FROM THE POLYCYCLICITY THEORY TO OPEN-AND-CLOSE TECTONICS

Professor Huang Jiqing (T. K. Huang) put forward the concept of polycy clic tectonic movement which was developed into the polycyclicity theo ry that is influential all over the world. This paper outlines the bas ics of this theory. The present author tries to distinguish between tw o kinds of polycyclic tectonic movements: in situ superimposition and recurrence in other places according to whether or not they recur at t he same place. Further study on the latter led to the concept of tecto nic migration. Tectonic migration is the vivid representation of the r ecurrence of polycyclic movements, an in-depth development of the poly cyclicity theory. Applying the plate tectonics theory to the practical geology of China, Huang set up the accordion movement model of plate movement, which has enriched plate tectonics theory and polycyclicity theory. Based on this pioneer's research, the present author has propo sed the concept of open-and-close tectonics, interrelating the polycyc licity theory, accordion movement, tectonic migration and plate tecton ics, and attempts to find a new way in the study of geotectonics. From the polycyclicity theory through the tectonic migration theory to ope n-and-close tectonics, one can trace the trajectory of the polycyclici ty theory and see its development, with the open-and-close tectonics ( O-C tectonics) being a milestone in the development of the polycyclici ty theory. Copyright (C) 1996 Published by Elsevier Science Ltd