STUDIES ON THE GENERAL DISTRIBUTION OF CRUSTAL THICKNESS AND CHARACTERISTICS OF CRUSTAL STRUCTURE UNDER THE ASIAN CONTINENT
Wang Qianshen, Wu Chuanzhen, Liu Hongchen and Wei Ying(Institute of Geophysics, Academia Sinica)
In this paper according to the data of Asian continental 1°×1° mean gravity field of Bouguer anomaly and a monolayer, homogenous, calculative crustal model, the total 10456 gravity data belonging to 131 gravity profiles have been calculated for determining the depth of Moho discontinuity. Obtained from this has been an outline map showing the distribution of Asian continental crustal thickness. Based on these results gained, the features of distribution of the crustal thickness and outline of crustal structure under the Asian continent have been analyzed and studied. Finally, this paper advances the principal characteristics of the Asian continental crust. There exist four vast areas of relatively minor variations in the crustal thickness, namely, northern, eastern southern and central areas of Asian crust; three great comprehensive steep (progressive) variational zones of crustal thickness, i. e. Pamir-Altai-Trans-Khingan complex steep variational zone, Trans-Khingan and Da Hinggan-Taihang-Wuling-Miaoling-Hengduan mountains progressively variational zone, and Zagros-Pamir-Himalayas steep variational zone; two complex convergent "node" of steep variational zones of crustal thickness, Pamirs "node" and Hengduan mountains "node"; and one Qinghai-Xizang crustal block with great thickness.