Fragments of oceanic plates that disappeared 2.7 billion years ago push forward the massive empirical evidence of plate tectonic theories by 200 million years

Original title: The Team of The University of Earth Discovers Fragments of Oceanic Plates That Disappeared 2.7 Billion Years Ago in North China (Introduction)

Pushing the large-scale empirical evidence of plate tectonic theory forward by 200 million years (theme)

Hubei Daily News (reporter Zhang Xin, correspondent Pang Weihong) on November 3, the reporter learned from the China University of Geosciences (Wuhan) that the university's Professor Tim Kosky team of the State Key Laboratory of Geological Processes and Mineral Resources published the latest scientific research results, taking the central orogenic belt in north China as the research object, pushing the large-scale empirical evidence of plate tectonic theory forward by 200 million years (forward to 2.7 billion years ago), providing the most direct evidence for the existence of large-scale horizontal plate tectonics in the early earth (Archean).

The theory of plate tectonics was born in the 1960s, and compared with the previous trough theory that emphasized vertical motion, plate tectonic dynamics emphasizes horizontal movement between plate lithospheres, which is generally considered to be the root cause of land and sea changes. But when it will start is a hot debate among geologists. During the horizontal displacement of oceanic plates and continental plates, the cold and heavy oceanic crust subducts under the relatively light continental crust and slowly disappears, and the land and land or island arcs collide and "meet", resulting in an proliferative orogenic belt. This orogenic belt is a direct product and evidence of plate tectonics.

Early in the birth of plate tectonic theory, the time point of the orogenic belt discovered by scientists was the Phanerozoic, that is, 570 million years ago to the present. In recent years, more and more evidence has pointed to the range from 4.5 billion years ago to 850 million years ago, and the more you push forward, the less and more difficult the evidence of large-scale plate tectonics is retained, which makes the start time of plate tectonics more confusing.

Twenty years ago, Tim Kosky and Peking University professor Li Jianghai found fragments of ocean plates that disappeared 2.5 billion years ago in the Zunhua region of north China, and before that, north China was regarded as a continental plate that had not been spliced and had long been stable for a long time. That discovery pushed forward the earliest substantial evidence of plate tectonics 2.5 billion years ago, causing strong debate in academic circles at home and abroad.

In 2009, the University introduced Professor Tim Koski, an internationally renowned expert in the field of plate tectonics. Over the past 12 years, he has led a research team to further find discriminatory evidence of land and sea changes in the deep mountains of Jianping in Liaoning, Zunhua-Xingtai in Hebei and Dengfeng in Henan, and to reveal and determine an arc-land collision hyperplasia orogenic belt that extends nearly 1,600 kilometers longitudinally from north to south and formed 2.5 billion years ago in North China.

Through further analysis of the orogenic belt, the team demonstrated that between 27 years ago and 2.5 billion years ago, the lateral tectonic displacement of the plate subduction reduced the crust at least 3560 km wide, until the arc land collision occurred 2.5 billion years ago, achieving the consolidation of plate boundaries, providing direct evidence for the existence of large-scale horizontal plate tectonics in the early Earth (Archean) period. The research results were published in the internationally important academic journal Nature Communications.

Wang Lu, a professor at the University of Earth and co-corresponding author of the paper, introduced that how the earth evolved from the magma sea that spread around the world in the early days to the habitable earth on which it depends today is the ultimate proposition for human beings to explore the mysteries of nature and the origin of life. Finding evidence, times, causes and locations of land and sea changes is important for understanding land evolution, the development and conservation of natural resources.