研究发现,巴丹吉林沙漠南部该测区下伏地形平坦,流沙覆盖区的风成沙是覆盖在古湖相沉积层之上的。样品光释光测年结果反映,在MIS 5e阶段和MIS3阶段,巴丹吉林沙漠南部存在大湖期或高湖面,之后湖相沉积物或钙质胶结层与风成沙因不同的干湿环境而交替叠积; 局部流沙覆盖区甚至在距今7 ka前后还存在有浅湖-沼泽环境。质言之,在巴丹吉林沙漠高大沙丘的形成过程中,气候的多次波动是主要因素之一。 相似文献
11.
Mauricio Parra Andrés Mora Carlos Jaramillo Vladimir Torres Gerold Zeilinger Manfred R. Strecker 《Basin Research》2010,22(6):874-903
In order to evaluate the relationship between thrust loading and sedimentary facies evolution, we analyse the progradation of fluvial coarse‐grained deposits in the retroarc foreland basin system of the northern Andes of Colombia. We compare the observed sedimentary facies distribution with the calculated one‐dimensional (1D) Eocene to Quaternary sediment‐accumulation rates in the Medina wedge‐top basin and with a three‐dimensional (3D) sedimentary budget based on the interpretation of ～1800 km of industry‐style seismic reflection profiles and borehole data. Age constraints are derived from a new chronostratigraphic framework based on extensive fossil palynological assemblages. The sedimentological data from the Medina Basin reveal rapid accumulation of fluvial and lacustrine sediments at rates of up to ～500 m my?1 during the Miocene. Provenance data based on gravel petrography and paleocurrents reveal that these Miocene fluvial systems were sourced from Upper Cretaceous and Paleocene sedimentary units exposed to the west in the Eastern Cordillera. Peak sediment‐accumulation rates in the upper Carbonera Formation and the Guayabo Group occur during episodes of coarse‐grained facies progradation in the early and late Miocene proximal foredeep. We interpret this positive correlation between sediment accumulation and gravel deposition as the direct consequence of thrust activity along the Servitá–Lengupá faults. This contrasts with one class of models relating gravel progradation in more distal portions of foreland basin systems to episodes of tectonic quiescence. 相似文献
12.
拉斯曼丘陵区风力强度大、频数高，各月平均风速均可起动粗砂级以上碎屑。高速气流的极不饱和挟砂（雪晶）状态限制了风力堆积作用和磨蚀作用，而风力吹蚀作用和雪粒（晶）堆积作用则构成本区风力地貌发育的主体。风积方式包括遇阻堆积和停滞堆积，其地貌形态主要有雪被（雪坝）、砂堆（砂地）和砾堤（砾滩）。风积物的沉积地球化学参数与本区母岩有极高的相似性，说明风积碎屑是近源堆积 相似文献
13.
晋北沙漠化地区风沙环境信息服务系统设计 总被引：1，自引：1，他引：0
“3S”技术的发展为大范围风沙环境特征分析提供了重要的技术保障。传统的遥感影像处理软件和GIS软件无法满足植被盖度、土壤风蚀量和地表对大气释尘量等风沙环境信息的计算、评估和空间可视化需求。本文以晋北沙漠化地区遥感数据为基础信息,结合研究区地质、地理、气象和水文等多源信息资料,基于空间数据引擎技术和数据库技术,以C#语言、ENVI/IDL和ArcGIS Engine为混合开发平台,设计开发了晋北沙漠化地区风沙环境信息服务系统,详细阐述了该系统设计的目标和技术路线及该系统的体系结构和功能,形成了基于“3S”技术的典型区域风沙环境信息服务平台的设计思路和方法。该系统可为防治晋北地区土地沙漠化,减轻风沙危害,改善和减缓沙区生态环境日趋恶化的局面提供科技支撑。 相似文献
14.
《Norsk geografisk tidsskrift. Norwegian journal of geography》2012,66(4):169-181
The bed topography of Jutulstraumen is of interest in connection with glaciological modelling for climatic and geological studies. During the Norwegian Antarctic Research Expedition 1996/97 (NARE 96/97) 971 km of bed topography profiles were mapped using ground-penetrating radar (GPR) and a global positioning system (GPS). As additional information to the GPR data for the map compilation, surface features connected to the bed topography were identified in optical satellite images, and relative velocities derived from interferometric synthetic aperture radar (INSAR) data were interpreted using principles of ice flow related to the bed topography. Grids (250 x 250 m) covering the area 73° to 71°S, 0° to 4°E of bed topography and ice thickness were developed. Several observations are confirmed by the independent data sets. The Jutulstraumen outlet glacier shows extreme topography with subglacial plateaus and deep valleys due to faulting. A previously unmapped valley in connection with the fault system is identified. The data sets provide evidence of a grounding line position 6-20 km further inland than previously expected, and a trough occurs 60 km up-glacier from this position. 相似文献
15.
呼伦贝尔沙地风蚀坑粒度特征及其环境意义 总被引：3，自引：3，他引：0
对呼伦贝尔沙地现代风蚀坑表层沙质沉积物与坑后沙丘垂直剖面沉积物进行了粒度分析,讨论了坑后沙丘剖面的形成过程及风成沙粒度变化的原因。结果表明：呼伦贝尔沙地风蚀坑表面及坑后沙丘剖面沉积物粒径以细沙和中沙为主;风蚀坑表面沉积物粒径及分选参数在风蚀坑各部位呈现波动式变化;平坦草地上的现代土壤与坑后沙丘下伏古土壤为同一层。基于粒度和沙丘移动过程综合分析,认为坑后沙丘剖面中风成沙粒度的垂向变化与沙丘在堆积和移动过程中剖面在坑后沙丘相对位置的变化具有紧密联系,密集采样得出的剖面中风成沙粒度的垂向变化是否能直接指示区域气候环境变化值得商榷。 相似文献
16.
Three‐dimensional (3D) numerical modelling of fault displacement enables the building of geological models to represent the complex 3D geometry and geological properties of faulted sedimentary basins. Using these models, cross‐fault juxtaposition relationships are predicted in 3D space and through time, based on the geometries of strata that are cut by faults. Forward modelling of fault development allows a 3D prediction of fault‐zone argillaceous smear using a 3D application of the Shale Gouge Ratio. Numerical models of the Artemis Field, Southern North Sea, UK and the Moab Fault, Utah, USA are used to demonstrate the developed techniques and compare them to traditional one‐ and two‐dimensional solutions. These examples demonstrate that a 3D analysis leads to significant improvements in the prediction of fault seal, the analysis of the interaction of the sealing properties of multiple faults, and the interpretation of fault seal within the context of sedimentary basin geometry. 相似文献
17.
The physical scale modelling of braided alluvial architecture and estimation of subsurface permeability 总被引：1，自引：0，他引：1
The quantitative modelling of fluvial reservoirs, especially in the stages of enhanced oil recovery, requires detailed three‐dimensional data at both the scale of the channel belt and within‐channel. Although studies from core, analogue outcrop and modern environments may partially meet these needs, they often cannot provide detail on the smaller‐scale (i.e. channel‐scale) heterogeneity, frequently suffer from limited three‐dimensional exposure and cannot be used to examine the influence of different variables on the process–deposit relationship. Physical modelling offers a complementary technique that can address many of these quantitative requirements and holds great future potential for integration with reservoir modelling. Physical modelling provides the potential to upscale results and derive reservoir information on three‐dimensional facies geometry, connectivity and permeability. This paper describes the development and use of physical modelling, which employs generic Froude‐scaling principles, in an experimental basin that permits aggradation in order to model the morphology and subsurface depositional stratigraphy of coarse‐grained braided rivers. An example is presented of a 1:50 scale model based on the braided Ashburton River, Canterbury Plains, New Zealand and the adjacent late Quaternary braided alluvium exposed in the coastal cliffs. Critically, a full, bimodal grain size distribution (20% sand and 80% gravel) was used to replicate the prototype, which allows the realistic reproduction of the surface morphology and importantly permits grain size sorting during deposition. Uncertainties associated with the compression of time, sediment mass balance and the hydrodynamics of the finest particle sizes do not appear to affect the reproducibility of stratigraphy between experimental and natural environments. Sectioning of the preserved sedimentary sequence in the physical model allows quantification of the geometry, shape, spatial distribution and internal sedimentary structure of the coarse‐ and fine‐grained facies. A six‐fold facies scheme is proposed for the model braided alluvium and a direct link is established between the grain size distribution and facies type: this allows permeability to be estimated for each facies, which can be mapped onto two‐dimensional vertical cross‐sections of the preserved stratigraphy. Results demonstrate the dominance of four facies based on permeability that range over three orders of magnitude in hydraulic conductivity. Quantification of such variability, and linkage to both vertical proportion curves for facies distribution and connectivity presents significant advantages over other methodologies and offers great potential for the modelling of heterogeneous braided river sediments at the within channel‐belt scale. This paper outlines how physical models may be used to develop high‐resolution, geologically‐accurate, object‐based reservoir simulation models. 相似文献
18.
GIS和GOCAD支持下的矿山3D地质建模 总被引：1，自引：1，他引：0
在综合分析3D地质数据模型的基础上.提出将源数据模型分为GIS可描述和GIS不可描述数据模型的分类方法,在ArcGIS和G0(:AD平台下构建了基于GIS的多元、多方法集成的矿山3D地质模型.ArcGIS平台下描述GIS可描述数据模型,并进行数据管理和空间数据分析;GIS不可描述数据模型一方面在GOCAD下描述复杂的地质构造,另一方面采用面向对象的聚合派生法描述矿山工程模型中的空间实体,并利用Geodatabase建立两者的关联.实例应用表明,该方法保持了数据在空间和时间上的一致性,为矿山安全生产管理提供了有效和可靠的空间数据及可视化支持. 相似文献
19.
Constraining basin thermal history and petroleum generation using palaeoclimate data in the Piceance Basin,Colorado 下载免费PDF全文
下载免费PDF全文 Yao Tong Daniel E. Ibarra Jeremy K. Caves Tapan Mukerji Stephan A. Graham 《Basin Research》2017,29(4):542-553
Careful assessment of basin thermal history is critical to modelling petroleum generation in sedimentary basins. In this paper, we propose a novel approach to constraining basin thermal history using palaeoclimate temperature reconstructions and study its impact on estimating source rock maturation and hydrocarbon generation in a terrestrial sedimentary basin. We compile mean annual temperature (MAT) estimates from macroflora assemblage data to capture past surface temperature variation for the Piceance Basin, a high‐elevation, intermontane, sedimentary basin in Colorado, USA. We use macroflora assemblage data to constrain the temporal evolution of the upper thermal boundary condition and to capture the temperature change with basin uplift. We compare these results with the case where the upper thermal boundary condition is based solely upon a simplified latitudinal temperature estimate with no elevation effect. For illustrative purposes, 2 one‐dimensional (1‐D) basin models are constructed using these two different upper thermal boundary condition scenarios and additional geological and geochemical input data in order to investigate the impact of the upper thermal boundary condition on petroleum source rock maturation and kerogen transformation processes. The basin model predictions indicate that the source rock maturation is very sensitive to the upper thermal boundary condition for terrestrial basins with variable elevation histories. The models show substantial differences in source rock maturation histories and kerogen transformation ratio over geologic time. Vitrinite reflectance decreases by 0.21%Ro, source rock transformation ratio decreases 10.5% and hydrocarbon mass generation decreases by 16% using the macroflora assemblage data. In addition, we find that by using the macroflora assemblage data, the modelled depth profiles of vitrinite reflectance better matches present‐day measurements. These differences demonstrate the importance of constraining thermal boundary conditions, which can be addressed by palaeotemperature reconstructions from palaeoclimate and palaeo‐elevation data for many terrestrial basins. Although the palaeotemperature reconstruction compiled for this study is region specific, the approach presented here is generally applicable for other terrestrial basin settings, particularly basins which have undergone substantial subaerial elevation change over time. 相似文献
20.
Hydrostatic or “normal” pressure can be easily visualized as a water column with pressure given by ρgh and any departures classified as abnormal pressure. This is the basis for commonly used hydrostatic pressure depth trends in sedimentary basins that are constructed on assumptions of constant gradients and are datumed at mean sea level or ground level. But the straightforward water column concept does not upscale in a simple way to sedimentary basins where the zones of interest are several thousands of metres below the land or sea surface. Sedimentary basins are heterogeneous, including stacked, confined reservoirs and variations in pore water composition. It is possible to construct pressure-depth profiles that honour the geology and hydrostratigraphy of a basin and these give different hydrostatic baselines from simple constant gradients hung from familiar local datums such as ground level. Key steps are using a reservoir-specific datums such as the water table or potentiometric surface relevant to that unit, then building a pressure-depth trend that represents the pore fluid salinity variation and density profile throughout the reservoir unit. At a given depth, this version of hydrostatic may predict pressures several hundred psi different from a single density gradient hung from a datum local to the well, and exhibit a notched profile reflecting the geological and hydrological stratigraphy. This construct redefines normal and abnormal pore fluid pressures in sedimentary basins. The impacts of this alternative approach to sedimentary basin hydrostatics, even if data are limited and pressure profiles have to be framed probabilistically, extend to many aspects of studying and interacting with fluid systems in sedimentary basins including basin modelling, petroleum systems analysis, well planning and well operations. 相似文献