ON THE VERTICAL GROWTH OF THE EARTH’S CRUST IN THE EAST ASIA OUTSKIRTS AND ITS FLOODING BY THE WORLD OCEAN SIX THOUSAND YEARS AGO

详细

The relevance of the study is determined by the need of considering the earth’s crust in the East Asia outskirts, as  there are various contradictory judgments on its origin. The purpose of the work is to characterize the geological structure of the eastern margin of Asia, supplemented with new data. To solve the problem, it is used numerous geological data and seismic sections of the territory, obtained by means of its detailed studies in the twentieth century, and new data.  It is established that the eastern margin of Asia has a three-layered continental structure. Its active vertical geological development took place in the Precambrian (4.5–1.7 billion years ago), when the ancient crystalline foundation was created, partly in the Paleozoic, and most powerfully in the Mesozoic-Cenozoic time, when certain parts of the territory underwent several tectonic-magmatic cycles. During the Neocene-Quaternary period, there intensified vertical tectonic movements, volcanism and seismicity. Six thousand years ago, significant flat parts of the territory were covered by sea waters due to the increase in the level of the World Ocean, with the formation of large grabens in the Arctic and the Asia outskirts. Therefore, there appeared a wide shallow shelf and separate deep seas (3–7 km). In addition to well-established facts on the structure of the Earth's crust, there are also the discussion ideas based on plate tectonics and paleomagnetism –movements of individual tectonic blocks and even individual continents from south to north, by a distance of up to 2 thousand kilometers, and the oceanic crust immersion under the outskirts of Asia.