| 中国第四纪的构造事件与应力场 |
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| 引用本文： | 万天丰.中国第四纪的构造事件与应力场[J].第四纪研究,1994,14(1):48-55. |
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| 作者姓名： | 万天丰 |
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| 作者单位： | 中国地质大学 |
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| 摘 要： | 在早、中更新世之间(０．７３ＭａＢ．Ｐ．)我国存在一次重要的构造事件，由此第四纪便分属两个构造期：喜马拉雅期(２３．３—０．７３ＭａＢ．Ｐ．)和新构造期(０．７３Ｍａ以来)。在这两个时期内，具有截然不同的构造应力场、不同的形成机制、不同的构造变形方式、方向、不同的扩张或缩短速度、不同类型的火山喷发、不同方向和不同位置的火山喷发带，并且也造成完全不同的构造地貌特征。
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| 关 键 词： | 构造事件 应力场 构造－岩浆活动 构造地貌 |
TECTONIC EVENT AND STRESS FIELD OF QUATERNARY IN CHINA |
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| Institution: | China University of Geosciences, Beijing |
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| Abstract: | It can be found that there are unconformities between lower and middle Pleistocene (0.73 Ma B.P.) in many places over China, this is the main manifestation of tectonic event for Quaternary. According to the boundary for above event, the Quarternary period could belong to two tectonic stages: Himalayan stage (23.3 0.73 Ma B.P.) and Neotectonic stage (since 0.73 Ma B.P.).In these two stages, there existed extreme differences in tectonic stress fields,geodynamic mechanisms, styles and orientations of deformations, velocities of extension or shortening, volcanic types, orientations and positions of the volcanic zones,and the characteristics of tectonogeomorphology.In Himalayan stage, according to 427 mega-meso type flexural folds, the regional tectonic stress orientation can be determined and is characterized by the near north-south trending horizontal compression and near east-west trending horizontal extension with the rock deformations stronger on the borders of the plate and weaker within the plate. The average extensive velocity in east-west orientation for the intraplate of China is 0.33 cm/a. A series of near north-south orientated basic volcanic eruption zones and the four mega-steps in geomorphology are formed. The border extensive zone of eastern Asia was developed. The Himalayan stage is the main forming stage of landform, which provides the condition for the Yangtze and Yellow River to run through the whole drainage area.As to the tectonic orientation of Neotectonic stage, depending on the data of folding for Taiwan Strait and the fault plane solution of earthquakes for the whole China, the maximum principal compressive stress orientation could be determined:in northeast and north China it is ENE trending, in southern Shandong-Xi'an area it is near east-west orientation, in south China it is NW trending, from QinghaiXizang(Tibet) plateau to Inner Mongolia it is near NS to NE orientation. In this stage, rock deformations are relatively weak. The average velocities of extension and the slip for the active fault surface are 0.26-0.32 cm/a. The volcanic activity was rather limited. In addition to the development of the acid-intermediate volcanic eruption zone on the continental borders, the small scale basic volcanic eruption zone was formed Within the continent in the orientation nearly parallel to the recent maximum principal compressive stress. In the Neotectonic stage, the reformation for landform is rather weak. |
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