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21.
J. Haas P. Mioč J. Pamić B. Tomljenović P. Árkai A. Bérczi-Makk B. Koroknai S. Kovács E. Rálisch-Felgenhauer 《International Journal of Earth Sciences》2000,89(2):377-389
Due to the political boundaries between the Central European countries, on one hand, and the thick Tertiary cover in the
Pannonian Basin, on the other, the eastward continuation of the Alpine and Dinaridic units has been ambiguous and poorly documented.
Based on comparative analyses, the aim of the present paper is to define the pre-Tertiary structural units in the junction
area of the Alpine, Dinaridic, and Pannonian regions, in the SW part of the Pannonian Basin, and to draw conclusions on the
continuation of the Alpine and Dinaridic units. According to diagnostic characteristics of the Periadriatic Lineament system,
the Balaton Lineament system may be considered as its direct eastern continuation. North of the Periadriatic–Balaton Lineament
system, the Transdanubian Range Unit, due to its pre-Tertiary paleogeographic setting, shows mainly South Alpine facies relations;
however, its present structural position is identical to that of the Upper Austroalpine nappes. Between the Periadriatic–Balaton
and Zagreb–Zemplin Lineament systems heterogeneous structural units are juxtaposed, forming the Sava Composite Unit. In the
northern part of this composite unit non-metamorphosed nappes occur which can be considered the eastern continuation of the
South Alpine units. These nappes are overthrust onto Internal Dinaridic units in the Tertiary. The Zagreb–Zemplin (Mid-Hungarian)
Lineament separates the Sava Unit from the Tisza Unit showing close affinity to the Tethyan margin of the Eurasian plate during
the early stage of the Alpine evolution.
Received: 1 June 1999 / Accepted: 14 March 2000 相似文献
22.
选取黑龙江、 吉林、 辽宁、 内蒙古区域地震台网, 以及NECESSArray流动台阵记录的223个远震事件的波形资料, 采用多道互相关方法得到了22569个P波相对走时数据, 并计算了相应的走时灵敏度核, 应用有限频率层析成像反演得到中国东北地区上地幔600 km以上的P波三维速度结构模型, 利用检测板评估了反演结果的分辨率。 结果表明, 松辽盆地下方80~200 km的深度上呈主体的低速异常, 与这一地区上地幔浅部的高地温值和低密度的特征相互对应, 可能暗示了部分熔融的地幔。 南北重力梯度带两侧的速度结构明显不同, 这一差异可以延伸到200 km以下, 表明在中国东北地区南北重力梯度带有可能是一条上地幔内部结构的变化带, 或是深部结构的分界线。 长白山火山区下呈大范围的低速异常, 并可从上地幔浅部延伸到地幔转换带中, 推测此低速异常可能反映了地幔转换带内上涌的热物质, 上涌的原因则主要是受到太平洋板块俯冲运动的作用。 相似文献
23.
应用多种遥感图象对吉林省南部的通化地区、浑江地区综合解译后发现,此区的线性构造以北东向呈连续带状、近东西向为断续带状、北西向略具分带性为特征,环状构造多在不同方向线状构造带交汇部位成群出现。区内众多的内生金属矿床(点)多分布在不同方向线性构造带交汇部位的环状构造群内,根据这一关系,预测遥感影象类同的复兴屯等四个地区为找寻内生金属矿产的最佳远景区。 相似文献
24.
本文采用图像平滑、边缘跟踪、霍夫变换、逆霍夫变换等综合图像处理技术，从卫星ＴＭ图像中提取线性体信息。在霍夫变换后的累加器阵列中采用局部最大值选择，逆霍夫变换后采用剖面分析等人一机交互处理方法，结合遥感地质学家的图像判读经验，提高了线性体信息自动提取的精度。 相似文献
25.
The Arthur Lineament of northwestern Tasmania is a Cambrian (510 ± 10 Ma) high‐strain metamorphic belt. In the south it is composed of metasedimentary and mafic meta‐igneous lithologies of the ‘eastern’ Ahrberg Group, Bowry Formation and a high‐strain part of the Oonah Formation. Regionally, the lineament separates the Rocky Cape Group correlates and ‘western’ Ahrberg Group to its west from the relatively low‐strain parts of the Oonah Formation, and the correlated Burnie Formation, to its east. Early folding and thrusting caused emplacement of the allochthonous Bowry Formation, which is interpreted to occur as a fault‐bound slice, towards the eastern margin of the parautochthonous ‘eastern’ Ahrberg Group metasediments. The early stages of formation of the Arthur Lineament involved two folding events. The first deformation (CaD1) produced a schistose axial‐planar fabric and isoclinal folds synchronous with thrusting. The second deformation (CaD2) produced a coarser schistosity and tight to isoclinal folds. South‐plunging, north‐south stretching lineations, top to the south shear sense indicators, and south‐verging, downward‐facing folds in the Arthur Lineament suggest south‐directed transport. CaF1 and CaF2 were rotated to a north‐south trend in zones of high strain during the CaD2 event. CaD3, later in the Cambrian, folded the earlier foliations in the Arthur Lineament and produced west‐dipping steep thrusts, creating the linear expression of the structure. 相似文献
26.
Understanding the orientation distribution of structural discontinuities using the limited information afforded by their trace in outcrop has considerable application, with such analysis often providing the basis for geological modelling. However, eigen analysis of 3D structural lineaments mapped at decimetre to regional scales indicates that discontinuity best fit plane estimates from such datasets tend to be unreliable. Here, the relationship between digitised lineament vertex geometry (coplanarity/collinearity) and the reliability of their estimated best fitting plane is investigated using Monte Carlo experiments. Lineaments are modelled as the intersection curve between two orthonormally oriented fractional Brownian surfaces representing the outcrop and discontinuity plane. Commensurate to increasing lineament vertex collinearity (K), systematic decay in estimated pole vector precision is observed from these experiments. Pole vector distributions are circumferentially constrained around the axis of rotation set by the end nodes of the synthetic lineaments, reducing the rotational degrees of freedom of the vertex set from three to one. Vectors on the unit circle formed perpendicular to this arbitrary axis of rotation conform to von Mises (circular normal) distributions tending towards uniform at extreme values of K. This latter observation suggests that whilst intrinsically unreliable, confidence limits can be placed upon orientation estimates from 3D structural lineaments digitised from remotely sensed data. A probabilistic framework is introduced which draws upon the statistical constraints obtained from our experiments to provide robust best fit plane estimates from digitised 3D structural lineaments. 相似文献
27.
Swath bathymetric, sonar imagery and seismic reflection data collected during the SOPACMAPS cruise Leg 3 over segments of the Vitiaz Trench Lineament and adjacent areas provide new insights on the geometry and the stuctural evolution of this seismically inactive lineament. The Vitiaz Trench Lineament, although largely unknown, is one of the most important tectonic feature in the SW Pacific because it separates the Cretaceous crust of the Pacific Plate to the north from the Cenozoic lithosphere of the North Fiji and Lau Basins to the south. The lineament is considered to be the convergent plate boundary between the Pacific and Australian Plates during midde to late Tertiary time when the Vitiaz Arc was a continuous east-facing are from the Tonga to the Solomon Islands before the development of the North Fiji and Lau Basins. Progressive reversal and cessation of subduction from west to east in the Late Miocene-Lower Plioene have been also proposed. However, precise structures and age of initiation and cessation of deformation along the Vitiaz Trench Lineament are unknown.The lineament consists of the Vitiaz Trench and three discontinuous and elongated troughs (Alexa, Rotuma and Horne Troughs) which connect the Vitiaz Trench to the northern end of the Tonga Trench. Our survey of the Alexa and Rotuma Troughs reveals that the lineament is composed of a series of WNW-ESE and ENE-WSW trending segments in front of large volcanic massifs belonging to the Melanesian Border Plateau, a WNW trending volcanic belt of seamounts and ridges on Pacific crust. The Plateau and Pacific plate lying immediately north of the lineament have been affected by intense normal faulting, collapse, and volcanism as evidenced by a series of tilted blocks, grabens, horsts and ridges trending N 120° to N100° and N60°–70°. This tectonism includes several normal faulting episodes, the latest being very recent and possibly still active. The trend of the fault scarps and volcanic ridges parallels the different segments of the Vitiaz Trench Lineament, suggesting that tectonics and volcanism are related to crustal motion along the lineament.Although the superficial observed features are mainly extensional, they are interpreted as the result of shortening along the Vitiaz Trench Lineament. The fabric north of the lineament would result from subduction-induced normal faulting on the outer wall of the trench and the zig-zag geometry of the Vitiaz Trench Lineament might be due to collision of large volcanic edifices of the Melanesian Border Plateau with the trench, provoking trench segmentation along left-lateral ENE-WSW trending transform zones. The newly acquired bathymetric and seismic data suggest that crustal motion (tectonism associated with volcanism) continued up to recent times along the Vitiaz Trench Lineament and was active during the development of the North Fiji Basin. 相似文献
28.
Ute Weckmann Oliver RitterVolker Haak 《Physics of the Earth and Planetary Interiors》2003,138(2):91-112
Magnetotelluric (MT) observations at some sites in the vicinity of the Waterberg Fault/Omaruru Lineament (WF/OL), a major tectono-stratigraphic zone boundary in the Central Zone of the Damara Belt, show evidence for strong three-dimensional (3D) effects. We observe very high skew values, phases over 90°, and a strong correlation of parallel components of the electric and magnetic fields at long periods. Because of the dense site spacing and good spatial coverage, we can positively attribute these effects to local geology and are able to resolve structural detail within the WF/OL. Mapping LaTorraca’s electric characteristic vectors in form of ellipses proved particularly useful in identifying key elements of the conductivity structure for subsequent modelling. 3D and 2D anisotropic modelling can reproduce most of the observed 3D effects. The conductivity anomalies revealed in the area are: (i) a conductive ring structure in the shallow crust along the northern part of the profile; (ii) an anisotropic region in the upper crust with high conductivity parallel to the WF/OL; (iii) anisotropy in the lower crust with a different but undetermined strike direction; and (iv) a shallow elongated conductor sub-normal to the WF/OL. Modelling studies further suggest that the (anisotropic) fault zone is approximately 10 km wide and may reach down to a depth of 14 km or more. 相似文献
29.
The age and the southern continuation of the Rhenish Lineament, and its relation to the Bressegraben has been an elusive problem for a long time. Sedimentological data are presented in this paper, which show that a major fault zone associated with the Rhenish Lineament extends southwards underneath the Jura Mountains of northern Switzerland. Mesozoic facies boundaries occur along this lineament and indicate that the Tertiary Upper Rhinegraben may be an ancient inherited structure, which was repeatedly reactivated during Mesozoic time. While reactivated Paleozoic faults seated in the basement are now known to play an important role in defining east–west trending facies boundaries and depocenters, north–south facies boundaries were attributed to autocyclic effects. This north–south component found in facies boundaries is now attributed to subsidence variations, which took place along the Rhenish Lineament. To distinguish increased local subsidence from eustatic sea level rise (i.e. development of accommodation space) it is necessary to reinterpret the sedimentary record accordingly. This study demonstrates that some sedimentary facies boundaries follow the Rhenish Lineament over the Paleozoic basins of northern Switzerland into the Bressegraben, thereby indicating an ancient structure, which had been reactivated during Mesozoic time. Sedimentological analysis shows that there is a relationship between facies boundaries, isopach anomalies, and basement structure. 相似文献