首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 41 毫秒
1.
在仙女山-九畹溪断裂带野外地质调查的基础上采集12件断层泥样品,并对样品进行石英碎砾提取和扫描电镜微形貌观察。结果表明,仙女山断裂为一条以粘滑为主的活动断裂,最近一次较大规模的运动发生在中-晚更新世;九畹溪断裂带具有多期活动迹象,早期活动强于晚期,近期强烈活动在上新世至中更新世,为一条以粘滑运动为主的活动断裂。仙女山-九畹溪断裂带所构成的V型断裂组合表现为以仙女山断裂带为主导的构造格局。  相似文献   

2.
通过野外地震地质调查,发现:(1)北东向新场—古老背断裂带的地表形迹和更新世多期活动的地层、构造岩证据;(2)近南北向虎牙第四纪断层及其粘滑快速断错的剩余形变特征;(3)北西向天阳坪断裂带南支早第四纪粘滑快速断错的剩余形变特征及其上覆晚更新世末期堆积(14C16400±439年)未受断错所揭示的时间上限约束。  相似文献   

3.
本文通过近10年跨仙女山、天阳坪断裂带上6处短水准垂直形变资料分析,指出:控制葛洲坝库区西南邻域地壳垂直形变的是仙女山断裂;其断层东(下)、西(上)盘升降趋势,受力状态南北地段不一致,且发生明显的反向运动。前5年(1981—1985年),南段的东盘下降,区域力为挤压;北段东盘上升,区域力为拉张,1985年后发生明显的反向运动。库区南侧的天阳坪断裂的东段近期较稳定,西段变化则是受仙女山断层变化的影响,产生同步运动,东西向的区域力对断层两盘的作用一致。1988年12月16日兴山县北发生M_L为3.9级地震,认为与仙女山断层明显的反向运动关系密切,断层运动趋势及其与地震的关系有待今后进一步探索。由于库区西部仙女山断层的活动,能量有所释放,不可能发生大震,因此库区及大坝比较安全。  相似文献   

4.
北北西向上地壳板桥断裂带位于神农架三角形穹状断块西缘 ,长达 50 km,走向330°,倾向南西 ,倾角 45°~ 85°,具有左旋走滑的新构造运动特征 ,发育宽大的新构造强变形带和断层破碎带 ,切割第四纪断层堆积。其灰黑色断层岩粉年代鉴定值为1 4 C 2 970 0± 60 0 a和 1 890 0± 660a,显示了晚更新世末期的断层新活动。分段性研究将其评定为 6级潜在震源区。  相似文献   

5.
本文利用经过拟稳和伪逆平差等方法处理过的大地测量资料,分析了鲜水河断裂带的现今构造形变。表明该断裂带在近东西向区域压应力作用下,呈压性反扭,为典型的蠕滑—粘滑型断裂带。 断裂带蠕动段以水平反扭为主,前兆显示“V字型”异常形态,震后呈对数衰减。在虾拉沱,水平蠕动年速率为7.17±0.03毫米,倾向蠕动年速率为1.04±0.03毫米,两者之比为7:1。在粘结阶段,断裂带闭锁段无明显活动;而快速错动阶段,震中区发生大量级的水平反扭错动(达米级)及其伴随的松驰下沉(达分米级)运动。 现今构造形变和历史大震表明:道孚以北为蠕动段,以南为闭锁段。据此,鲜水河断裂带来来如果发生大震,则危险区可能在南段。  相似文献   

6.
用两个相连的“三联点”模拟一条断裂带,在自相似规则下,构造了断裂带内各级断层的分布。引入分形维数,建立了断裂带内各级断层的相对运动速度与断裂带外围(板块或亚板块之间)相对运动速度之间的关系。用圣安德烈斯断裂带的运动数据初步验证了模型给出的断裂带内主断层相对运动速度与板块相对运动速度之间的关系的正确性。引入b值与分维数的关系,获得了由断层相对运动速度计算b值的方法,并得出结论:在板块相对运动速度稳定不变的条件下,主断层相对运动速度的显著增加是断裂带内孕育大地震的中期前兆信息。  相似文献   

7.
仙女山断裂带是鄂西一条区域性活动构造。本文利用重、磁资料、人卫象片地质解释和野外地质调查结果,重点对断裂的延伸规模、切割深度和輓近时期的活动性提出了讨论,指出该断裂带是一条基底大断裂,其北段已过长江,是黄陵断块构造的西部边界。由于輓近时期的断裂活动,仙女山断裂是鄂西一条不可忽视的地震构造带。  相似文献   

8.
焦家金矿田内矿体稳定、规模巨大,勘查深度已超过2000m,探获金金属量已超千吨,是我国重要的金矿产地。矿体严格受NNE向焦家断裂带控制,产状与构造面产状基本一致。从断层岩岩性和构造面表面形态入手,构建了三维构造模型,研究了断层面形态和断层岩岩性差异对成矿的约束作用。系统收集焦家金矿田内500个钻孔地质资料,通过二维三维相结合方式,发现断层岩岩性从浅部向深部发生明显变化,由断层泥渐变为糜棱岩,而上盘矿体数量和蚀变分带也随着断层岩的改变发生明显变化。对构造面进行表面坡度分析,发现矿体主要赋存在表面坡度较小部位,且沿倾向上表面坡度由陡急速变缓部位易于形成厚大矿体。  相似文献   

9.
长乐-诏安断裂带是福建沿海的主要活动断裂之一,沿断裂带曾发生多次破坏性地震,是福建省陆域上的主要发震构造。中国东部地区破坏性地震的发生与晚更新世活动断裂有密切联系,因此研究长乐-诏安断裂带在晚更新世的活动具有重要意义。在对福建省东山县最新发现的长乐-诏安断裂东支东山段剖面的野外详细调查的基础上,通过对断层下盘地层和断层上断点以上地层中钾长石光释光测年,确定了长乐-诏安断裂带东支东山段的具体活动时间在(34.8±8.3)~(48.0±3.5)ka之间,显示该断裂至晚更新世晚期仍有活动,属晚更新世活动断裂;通过震级(M)与地震断层位错量(D)经验关系拟合法估算,该断裂的最大发震能力为6.5~7.0级地震。该晚更新世活动断裂的确定和最大震级估算,为长乐-诏安断裂带的活动性提供了确切年代学证据,为东山县地区城市安全评价提供了依据。  相似文献   

10.
近南北向仙女山断裂带位于湖北宜昌地区西部,是影响葛洲坝和拟建的三峡高坝库区工程稳定性的重要活动构造。因此,它历来引起有关方面的极大关注。据以往地质成果,仙女山断裂带南起五峰县渔洋关,北至秭归荒口,长约100公里。但对该断裂带北延是否过长江众说纷纭。为此,宜昌地区行署地震办公室会同有关单位组成联合考察组,先后于一九八  相似文献   

11.
12.
The ability of cell to modulate the fluidity of plasma membrane was crucial to the survival of microorganism at low temperature. Plasma membrane proteins, fatty acids and carotenoids profiles of Antarctic psychrophilc yeast Rhodotorula sp. NJ298 were investigated at -3 ℃, 0 ℃ and 8 ℃. The results showed that plasma membrane protein content was greater at -3 ℃ than that at 8 ℃, and a unique membrane polypeptide composition with an apparent molecular mass of 94.7 kDa was newly synthesized with SDS-PAGE analysis; GC analysis showed that the main changes of fatty acids were the percentage of unsaturated fatty acids (C18∶ 1 and C18∶ 2) and shorter chain saturated fatty acid (C10∶ 0) increased along with the decrease of the culture temperature from 8 ℃ to -3 ℃; HPLC analysis indicated that astaxanthin was the major functional carotenoids of the plasma membrane, percentage of which increased from 54.6±1.5% at 8 ℃ to 81.9±2.1% at -3 ℃. However the fluidity of plasma membrane which was determined by measuring fluorescence anisotropy was similar at -3 ℃, 0 ℃ and 8 ℃. Hence these changes in plasma membrane's characteristics were involved in the cellular cold-adaptation by which NJ298 could maintain normal plasma membrane fluidity at near-freezing temperature.  相似文献   

13.
正1 Aims and Scope Advances in Polar Science(APS)is an international,peer-reviewed journal jointly sponsored by the Polar Research Institute of China and the Chinese Arctic and Antarctic Administration.APS is a comprehensive academic journal dedicated to presentation of multi-disciplinary achievements in Arctic and Antarctic expeditions and research.Its primary purpose  相似文献   

14.
<正>Copyright Submfnion of a roanusatpt inks:that the work described has not been published before(exoept In the form of an abstrW or as part of a published lecture,review,or thesis);that it is not under consideration for publication elsewhere that its publication has been approved by ail  相似文献   

15.
<正>The Journal of Ocean University of China(Oceanic and Coastal Sea Research)is a comprehensive academic quarterly sponsored by the Ocean University of China,published one volume per year.This journal is devoted to the publication of the theoretical and applied research results on oceanography and marine fisheries.The fieldcovered include the physical,chemical,biological,geo-  相似文献   

16.
<正>The 35th IAHR World Congress was held in Chengdu,China from September 8 to September 132013.The title of the conference was:"The Wise Finds Pleasure in Water:Meandering through Water Science and Engineering".During the congress,1239 papers were presented in 139sessions for oral presentations and 7 sessions for poster presentations.After the Congress,a Committee was appointed to select some of the best papers presented at the Congress for publication,after a  相似文献   

17.
As an important component of the cryosphere,sea ice is very sensitive to the climate change.The study of the sea ice physics needs accurate sea ice thickness.This paper presents an electromagnetic-induction(EM) technique which can be used to measure the sea ice thickness distribution efficiently,and the successful application in Bothnian Bay.Based on the electromagnetic field theory and the electrical properties of sea ice and seawater,EM technique can detect the distance between the instrument and the ice/water interface accurately,than the sea ice thickness is obtained.Contrastive analysis of the apparent conductivity data obtained by EM and the value of drill-hole at same positions allows a construction of a transformable formula of the apparent conductivity to sea ice thickness.The verification of the sea ice thickness calculated by this formula indicates that EM technique is able to get reliable sea ice thickness with average relative error of only 12%.The statistic of all ice thickness profiles shows that the level ice distribution in Bothnian Bay was 0.4-0.6 m.  相似文献   

18.
Based on the hydrographic data in austral summer during the 22nd Antarctic Expedition of China(2005/2006),some features can be found about the northern margin of Emery ice shelf as follows.The heat content in the surface layer(0-50 m) at the eastern end and the western end of the ice-shelf margin is much higher than that at the middle.The upper mixing-layer depth and the seasonal thermocline depth at the middle of the ice-shelf northern margin are much shallower than those at the both ends.However there is much less difference between the middle and the ends in the bottom layer.The remote sensing photos show that the inhomogeneity in the surface-layer water is closely related to the spatial distribution of the floes and polynia in the area.  相似文献   

19.
Phylogenetic analysis based on 16S rDNA of 8 strains of cultivable bacteria isolated from Arctic sea-ice was studied.The results showed that strain BJ1 belonged to genus Planococcus,which was a genus of low mole percent G C gram-positive bacteria;strain BJ6 belonged to genus Burkholderia of β-proteobacteria and the rest 6 strain all belonged to γ-proteobacteria,of which strain BJ8 was a species of Pseudoalteromonas,strain BJ2-BJ5 and BJ7 were members of genus Psychrobacter.Phylogenetic analysis also indicated that bacteria of genus Psychrobacter of the isolates formed a relatively independent phylogenetic cluster in comparison with other bacteria belonged to genus Psychrobacter.  相似文献   

20.
Foreword     
正Rapid changes of Arctic sea ice cover have been in the focus of the international climate research community in recent years.Quite a few of nations have completed a large number of related surveys and research projects in the Arctic Ocean.Up to now,China has performed six research cruises to the Arctic Ocean resulting in a significant volume of research output.Improved knowledge on the atmospheree-sea ice-ocean interactions in the Arctic is a  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号