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本文在对天山构造地貌形成、演化及构造地貌特征分析的基础上,对天山作为陆内古板缘山的构造、边界及动力条件进行了研究,进而提出了活动性陆内古板缘山地的造山旋回模式。  相似文献   
2.
采用地下水蓄水构造理论,总结概括地貌构造影响控制的水文地质特征规律,补充完善了按岩石地层控水因素划分的地下水含水岩组类型的不足,更有利于指导地下水资源的科学勘查评价、合理开发利用及有效管理保护。  相似文献   
3.
DuringthelastseveralyearstheRussian-Chinese~tivemorphOStructUralinvestigationswerecarriedoutalongthetransregionalfaultzonewhichstretcheSmorethan3000kin,fromlowerstreamoftheHuanghecaver,ac~theffehaho,Liaohedep~ion,thenalongthehahuaandthelowerAInurvalleystotheNorthffekhalinandprobablytothecentralPartofOkhotskAsbasin.It'soneofthelargestfaultzonesintheeasternrnalginofAsia.OntheterritoryofnortheasternChinathemostpinOfthiszoneiskno~asTall-L.faultzonewhichhasbeenstudiedbyChinesegeologistsform…  相似文献   
4.
基于栅格数字高程模型提取特征地貌技术研究   总被引:71,自引:0,他引:71  
闾国年  钱亚东 《地理学报》1998,53(6):562-570
本文对近年来基于栅格数字高程模型提取特征地貌技术进行了详细的研究,认为该技术的关键在于两个方面:一是如何定义地貌形态结构,二是提取算法的设计。本文提出了基于地貌学角度来定义地貌形态结构的方法,利用有限个数的形态要素的空间组合和对比分析来获取特征地貌,并可以对各种特征地貌形态进行符合物理意义的改进。  相似文献   
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Abstract

A Digital Elevation Model (DEM) of Mt. Etna is presented; it has altimetric and planimetric resolution of 1 m and 5 m, respectively, and covers an area of about 120 km . This 3-D view of Mt. Etna allowed both recognition and location of the main morphostructural and volcano-tectonic features of the volcano. A slope map has been generated from the DEM; on the basis of slope distributions and surface textures, five acclivity domains have been recognized. The largest domain, south of the summit craters, reflects the occurrence of old plateau lavas, distinct from central volcanoes which built the present Etnean volcanic system. Interaction between the central volcanoes, with their summit calderas and failed slopes, produced the other recognised domains. Furthermore, newly identified relevant morphostructural lines are discussed. © Elsevier, Paris  相似文献   
6.
基于TM遥感图像解译和野外调研,分析了攀西地区大渡河、安宁河深切河谷地貌特征和断裂带构造变形特征,建立了安宁河断裂带晚新生代5阶段变形历史。研究表明,中新世晚期—上新世早期,安宁河断裂以挤压走滑活动为主;上新世晚期至早更新世时期,断裂以斜张走滑活动为主,活动强度较弱;早中更新世之间发生的元谋运动使昔格达组湖相地层褶皱变形;中晚更新世时期发生断陷作用,形成安宁河两堑夹—垒的构造格局;晚更新世—全新世时期又以左旋走滑活动为主。综合安宁河、大渡河河谷地貌和晚新生代地层记录和变形特征,提出了攀西高原晚新生代4阶段隆升模式:中新世早中期(12Ma之前)以缓慢隆升与区域夷平化作用为主,中新世晚期—上新世早期(12~3.4Ma)是高原快速隆升与河流强烈下切的时期,上新世晚期—早更新世(3.4~1.1Ma)为昔格达湖盆发育时期,中晚更新世—全新世(1.1Ma以来)是高原快速隆升与河谷阶地发育时期。最后指出,至上新世晚期(3.4Ma以前),攀西高原海拔高度可能超过了3000m。  相似文献   
7.
The Bransfield Basin is a narrow and elongated active rift basin located between the Antarctic Peninsula and the South Shetland Islands. The Bransfield Basin is composed of three small basins, and two of them, the Central and Eastern Bransfield Basins, were surveyed during a recent cruise (GEBRA 93). The full swath bathymetry coverage as well as the single-channel seismic reflection and magnetic profiles that have been acquired, help us to better understand the morphostructure and recent evolution of the Bransfield Basin. Six large volcanic edifices aligned with the basin axis stick out of the sedimented seafloor of the Central Bransfield Basin. In contrast, the Eastern Bransfield Basin is characterised by four deep troughs displaying a rhombic-shape, and small, scattered volcanic cones located in the southwestern half basin. Seamount volcanism plays an important role in the formation of new crust in the Bransfield Basin. The larger seamounts of the Central Bransfield Basin are located at the intersection of the two main orthogonal sets of faults (longitudinal ENE-WSW and transversal NNW-SSE). Morphological analysis of the seamounts indicates a multi-staged volcano-tectonic construction. The distribution and shape of these edifices suggests that both volcanism and extension are concentrated at the same preferential areas through time. This might be related to the fracturation style of the continental crust. The Central and Eastern Bransfield Basins are very different in morphostructure, volcanism, and sedimentary cover. The Central Bransfield Basin shows evidence of NW-SE extensional faulting and focused active MORB-volcanism interpreted as result of incipient seafloor spreading. The Eastern Bransfield Basin is still in a rifting stage, mainly dominated by a NW-SE extension and some left-lateral strike-slip component probably related to the South Scotia Ridge.J. Acosta, J. Baraza, P. Bart, A.M. Calafat, J.L. Casamor, M. De Batist, G. Ercilla, G. Francés, E. Ramos, J.L. Sanz, and A. Tassone.  相似文献   
8.
Using a new tool of seafloor characterisation (sonar images from FARA-SIGMA cruise; Needham et al., 1992), coupled with submersible observations (DIVA1 cruise) we compare, at different scales of observation, three contiguous segments of the Mid-Atlantic Ridge, South of the Azores Triple Junction, between 37° N and 38°30 N.The two northernmost segments (38°20 N and Menez-Gwen) show unusual morphological features for the MAR; the rift valley is absent and the present-day magmatism is focused on shallow axial volcanoes. On the third segment (Lucky Strike), the morphology is the one usually found on the MAR. On the Menez-Gwen and 38°20 N segments, volcanic constructional activity can obliterate, during periods of high magmatic supply, the morphology inherited from tectonic activity. The dive results constrain the recent evolution of each segment and show that a temporal variability in volcanic dynamics exists. On the three segments, outcrops of eruptive lavas alternate with large areas of explosive volcanic ejecta. This cycle in volcanic activity is influenced by changes in water depth, both spatially (i.e. between segments) and temporally (i.e. for the same segment through time).Each segment has known a specific history in its accretionary processes with a succession of tectonic and volcanic predominance and changes in its volcanic phases between volcanic ejecta and effusive dynamics.The hydrothermal activity is focused at the central part of each segment and is controlled by the presence of fresh lava and major tectonic features.  相似文献   
9.
The 400 km long Valencia Channel occupies the axis of the Valencia Trough in the Northwestern Mediterranean. Four different types of seismic reflection profiles were used to analyze the morphology and structure of the Valencia Channel with regard to the role played by both margins, Balearic and Iberian, of the Valencia Trough. From a detailed morphoseismic analysis of the Valencia Channel, its upper, middle, and lower courses can be characterized as follows: (1) in the upper course, tributaries are short and only slightly incised, with recent mass-transport deposits occurring on the adjacent continental slopes; (2) in the middle course, the channel deepens, and tributary valleys merge into it; and (3) the lower course begins after a sudden change in the direction of the channel, has a meandering path, is flanked by levees, and is fed by some valleys.During the Pliocene and Quaternary, at least four erosional and filling phases are observed in seismic profiles of the lower course of the Valencia Channel. The varying intensity of mass-transport processes and associated retrogressive slumping, which are related with fluctuations in sediment supply and relative sea-level changes, have played a major role in the formation, maintenance and deepening of the Valencia Channel. In addition to these sedimentary processes, a basement tectonic control and some morphostructural features affect the direction of the Valencia Channel locally.  相似文献   
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