宣郎地区基底构造特征   总被引：1，自引：0，他引：1       下载免费PDF全文

盛勇  李仁和  廖圣柱  薛小健 《地质科学》2014,(2):394-404

本文以宣城-郎溪地区的盆地为重点研究区,综合分析区域性重力、磁法资料,通过地面重力测量技术、高精度地面磁测,大地电磁测深等综合地球物理剖面,建立了宣城-郎溪地区基底构造格架,并探讨了其构造演化史。研究结果显示,宣城-郎溪地区基底构造格架主要呈北东向展布,研究区西部被江南深大断裂带所分割,断裂带北侧为北东向的古生界隆起,断裂带南侧为呈北东向展布的深厚断陷盆地,江南断裂带被一系列北西向断裂所切割,研究区南部主要受周王断裂带控制。此外,本次研究还认为,江南断裂带的北侧与北西断裂带的交汇处是找矿远景区。  相似文献   

The geostatistics of the metal concentrations in sediments from the eastern Brazilian continental shelf in areas of gas and oil production     

《Journal of South American Earth Sciences》2014

Geostatistical techniques were used to evaluate the differences in the geochemistry of metals in the marine sediments along the Eastern Brazilian continental margin along the states of Ceará and Rio Grande do Norte (Northeastern sector) and Espírito Santo (Southeastern sector). The concentrations of Al, Fe, Mn, Ba, Cd, Cu, Cr, Ni, Pb, V, Hg, and Zn were obtained from acid digestion and quantified using flame atomic absorption spectrometry (AAS), inductively coupled plasma mass spectrometry (ICP-MS) and inductively coupled plasma atomic emission spectrometry (ICP-AES). The metals showed a similar order of concentration: Al > Fe > Ba > Mn > V > Ni > Pb > Cr > Zn > Cu, in both the Ceará; and Rio Grande do Norte shelf regions but different in the Espírito Santo shelf (Fe > Al > Mn > Ba > Zn > V > Cr > Ni > Pb > Cu. The concentrations of Hg and Cd were below the detection limit in all areas. A multivariate analysis revealed that the metals of siliciclastic origin on the continental shelf of Ceará are carried by Al. In addition, a large portion of metal deposits is connected to the iron and manganese oxides on the continental margin of Rio Grande do Norte. The metals from the continental supply on the coast of Espírito Santo (Cu, Ni, Ba, and Mn) are associated with Al; whereas Cr, Pb, V, and Zn are associated with iron in this southern area. Geochemical evaluations are needed to distinguish the origin and mineralogical differences of marine sediments within the regions. Scanning electron microscopy/energy dispersive spectrometry (SEM/EDS) applied to the sediments from the coast of Ceará showed the morphological diversity of sediment grains: biological fragments, multifaceted particles, aggregates, and crystals occurred in the three regions analyzed. Among these grains, calcite, Mg-calcite, and aragonite were predominant in the northeastern sector, whereas silicates and other minerals were predominant the southeastern sector. Mg, K, Ti, and Zr as well as the lanthanides La and Ce were identified using SEM/EDS and added to the geochemical analysis of the data.  相似文献   

黄海大海洋生态系区域监测体系建设的对策建议          下载免费PDF全文

王孝程  贾川  张怡  靳青青  王紫竹  刘永健  王燕  邵魁双  王守强  关春江  郭皓 《海洋开发与管理》2022,39(2):88-94

为促进黄海生态环境保护和生态灾害治理工作,文章基于历史资料的收集和整理,分析黄海大海洋生态系的生态环境背景及其存在的问题,并提出区域监测体系建设的对策建议。研究结果表明:黄海大海洋生态系的气候变化和营养盐变化是浮游生物群落的重要影响因素,赤潮、绿潮和水母暴发是黄海大海洋生态系的主要生态灾害;应通过加强各种形式的监测和合作,不断构建黄海大海洋生态系区域监测体系。  相似文献   

陆海统筹防治海洋污染政策是否行之有效——来自合成控制法的检验          下载免费PDF全文

胡求光  余璇 《海洋开发与管理》2022,39(2):3-10

为推进我国海洋经济和海洋生态环境的高质量和可持续发展,文章以浙江省防治海洋污染政策为例,基于2006—2017年我国48个沿海地区的面板数据,运用合成控制法定量评价陆海统筹防治海洋污染政策对宁波市海洋污染的影响,并对评价结果进行稳健性检验。研究结果表明:《浙江省近岸海域污染防治规划》围绕陆海统筹理念制定,2013年实施后有效缓解宁波市的海洋污染,促降效应的发挥同时存在时间上的滞后性和持续性,地区安慰剂和替换处理组的检验策略均证实该评价结果的稳健性。研究结果可为运用陆海统筹理念防治海洋污染提供重要的实证支持。  相似文献   

基于CiteSpace的海洋空间规划研究进展分析          下载免费PDF全文

李思达  张海峰  徐敏 《海洋开发与管理》2022,39(1):23-30

文章基于CiteSpace对2000-2020年海洋空间规划研究进行了知识图谱和可视化分析,分析发文量、作者、机构、期刊影响力和合作网络变化,揭示研究热点的变化趋势。研究表明:欧美等经济发达国家和澳大利亚具有较高影响力,国家与机构间合作密切。海洋空间规划研究始终以生态系统和环境保护为中心,研究内容以政策研究和生态环境研究为主,研究热点由关注生态功能转变为以人类活动为主的整体功能规划研究,蓝色经济、蓝色发展是近些年的主要关键词。在海洋开发强度、范围不断增大,全球气候环境频繁变化的背景下,加强海洋观测和数据收集,探索海洋生态系统对环境影响和人类活动响应机制,加强生态模型在海洋应用,细化海洋空间规划管理措施,因海制宜地调整规划方案,实现生态保护和经济发展的齐头并进,是我国海洋空间规划研究的未来方向。  相似文献   

海底电缆工程对中华白海豚的影响研究——以厦门英春—围里海底电缆工程为例          下载免费PDF全文

陈斯婷  杨淑珍  陈斌  姜尚 《海洋开发与管理》2022,39(9):31-35

中华白海豚是国家一级重点保护水生哺乳动物,厦门湾是中华白海豚的重要栖息地之一。文章以厦门英春—围里海底电缆工程为例,评价工程建设对中华白海豚及其栖息地的影响,并提出中华白海豚的保护措施,以期为海洋工程建设对水生野生保护动物的保护管理提供借鉴。  相似文献   

我国海洋型城市旅游竞争力评价及提升路径研究          下载免费PDF全文

杨德进  史银辉  陈佩瑶 《海洋开发与管理》2022,39(3):33-42

随着海洋旅游时代的到来,我国迎来了海洋旅游发展的良好契机,海洋型旅游城市作为重要的旅游目的地类型之一,其旅游竞争力近年来受到各界关注。文章从海洋型旅游城市特征出发,建立海洋型城市旅游竞争力评价指标体系,进而将海洋型城市旅游竞争力分为旅游资源竞争力、旅游基础设施竞争力、旅游行业竞争力以及旅游环境支持竞争力四大部分。进一步基于因子分析法和聚类分析法对我国51个海洋旅游城市的旅游竞争力进行实证分析,得出城市旅游竞争力得分排名。最后根据分析结果,从旅游资源、旅游基础设施、旅游产业、旅游环境支撑、整体旅游等方面提出我国海洋型城市旅游竞争力的提升路径,为促进我国海洋型旅游城市整体竞争力的提升提出指导建议。  相似文献   

How EU policies could reduce nutrient pollution in European inland and coastal waters     

《Global Environmental Change》2021

Intensive agriculture and densely populated areas represent major sources of nutrient pollution for European inland and coastal waters, altering the aquatic ecosystems and affecting their capacity to provide ecosystem services and support economic activities. Ambitious water policies are in place in the European Union (EU) for protecting and restoring aquatic ecosystems under the Water Framework Directive and the Marine Strategy Framework Directive. This research quantified the current pressures of point and diffuse nitrogen and phosphorus emissions to European fresh and coastal waters (2005–2012), and analysed the effects of three policy scenarios of nutrient reduction: 1) the application of measures currently planned in the Rural Development Programmes and under the Urban Waste Water Treatment Directive (UWWTD); 2) the full implementation of the UWWTD and the absence of derogations in the Nitrates Directive; 3) high reduction of nutrient, using best technologies in wastewaters treatment and optimal fertilisation in agriculture. The results of the study show that for the period 2005–2012, the nitrogen load to European seas was 3.3–4.1 TgN/y and the phosphorus load was 0.26–0.30 TgP/y. Policy measures supporting technological improvements (third scenario) could decrease the nutrient export to the seas up to 14% for nitrogen and 20% for phosphorus, improving the ecological status of rivers and lakes, but widening the nutrient imbalance in coastal ecosystems (i.e. increasing nitrogen availability with respect to phosphorus), affecting eutrophication. Further nutrient reductions could be possible by a combination of measures especially in the agricultural sector. However, without tackling current agricultural production and consumption system, the reduction might not be sufficient for achieving the goals of EU water policy in some regions. The study analysed the expected changes and the source contribution in different European regional seas, and highlights the advantages of addressing the land-sea dynamics, checking the coherence of measures taken under different policies.  相似文献   

High resolution local Moho determination using gravity inversion: A case study in Sri Lanka     

《Journal of Asian Earth Sciences》2013

The seismic data incorporated in global Moho models are sparse and therefore the interpolation of global Moho depths on a local area may give unrealistic results, especially in regions without adequate seismic information. Gravity inversion is a useful tool that can be used to determine Moho depths in the mentioned regions. This paper describes an interactive way of local Moho depth determination using the gravity inversion method constrained with available seismic data. Before applying inversion algorithms, the Bouguer gravity data is filtered in various stages that reduce the potential bias usually expected in Moho depth determination using gravity methods with constant density contrast assumption. A test area with reliable seismic data is used to validate the results of Moho computation, and subsequently the same computation procedure is applied to the Sri Lankan region. The results of the test area are in better agreement with seismically determined Moho depths than those obtained by global Moho models. In the Sri Lankan region, Moho determination reveals a fairly uniform thin crust of average thickness around 20 km. The overall result suggests that our gravity inversion method is robust and may be suitable for local Moho determination in virgin regions, especially those without sufficient seismic data.  相似文献   

http://www.sciencedirect.com/science/article/pii/S1674987113000340     

Suman Kilaru  Bandaru Karunakar  Goud Vijay  Kumar Rao 《地学前缘(英文版)》2013,4(6):717-728

Regional surface gravity data and global satellite magnetic data have been utilized to generate a preliminary model of the crustal structure along a southwest-northeast profile （Gadra-Fatehpur） through western Rajasthan.The study area represents the western part of the Indian continental landmass which has undergone several major episodes of repeated subduction/collision,plume traces and rifting from Archaean to recent times.The temporal and spatial relationship between the various geotectonic provinces is quite complex,thereby limiting the emergence of a suitable crustal structure model for this region.Exposures of the Malani Igneous Suite （MIS）,a product of bimodal volcanism （～780 Ma）,and considered to be the third largest felsic magmatic province of the world,is evident along the profile and also to the southwest of the study area.The easternmost part of the profile is close to the DAFB （Delhi Aravalli Fold Belt）,a Proterozoic orogenic belt.This study probes the geometry of the different crustal units in terms of density and susceptibility variations in order to decipher the imprints of the major tectonic processes the region has undergone.In order to decipher the crustal geometry of the Gadra-Fatehpur profile,two NW-SE gravity and magnetic profile vertical sections （A-A＇ in the south and B-B＇ in the north） are modelled on the basis of the constraints provided from previous seismic models.The crustal model of the Gadra-Fatehpur profile is composed of alluvium,Tertiary sediments,MIS,Marwar Supergroup,low-density layers （LDLs） and the middle-lower crustal layers,with a distinct change in configuration from the southwest to northeast.The Moho dips from SW to NE,the MIS in the SW gives way to the thick pile of the Marwar Supergroup to the NE.The evolution of MIS has been suggested to have occurred as a consequence of delamination of the upper mantle.LDLs are incorporated in Gadra-Fatehpur model.In the SW,LDL （2550 kg/m3） lies below the MIS in the NE,another LDL （2604 kg/m3） is depicted below the mid-crustal layer.  相似文献