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### 黄土高原0.8 Ma以来地面抬升的时空特征研究

1. 1. 安徽师范大学地理系, 安徽 芜湖 241000
2. 安徽自然灾害过程与防控研究省级实验室, 安徽 芜湖 241000
3. 兰州大学地理系, 甘肃 兰州 730000
4. 云南师范大学地理系, 云南 昆明 650000
• 收稿日期:2011-12-12 修回日期:2012-05-10 出版日期:2012-09-20 发布日期:2012-09-20
• 作者简介:

作者简介：胡春生（1979-）,男,安徽无为人,讲师,主要研究方向为资源与环境。E-mail：huchsh03@163.com

• 基金资助:
安徽省自然地理学重点学科科研团队项目（asdgl0903）、国家自然科学基金（40471016）资助

### The Spatial and Temporal Features of Surface Uplift in Loess Plateau Since 0.8 Ma

Chun-sheng HU1,2(), Bao-tian PAN3, Huai SU4

1. 1.Department of Geography, Anhui Normal University, Wuhu, Anhui 241000, China
2.Anhui Key Laboratory of Natural Disaster Process and Preventing and Controlling, Wuhu, Anhui 241000, China
3.Department of Geography, Lanzhou University, Lanzhou, Gansu 730000, China
4.Department of Geography, Yunnan Normal University, Kunming, Yunnan 650000,China
• Received:2011-12-12 Revised:2012-05-10 Online:2012-09-20 Published:2012-09-20

Abstract:

The river terrace is one of the direct geomorphic evidences of the surface uplift. By analyzing the characteristics of the Yellow River terraces in Loess Plateau, it is presented that the terraces are mainly tectonic genesis, and formed after the Yellow River reached a quasi-equilibrium state. It is reasonable to use the Yellow River terraces for representing the surface uplift of the Loess Plateau. In the Lanzhou Basin, two fourth terraces of the Yellow River are selected as the study sections, namely the Zaoshugou terrace and the Wuyishan terrace. At the Zaoshugou terrace, the altitude of gravel stratum is 80 m higher than the river level. The top of the gravel stratum is overlain by at least 64 m eolian loess, and the paleosol S8 is at the bottom of the eolian loess. At the Wuyishan terrace, the altitude of gravel stratum is 140 m higher than the river level. The top of the gravel stratum is overlain by at least 100 m eolian loess, and the paleosol S8 is at the bottom of the eolian loess. The optically stimulated luminescence (OSL) dating result indicates that the age of the upper part of paleosol S1 at the Zaoshugou terrace is 70.4±7.6 ka. The results of paleomagnetic dating, optically stimulated luminescence dating and loess-paleosol sequence matching indicate that the two terraces have the same age, and both were formed at about 0.865Ma. Therefore this paper advances that there is the Yellow River terraces at 0.8Ma in the Lanzhou Basin, and the fourth terrace of the Yellow River may be a geomorphic response to the event of the surface uplift at 0.8Ma around the Qinghai-Tibetan Plateau. According to the research on the Yellow River terraces at 0.8Ma in the Loess Plateau and the correlative literature, this paper verifies that there was a large-scale surface uplift at about 0.8Ma in the Loess Plateau, and the surface uplift resulted in river incision and terrace formation. Lanzhou, Heishan Canyon, Shanxi-Shaanxi Canyon and Sanmenxia were also selected as the typical research areas in the Loess Plateau,and obvious spatial and temporal features of the surface uplift of the Loess Plateau since 0.8Ma was discovered, basing on the characteristic analysis of the sequences of the Yellow River terraces at this four sites. The rates of surface uplift are calculated by the rates of river incision and the amounts of surface uplift are calculated by the depth of river incision (height above river). The spatial feature is that the surface uplift of the western Loess Plateau is more intense than that of the eastern Loess Plateau, and the temporal feature is that the uplift speeds up gradually, especially since the late Pleistocene. This paper also proposes that the surface uplift of the Loess Plateau since 0.8 Ma is related to the surface uplift of the Qinghai-Xizang Plateau.

• P931