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Seismic Velocity Structure and Composition of the Continental Crust of Eastern China
Author(s) -
Yang WANG,
Jiamin CAO,
Jieshou ZHU
Publication year - 2004
Publication title -
acta geologica sinica ‐ english edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.444
H-Index - 61
eISSN - 1755-6724
pISSN - 1000-9515
DOI - 10.1111/j.1755-6724.2004.tb00702.x
Subject(s) - crust , geology , longitude , tectonics , latitude , continental crust , china , seismology , upper crust , geodesy , geophysics , geography , archaeology
On the basis of a one‐by‐one latitude‐longitude grid three‐dimensional seismic velocity model, the crustal P‐wave velocity structure in eastern China (105–125°E and 18–41°N) is obtained, and a set of geotherms for each grid is established for P‐T correction on P‐wave velocities. The average depths of sub‐crustal layers and their average P‐wave velocities of 18 tectonic units in eastern China are exhibited. Our result presents a 32–34 km thick crust beneath eastern China, which is thinner than previous studies, with an average velocity of 6.54 km/s, corresponding to a 5 kg/m 3 variation in crustal mean density. The thicker upper but thinner middle and lower crust results in a lower average seismic velocity of eastern China. An intermediate crustal composition with a SiO 2 content of 59.7 wt% has been estimated. However, there exists a significant lateral variation in the crustal structures among the tectonic units of eastern China. The structure and composition features of some regions in eastern China indicate that extension has played an important role in the continental crust evolution of eastern China.