the transition of individual areas of the earth’s crust to a more mobile state caused by an increase in the intensity of vertical movement of the earth’s crust.
Ordinarily, tectonic activation signifies the changing of platforms into highlands (activated platforms or epiplatform orogenic zones). Tectonic activation is most characteristic of the neotectonic stage of development of the earth’s crust, a stage which occurred simultaneously with the orogeny in the Alpine geosynclines. An example of tectonic activation would be the rise of mountainous zones on the site of the Asiatic platforms with a Precambrian and Paleozoic basement (for example, in the Tien-Shan and in the Baikal area).
Areas of tectonic activation are characterized by an increased thickness of the earth’s crust (chiefly due to the basalt layer), increased seismicity, manifestations of basalt vol-canism, and the presence of rifts (the Baikal system and the East African one). In the opinion of a number of researchers, tectonic activation has been tentatively linked to the warming up of the earth’s upper mantle and to the partial fusing of its matter.
REFERENCEKhain, V. E. Obshchaia geotektonika. Moscow, 1964.
V. E. KHAIN