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1.
文章介绍了国外海堤生态化建设技术的研究进展,包括海堤结构改造和绿植化研究,其中,海堤结构改造包括建造阶梯式海堤、海堤表面微栖息地改造、建造栖息地长凳、模拟岩石栖息地和海堤绿植化等。国外主要对海堤表面生境进行修复,国内研究则集中在海堤生态化建设的工程技术和采用生态护坡材料对传统海堤进行改造上。在结合海堤生态化相关研究的基础上,对我国海堤生态化建设提出了完善海堤生态化建设技术规范体系、加强海堤生态化关键技术研究、开展海堤生态化适宜性分析和生态化后监管系统等建议。  相似文献   
2.
《地学前缘(英文版)》2020,11(5):1477-1494
The gold deposits in the Youjiang basin,totaling 25 Moz gold,have traditionally been thought to be of Carlintype,particularly those with extensional structural geometries in the northern basin dominated by platform sedimentary sequences.However,the structural geometries,mineralization styles and alteration types for the Jinya,Gaolong and Nakuang gold deposits in the south-central part of the basin are remarkably similar to those of unequivocal orogenic gold deposits.Structural studies show that gold mineralization in the three gold deposits was controlled by tight "locked-up"anticlines with NW—SE-to E-W-trending and/or concomitant thrusts and/or shear zones,which resulted from NE-SW-to N-S-trending compression or transpression following the Early Triassic closure of the Paleo-Tethyan Ocean.Alteration zones in these deposits are dominated by silicification(quartz),sericitization,sulfidation and carbonation.Zoned pyrites in these deposits comprise Au-poor cores and invisible Au-bearing rims with minor external free gold.Euhedral to subhedral auriferous arsenopyrites also contribute to the gold budget.These features indicate that the three gold deposits are sediment-hosted orogenic gold deposits that contrast markedly with the Carlin-type gold deposits in the northern part of the Youjiang basin in terms of structural geometry and timing,mineralization style and nature of associated alteration.Although additional reliable ages using robust methodologies are still required,the older isotopic ages of the gold deposits in the south-central Youjiang basin are also consistent with earlier formation during transpression that predated extension during orogenic collapse,the period of formation of the Carlin-type gold deposits in the northern Youjiang basin.  相似文献   
3.
The West Junggar Orogenic Belt(WJOB)in northwestern Xinjiang,China,is located in the core of the western part of the Central Asian Orogenic Belt(CAOB).It has suffered two stage tectonic evolutions in Phanerozoic,before and after the ocean–continental conversion in Late Paleozoic.The later on intracontinental deformation,characterized by the development of the NE-trending West Junggar sinistral strike-slip fault system(WJFS)since Late Carboniferous and Early Permian,and the NW-trending Chingiz-Junggar dextral strike-slip fault(CJF)in Mesozoic and Cenozoic,has an important significance for the tectonic evolution of the WJOB and the CAOB.In this paper,we conduct geometric and kinematic analyses of the WJOB,based on field geological survey and structural interpretation of remote sensing image data.Using some piercing points such as truncated plutons and anticlines,an average magnitude of^73 km for the left-lateral strike-slip is calculated for the Darabut Fault,a major fault of the WJFS.Some partial of the displacement should be accommodated by strike-slip fault-related folds developed during the strike-slip faulting.Circular and curved faults,asymmetrical folds,and irregular contribution of ultramafic bodies,implies potential opposite vertical rotation of the Miao’ergou and the Akebasitao batholiths,resulted from the sinistral strike-slipping along the Darabut Fault.Due to conjugate shearing set of the sinistral WJFS and the dextral CJF since Early Mesozoic,superimposed folds formed with N–S convergence in southwestern part of the WJOB.  相似文献   
4.
车排子凸起与沙湾凹陷过渡带的构造模型   总被引:1,自引:0,他引:1       下载免费PDF全文
车排子凸起位于准噶尔盆地扎伊尔山前,是夹持在南部四棵树凹陷和东部沙湾凹陷之间的三角构造带。然而对这个三角构造带是原地掩伏构造,山前推覆构造,还是走滑构造控制形成的认识存在争议。目前对于车排子凸起与沙湾凹陷过渡带的构造变形特征以及变形机制的认识尚不清楚。而过渡带是研究该区构造变形与演化的良好区域,精细研究该区域构造几何学与运动学对于揭示其构造变形机制以及认识盆山之间的关系具有积极作用,并对于该区油气勘探具有重要意义。本文以研究区的连片三维地震资料为基础,运用不整合面识别、轴面分析及平衡剖面等方法,对车排子凸起与沙湾凹陷过渡带进行精细的构造解析、建模与构造复原。研究表明,过渡带发育下二叠统(P1j-P1f),中二叠统(P2x-P2w),上二叠统(P3w),三叠系(T),侏罗系(J),白垩系(K)与古近系-第四系(E-Q)7个构造变形层序。发育佳木河组底部及石炭系内部滑脱层。深部(前二叠系)构造楔发育于整个过渡带,其个数和几何学形态的变化直接影响了上覆背斜形态。构造楔在早二叠世开始楔入,挤压作用持续至三叠纪末期。晚三叠世发育生长地层,显示了P-T构造层褶皱变形的时间,随后三叠纪末期,过渡带受到来自西北缘造山带方向的逆冲推覆构造的叠加作用,表现在后缘发育一系列叠瓦构造,推覆距离约为8 km,南部逆冲断层上盘二叠系-三叠系被剥蚀完全,北部残余少量下二叠统佳木河组。  相似文献   
5.
克拉苏构造带构造非常复杂,经过30余年的油气勘探开发,构造规律不清楚、构造圈闭不落实的问题仍然非常突出。本文通过大量三维地震资料的构造解释、建模及实钻资料验证,发现克拉苏构造带在剖面上呈分段分层变形、平面上呈雁列式展布特征。提出克拉苏构造带两种协同变形机制,较好地解释了在膏盐层调节作用下盐上、盐层、盐下3个构造层的差异变形现象。结合遥感影像及重力异常影像分析了盆山耦合关系,提出了南天山造山带的差异隆升推覆作用,南部温宿、新和、牙哈古隆起的阻挡作用和古近系膏盐层的调节作用是变形的3个主要影响因素,并据此较好地解释了克拉苏构造带构造圈闭平面展布格局。  相似文献   
6.
异质性是岩体的重要属性之一,从岩体的物质组成到结构特征,再到微宏观力学行为表现,异质性现象普遍存在。本文在梳理已有研究成果的基础上,从岩体的细微观异质性、结构面异质性和宏观异质性3个不同的尺度,对异质性的产生原因、表现特征、力学效应和时空演化规律等进行阐述,并介绍了相关研究方法以及异质性在不同尺度上的差异表现。岩体异质性的研究,是岩体工程地质力学理论体系的延伸,而多尺度的研究方法也成为全面揭示岩体变形破坏机制的一种有效手段。  相似文献   
7.
在谷德振先生“水文地质结构”学术思想指引下,本文提出建立结构水文地质学的设想,论述了其基础理论框架。从方法论角度将矿山水害防控分为被动防控和主动防控两种方法。以结构水文地质学指导煤矿高势能突水溃砂防控,分析了被动防控可能产生突水溃砂灾害的机理; 提出了主动地质工程防控的原理,包括地质材料性质改造、结构隔水性能重构、赋存水动力环境改造、减轻采掘诱发覆岩破坏等具体方法。抛砖引玉,以期催生符合中国矿山防治水实践需要的创新理论和方法。  相似文献   
8.
《China Geology》2021,4(4):541-552
The intersection of the Kyushu-Palau Ridge (KPR) and the Central Basin Rift (CBR) of the West Philippine Basin (WPB) is a relic of a trench-trench-rift (TTR) type triple-junction, which preserves some pivotal information on the cessation of the seafloor spreading of the WPB, the emplacement and disintegration of the proto-Izu-Bonin-Mariana (IBM) Arc, and the transition from initial rifting to steady-state spreading of the Parece Vela Basin (PVB). However, the structural characteristics of this triple-junction have not been thoroughly understood. In this paper, using the newly acquired multi-beam bathymetric, gravity, and magnetic data obtained by the Qingdao Institute of Marine Geology, China Geological Survey, the authors depict the topographic, gravity, and magnetic characteristics of the triple-junction and adjacent region. Calculations including the upward continuations and total horizontal derivatives of gravity anomaly are also performed to highlight the major structural features and discontinuities. Based on these works, the morphological and structural features and their formation mechanisms are analyzed. The results show that the last episode amagmatic extension along the CBR led to the formation of a deep rift valley, which extends eastward and incised the KPR. The morphological and structural fabrics of the KPR near and to the south of the triple-junction are consistent with those of the western PVB, manifesting as a series of NNE-SSW- and N-S-trending ridges and troughs, which were produced by the extensional faults associated with the initial rifting of the PVB. The superposition of the above two reasons induced the prominent discontinuity of the KPR in deep and shallow crustal structures between 15°N–15°30′N and 13°30′N–14°N. Combined with previous authors’ results, we propose that the stress produced by the early spreading of the PVB transmitted westward and promoted the final stage amagmatic extension of the CBR. The eastward propagation of the CBR destroyed the KPR, of which the magmatism had decayed or ceased at that time. The destruction mechanism of the KPR associated with the rifting of the PVB varies along strike the KPR. Adjacent to the triple-junction, the KPR was destroyed mainly due to the oblique intersection of the PVB rifting center. Whereas south of the triple-junction, the KPR was destroyed by the E-W-directional extensional faulting on its whole width.©2021 China Geology Editorial Office.  相似文献   
9.
乔梁  张强  岳平  金红梅 《大气科学》2019,43(2):251-265
利用中国西北中部具有代表性的非季风区、夏季风影响过渡区和季风区的7个高空站的2013年夏季晴天07时、13时、19时(北京时)的大气边界层资料,通过分析大气边界层位温、比湿、风速的垂直结构,发现大气边界层结构及厚度在不同区域的分布特征:稳定边界层厚度、残余层顶高度和对流边界层厚度从非季风区、夏季风影响过渡区至季风区出现阶梯性大幅降低,从非季风区至夏季风影响过渡区,以及从夏季风影响过渡区至季风区,对流边界层厚度降幅依次为25.6%和81.8%,稳定边界层厚度降幅依次为58.3%和41.8%;在稳定边界层条件下,可观察到低空急流的存在,非季风区低空急流出现高度明显高于夏季风影响过渡区和季风区,且非季风区的低空急流风速也明显大于夏季风影响过渡区和季风区。通过分析与大气边界层发展最为密切的陆面热力因素在不同气候区的分布,净辐射值、日地-气温差最大值以及感热通量值在非季风区大于夏季风影响过渡区和季风区,从陆面热力过程为非季风区大气边界层厚度大于夏季风影响过渡区和季风区提供了理论依据。  相似文献   
10.
Urban hierarchies are closely related to economic growth, urban planning and sustainable urban development. Due to the limited availability of reliable statistical data at fine scales, most existing studies on urban hierarchy characterization failed to capture the detailed urban spatial structure information. Previous studies have demonstrated that night time light data are correlated with many urban socio-economic indicators and hence can be used to characterize urban hierarchies. This paper presents a novel method for studying urban hierarchies from night time light data. Night time light data were first conceptualized as continuous mathematical surfaces, termed night time light surfaces. From the morphology of these surfaces the corresponding surface networks were derived. Hereafter, a night time light intensity (NTLI) graph was defined to describe the morphology of the surface network. Then, structural similarity between the night time light surfaces of any two different cities was calculated via a threshold-based maximum common induced graph searching algorithm. Finally, urban hierarchies were defined on the basis of the structural similarities between different cities. Using the 2015 annual NPP-VIIRS night time light data, the urban hierarchies of 32 major cities in China were successfully examined. The results are highly consistent with the reference urban hierarchies.  相似文献   
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