摘要
对中国东部沿海地区利用50年代至80年代的精密水准复测资料,在均衡基准下研究了近代地壳垂直运动。用速率面拟合法由计算机绘制了速率等值线图,并结合区域地质构造、古海岸变迁,分区讨论了东部沿海地区的近代地壳垂直运动特征。为研究海面变化对中国东部沿海地区的影响提供了依据。
From the 250000 km's precise releveling data obtained from 50's to 80's by using the so-called Vertial Crustal Movement Isostatic Datum, the vertical movement velocities at 1460 bench marks in the coastal area of eastern China are calculated. On the basis of these results, a velocity contour map of vertical crustal movement in the coastal area of eastern China has been compiled by using the velocity surface filing method and the map is first drawn with computer and plotter. Combined with the sea-level change along the coast of China under the same datum, the data provide a basis for studying sea-land relative movement.Combining with the regional geological structure, Quarternary marine bed and ancient se-lovel change, the regional geological tectonic background is synthetically analysed, moreover, the essential feature of recent vertial crus'al movement are studied. Preliminary study on the map indicates that the recent vertical crast al movement in the coastal land of eastern China has close relation to the geological tectonics and geomorphic units in this area.In general, the essential feature of vertical crustal movement in the coastal land of China are that the vertical movement is relatively strong, the deformation pattern is more complex and the regional change of uplift and subsidence is mainly controlled by the tectonic N-E orientation in the northern part. The vertical curtal movement is weak and gentle in the cen ral part and the change of uplift and subsidence is relatively low and the tectonic activity therefore is relatively weak. In the south area, the large scale regional block uplift and subsidence are evident but the intensity is no so strong in the most part of the area.Based on the vertical movement profile along the coastal area it can seen clearly the Obvious consistency with the tectonic-geomorphis features in the coast area. Based on the coastal vertical deformation study, the deformation pattern can be devided into two parts-the southern and northern parts with Hangzhou-Wenzhou line. as the boundary. The northern coastal line is mainly subsided (Shandong penin sula and Shanhaiguan area is uplifted in the subsiding background), including the plain in the lower Liaohe River, the North China plain and the Changjiang delta, etc. Inside the area, some uplift and subsidence regions are alternately distributed, that is consistent with the arrangement of the regional tectonic uplift and subsidence zones and an inherited motion is very obvious. In the southern part, of the coastal area is uplifted mainly, including the moun am and hilly land arranging along the coastal line, they are generally distributed in the same uplift zone in a larger extent, and have a good consistency with the recent vertical crustal movement represented by the modern geomorphology.
出处
《地质科学》
CAS
CSCD
北大核心
1993年第3期270-278,共9页
Chinese Journal of Geology(Scientia Geologica Sinica)
基金
国家自然科学基金9488007号大型项目
中国科学院87-45-03号重大项目联合资助课题
关键词
地壳
垂直运动
水准测量
海面变化
Vertical crustal movement, Leveling, Seavling Change, Isostatic datum
