After nearly four years' efforts, a borehole depth of 5, 158 meters has been realized at the No. 1 well of Chinese Continental Scientific Drilling (CCSD) program in Maobei Village, Donghai County of east China's Jiangsu Province accompanied with a series of scientific achievements.
It signifies China's significant breakthrough in its exploration deep into the earth.
According to Wang Da, chief commander of the program, due to the block of hard rocks, mankind has very little knowledge of the inner part of the earth. Since the 1950s, scientific drilling was started with collection of fluid from core, debris and rock layer by means of drilling, and geophysical logging as well as long-term observation through equipment placed at the drill hole.
To date, the deepest drill hole in the world is the super deep drill hole at Kola, which reaches 12, 262 meters.
Chinese scientists started on June 25, 2001drilling at the Sulu ultra-high-pressure metamorphic belt in east China, which is a border of converging plates of global implication. With China's self-developed technologies, a drilling depth of 5, 158 meters into the hard crystalline rock was realized, and precious samples of core deep at 5, 118.2 meters were acquired.
It is the deepest drilling both in China's history and among the over 20 ongoing projects of the International Continental Scientific Drilling Program (ICDP).
Through the scientific drilling this time, Chinese scientists made a number of innovative achievements as they uncovered the substance composition deep at the convergent boundary of plates and the composition deep in the ultra-high pressure metamorphic area; proved the existence of magnificent geological event in which plate with a huge amount of substance rushed to deep mantle, and the significant splitting seven to eight million years ago; marked typical geophysics field in crystalline-rock area; put forward new model of "deep subduction-exhumation".
China will establish a long-term observation station at main drill hole of the No. 1 well for further information on inside the earth.
(People's Daily April 19, 2005)
