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| 地带性与非地带性夷平面* | |
| 引用本文： | 张信宝,周力平,汪阳春,吴积善,贺秀斌,齐永青.地带性与非地带性夷平面*[J].第四纪研究,2007,27(1):93-99. |
| 作者姓名： | 张信宝 周力平 汪阳春 吴积善 贺秀斌 齐永青 |
| 作者单位： | 1. 中国科学院水利部成都山地灾害与环境研究所,成都,610041;中国科学院地球环境研究所黄土与第四纪地质国家重点实验室,西安,710075 2. 北京大学城市与环境学系,北京,100871 3. 中国科学院水利部成都山地灾害与环境研究所,成都,610041 |
| 基金项目： | 中国科学院知识创新工程项目 , 国家自然科学基金 , 国家重点基础研究发展计划(973计划) |
| 摘 要： | 夷平面是指由剥蚀和夷平作用所产生的,以截面形式横切所有在年龄上先于它的地层和构造的一种平缓地形。前人普遍认为,夷平面是在构造相对稳定条件下经过长期外营力作用形成的一个接近基准面的平坦地形,是地貌长期演化的终极产物。 流水侵蚀是夷平面形成的动力学基础。"夷平面"一直是解释新生代以来大的构造格局和地貌演化的重要理论依据,如我国青藏高原隆升的研究。 基于气候地貌学原理,文章提出了寒冻夷平面和干旱夷平面的概念;从坡地演化过程理论模型入手,探讨了寒冻、干旱夷平面和流水夷平面的形成机理;提出有别于传统"构造侵蚀旋迴"理论的"构造隆升和地面剥夷动态平衡"的气候夷平地貌假说;此外,还简要分析了这三类夷平面的全球分布规律。 |
| 关 键 词： | 寒冻 干旱 流水 夷平面 地带性 非地带性 |
| 文章编号： | 1001-7410（2007）01-93-07 |
| 收稿时间： | 2006-01-05 |
| 修稿时间： | 2006-06-06 |
ZONAL AND NON-ZONAL PLANATION SURFACES |
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| Zhang Xinbao,Zhou Liping,Wang Yangchun,Wu Jishan,He Xiubin,Qi Yongqing.ZONAL AND NON-ZONAL PLANATION SURFACES[J].Quaternary Sciences,2007,27(1):93-99. | |
| Authors: | Zhang Xinbao Zhou Liping Wang Yangchun Wu Jishan He Xiubin Qi Yongqing |
| Institution: | (Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu610041|State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an710075|Department of Geography, Peking University, Beijing100871 |
| Abstract: | Planation surfaces are kind of flat or gentle landforms, which are products of denudation and planation processes. The surface cuts cross all strata and tectonics, which are older than formation of the surface. By classical theory of "tectonics-erosion cycles", planation surfaces are the final products of geomorphologic evolution after long-term exogenic processes under stable tectonic conditions. Fluvial erosion is the basic mechanics of the surface formation and the surface elevations are related to erosion base levels. The geomorphologic evolution theory is corresponding to classical geological theory of "platform-geosyncline". Both of the two theories were formed at the end of the 19th Century along with the famous Darwin Theory on biological evolution. However, as the "platform-geosyncline" theory has been replaced by the "plate tectonics" theory since the 1960s, the geomorphologic theory of "tectonics-erosion cycles" which has been used for interpreting large-scale tectonic structures and geomorphologic evolution in Cenozoic Era, for example, the uplifting processes of the Tibetan Plateau in China thus loses its theoretic basis. Based on climate geomorphologic principles, a hypothesis on the formation of zonal and non-zonal planation surfaces is proposed in this paper. The zonal planation surfaces include frigid and arid planation surfaces while the non-zonal ones include only fluvial planation surfaces. Frigid planation surfaces are formed by freezing-thawing erosion of soil creeping or earth flows in periglacial regions. The surfaces are distributed in high plateaus of the low or middle latitude regions, for example, the Tibetan Plateau, and in lowlands of the high latitude regions in the world. Arid planation surfaces are formed by rain splashing erosion in semiarid and arid regions. The arid planation surfaces are very distinguishing in the tropical and subtropical Savanna regions, for examples, the Brazil and the Guyana Plateaus in South America, the East African Plateau in Africa, and the Deccan Plateau of India in Asia, and are also distributed in temporal grass land regions. Fluvial planation surfaces are formed by fluvial erosion and distributed in various climate zones in the world.It is obvious that previous interpretation of geomorphologic evolution history in some regions by the classical "tectonics-erosion cycles" theory needs to be reinterpreted, for example, the uplifting processes of the Tibetan Plateau in China. A hypothesis of "dynamic equilibrium between tectonic uplifting and ground denudation" is proposed for interpreting the geomorphologic evolution history of the Tibetan Plateau. The plateau may be uplifted to the elevation of periglacial zone at a certain geological stage in the Cenozoic Era. Since then on the ground of the plateau have been suffered from freezing-thawing erosion of soil creeping and earth flows. Original landforms of the plateau may be flat planation surfaces or steep dissected mountains before the uplifting, and the present gentle hilly plateau surfaces were formed after it reached periglacial zone elevations. It is suggested that the tectonic uplifting rates have balanced the denudation rates and the plateau surface elevations have had no significant changes in the plateau for long. |
| Keywords: | frigid arid fluvial planation surfaces zonal non-zonal |
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