摘要
根据分形理论和各板块的面积以及现代大陆各地块面积资料 ,分别进行了全球岩石圈板块和全球大陆地块自相似性特征尺度与频度关系的研究讨论。结果表明 ,现代全球岩石圈板块在特征线度r =30 0～ 180 0km的无标度空间范围内具有分形分布特征 ,其分维数D =0 72 ;现代全球大陆地块在特征线度r =30 0～ 150 0km的无标度空间范围内具有分形分布特征 ,其分维数D =1 16 ,比现代全球板块 0 72的分形值高出 6 1%。进一步讨论认为 :传统的“板块构造动力”应区分为岩石圈破裂形成板块动力的“板块构造动力Ⅰ”和板块水平运动驱动力的“板块构造动力Ⅱ”两个方面 ;全球板块总数为 18个左右、最小板块面积在 3× 10 5 km2 左右的板块分布 ,可能与板块的形成、演化有密切关系 ;原始岩石圈板块的分形分布 ,在地球构造演化过程中有一个降维演化趋势 ,其降维演化的速率约为 4 34× 10 -10 a-1;根据分维数反映分形客体复杂与不规则程度的物理意义 ,岩石圈破碎地块的降维演化意味着岩石圈地块的破碎状况及其分布 ,具有在总体上随时间演化而逐渐向简单、规则方向演化的趋势 ;原始岩石圈的破裂以及岩石圈破碎地块从古老大陆地块向现代板块的降维演化可能源于地球的膨胀 。
Based on the fractal theory and the area data of the global continental massifs,both of the characteristic yardstick of the modern global continental massifs and their frequency have been analyzed and discussed in this paper.The fractal structure of the global lithospheric massifs within the yardstick space of r =300～1800km possesses the character of fractal distribution,and it's fractal D is 0.72.The Global continental massif is of r =300～1500km,and it's fractal D is 1.16,which is larger than the present plate's for 61%.It is indicated that the traditional continental evolutional process may be divided into the broken lithospheric dynamics and the horizontal movement dynamics.The global continents massifs are divided into more than 18platelets with a size of 3×10 5km 2,which may be responsible for the formation and evolution of the continents.The velocity of the dropping fractal evolution is 4.34×10 -10 a -1 ,and the dropping fractal is related with the velocity of the Earth's expansion.According to physics,the fractal reflects the intricacy and abnormity of the fractal object.The evolution of the dropping fractal and that of the broken lithospheric massifs tends to become simple and to possess a regular direction with time.The Earth's expansion is the mechanism,which leads to the dropping fractal evolution of the global lithospheric massifs,and also to the increase of the Earth's surface area.At the same time,it changes the distribution of the global lithospheric massifs and forms the process of the global dropping fractal evolution.
出处
《地学前缘》
EI
CAS
CSCD
2000年第1期109-121,共13页
Earth Science Frontiers
基金
国土资源部中俄国际合作基金项目!(编号 :2 6 9)
关键词
板块构造
板块分形
陆块分形
降维演化
岩石圈
plate tectonics
plate fractal
fractal of continental massif
evolution of dropping fractal
tectonic dynamics
Earth's expansion
