长江源区新构造运动及其生态环境效应   总被引：2，自引：0，他引：2  

贾小龙  赵洪菊  张森琦  辛元红  张启兴 《高原地震》2008,20(2):34-40

基于长江源区生态环境地质调查的大量实际资料及调查成果,经分析研究发现,长江源区早更新世处于走滑拉分运动的大陆动力学背景,在整体隆升中,形成走滑拉分盆地且分割盆地的断块山、湖泊广布;中更新世反转为挤压隆升,在整体抬升中迎来了新构造期最大冰期,湖泊萎缩;晚更新世－全新世过渡为整体走滑-挤压收缩,经历了动荡的隆升过程,湖泊响应明显。近代,特别是20世纪70年代以来,新构造活化与寒冻风化岩屑坡扩大、沙漠化蔓延、湖泊与沼泽湿地萎缩、区域地下水位下降、生态环境日益恶化等关系密切。因此,新构造驱动在长江源区生态环境恶化中起主导作用,而其他因素则起到促进与加速作用。  相似文献   

RE-COGNITION OF THE NEOTECTONICS AND ACTIVITIES OF THE YINGKOU-WEIFANG FAULT ZONE          下载免费PDF全文

GAO Zhan-wu  XU Jie  ZHAO Tie-hu  ZHANG Jin  JI Feng-ju  ZHOU Ben-gang 《地震地质》2017,39(1):43-53

The Yingkou-Weifang fault zone (YWFZ) is the part of the Tanlu fault zone across the Bohai Sea, and is also an important part of the tectonics of the eastern Bohai Bay Basin. Many studies have been carried out on the neo-tectonics and activities of the YWFZ in recent years. In this paper, the neo-tectonics and activities of the YWFZ, and other related issues were studied again, based on our previous work and results of other researchers. The neo-tectonic movement in the Bohai Sea area began in the late Miocene (12~10Ma BP), which originated from the local crust horizontal movement, the tectonic stress field is characterized by NEE-SWW and near E-W horizontal compression. The neo-tectonics of the YWFZ is represented mainly by Neogene-Quaternary deformation, due to rejuvenation of Paleogene faults. Many faults have developed. The neo-tectonics and activities of YWFZ have characteristics of segmentation and weakening, because of the development of the NE-trending Northwest Miao Island-the Yellow River Estuary fault zone, which crosses the YWFZ. Earthquakes in the east of Bohai Sea are distributed along the Northwest Miao Island-the Yellow River Estuary fault zone, only few and small earthquakes along the Liaodong Bay and the Laizhou Bay section of the YWFZ. We made a preliminary analysis of the mechanics for this phenomenon.  相似文献   

郯庐断裂带中段第四纪活动及其分段特征   总被引：30，自引：4，他引：30       下载免费PDF全文

施炜  张岳桥  董树文 《地球学报》2003,24(1):11-18

郯庐断裂带是中国东部一条岩石圈尺度的构造不连续带。位于江苏和山东培内的郯庐断裂带中段，在新构造运动时期强烈右旋走滑复活，形成地貌形迹显著的走滑活动断裂带。笔者在断层活动形迹的野外调查和观测的基础上，结合TM遥感影像特征解译和地震震源机制解资料，分析了郯庐断裂中段第四纪活动的分段行为特征。位于嘉山－潍坊之间的郯庐断裂带中段可以进一步划分为3段，北段安丘－茅埠亚段，中段汪湖－宿迁亚段，南段宿迁－嘉山亚段，这三段可能分别是独立的地震破裂段。观测表明，新构造变形主要集中在宿迁以北的中、北段，是历史强震的发生段，而南段变形相对较弱，嘉山以南安徽境内郯庐断裂新构造变形更弱。郯庐断裂带新构造走滑变形的走向分段行为是华北地区不同块体新构造运动位移调节的结果。  相似文献   

Response of drainage systems to Neogene evolution of the Jura fold-thrust belt and Upper Rhine Graben   总被引：1，自引：0，他引：1  

Peter A. Ziegler  Marielle Fraefel 《Swiss Journal of Geoscience》2009,102(1):57-75

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Uplift and active tectonics of southern Albania inferred from incision of alluvial terraces   总被引：2，自引：0，他引：2  

J. Carcaillet  J.L. Mugnier  R. Koi  F. Jouanne 《Quaternary Research》2009,71(3):465-476

In Albania, the Osum and Vjoje rivers cross the active graben system and the active frontal thrust system of the Albanides. The effects of climatic and geodynamic forcing on the development of these two rivers were investigated by the means of field mapping, topographic surveying and absolute exposure-age dating. We established the chronology of terraces abandonment from the compilation of new dating (¹⁴C and in situ produced ¹⁰Be) and previously published data. We identified nine fluvial terraces units developed since Marine Isotope Stage 6 up to historic times. From this reconstituted history, we quantified the vertical uplift on a time scale shorter than the glacial climatic cycle. Regional bulging produces an overall increase of the incision rate from the west to the east that reaches a maximum value of 2.8 m/ka in the hinterland. Local pulses of incision are generated by activation of normal faults. The most active faults have a SW–NE trend and a vertical slip rate ranging from 1.8 to 2.2 m/ka. This study outlines the geodynamic control in the development of rivers flowing through the Albanides on the scale of 10³–10⁵ka.  相似文献   

Triangulation-to-GPS and GPS-to-GPS geodesy in Trinidad, West Indies: Neotectonics, seismic risk, and geologic implications     

J.C. Weber  J. Saleh  S. Balkaransingh  T. DixonW. Ambeh  T. LeongA. Rodriguez  K. Miller 《Marine and Petroleum Geology》2011,28(1):200-211

We estimated horizontal velocities at 25 sites first surveyed in a 1901-1903 British Ordnance Survey triangulation and then resurveyed with GPS in 1994-1995 to identify Trinidad's principal active on-land faults, quantify fault-slip-rates, and test for elastic locking. Our best-fit single-fault elastic dislocation model put 12 ± 3 mm/yr of dextral strike-slip on the Central Range Fault (1-2 km locking depth), an apparently aseismic active fault. The estimated motions also showed statistically insignificant horizontal motion (2.2 ± 1.8 mm/yr of right-slip; 2.7 ± 2.0 mm/yr of N-S shortening) on the eastward on-strike extension of the El Pilar Fault, known to be the active transform fault in Venezuela. Repeat GPS measurements made between 1994 and 2005 at two sites spanning the island north to south showed a 14 ± 3 mm/yr eastward (plate-motion-parallel) dextral velocity differential, consistent with our best-fit historic (1901-1995) fault-slip-rate. Paleoseismology trenching demonstrates that the Central Range Fault cuts <5000-year-old sediment and is capped by ∼550-year-old sediment, suggesting that it may be locked and may have ruptured at least once during this time interval. About ∼5 mm/yr of slip could be taken up on the Los Bajos Fault and additional faults in the offshore south of Trinidad. The existing 1901-1995 and 1994-2005 geodetic data alone cannot resolve whether the Central Range Fault is essentially creeping (≤1-2 km locking depth) or locked to a more standard depth of 10 km.  相似文献   

新构造学研究新进展     

Chang Peixing  Chen Huixin 《地球科学与环境学报》1997,(1)

本文简单回顾了新构造研究历史，将其大致分为三个阶段：萌芽阶段，定性描述研究阶段和定性一半定量研究阶段．最后，重点讨论了该学科在基础理论和实际应用上的新成就．  相似文献   

Under-representation of faults on geological maps of the London region: reasons,consequences and solutions     

D.T. Aldiss 《Proceedings of the Geologists' Association. Geologists' Association》2013

London lies mainly within an area of long-term tectonic stability known as the London Platform. This is characterised by relatively thin Cretaceous and Palaeogene sequences overlying Palaeozoic basement at shallow depths, less seismic activity than surrounding areas and, according to published geological maps, little faulting.  相似文献   

The Servita Fault, Eastern Cordillera, Colombia: an Active Thrust Able to Produce an M > 7.0 Earthquake very near to Bogotá D.C.     

GERMáN Chicangan  CARLOS Vargas  ANDREAS Kammer 《《地质学报》英文版》2013,87(Z1):348-350

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Tectonic and liquefaction structures in the Loreto basin,Baja California (Mexico) : synsedimentary deformation along a fossil fault plane     

Andrea Zanchi 《Geodinamica Acta》2013,26(3):187-201

Abstract

Complex fault assemblages associated to liquefaction structures have been analyzed in a Pliocene basin located along the Gulf of California. The studied outcrop shows a fossil fault plane formed ill soft flat lying sediments. The liquefaction and fluidification structures have been recognized in voleaniclastic layers deposited ill a lagoonal environment and are potentially related to seismic wave shaking and to successive dewatering along fractures. This strati-graphic record is explained by the progressive development of a seismic fault zone, related to the transtensional regime still active in the Gulf. The present analysis can he considered as an useful case study for the reconnaissance of the different types of structures formed during synsedimentary deformation in hydroplastic conditions.  相似文献