Structural control of the Gagua “Wedge” Zone east of Taiwan Island on the southern Okinawa Trough  

作　　者：ZHENG Yanpeng1,2,3, LIU Baohua2,3, WU Jinlong2, LIANG Ruicai2,3, LIU Chenguang2,3 & ZHANG Zhengmin1 1. Marine Geology College, Ocean University of China, Qingdao 266003, China 2. First Institute of Oceanography, State Oceanic Administration, Qingdao 266061, China 3. Key Laboratory of Marine Sedimentology and Environmental Geology, State Oceanic Administration, Qingdao 266061, China 

出　　处：《Science China Earth Sciences》2005年第8期1165-1174,共10页中国科学（地球科学英文版）

摘　　要：Based on compositive analysis and interpretation of the observed and historical data, the geophysical field characters and structural properties of the Gagua “Wedge” Zone of the sea area east of Taiwan Island and the primary tectonic stress direction and its variabilities of backarc spreading in the southern Okinawa Trough are studied. It is concluded from the study results that the Gagua “Wedge” Zone is structurally consistent with the Gagua ridge and two fault basins on both sides of the Gagua ridge, and adjusts the moving direction and distance of the western Philippine Sea plate to make the northwestward motion of the plate on its east side change to the northward subduction of the plate on its west side so that the primary tectonic stress direction of the Okinawa Trough changed from NW-SE to nearly N-S, which provided the stress source for the Okinawa Trough to enter the second spreading stage.Based on compositive analysis and interpretation of the observed and historical data, the geophysical field characters and structural properties of the Gagua “Wedge” Zone of the sea area east of Taiwan Island and the primary tectonic stress direction and its variabilities of backarc spreading in the southern Okinawa Trough are studied. It is concluded from the study results that the Gagua “Wedge” Zone is structurally consistent with the Gagua ridge and two fault basins on both sides of the Gagua ridge, and adjusts the moving direction and distance of the western Philippine Sea plate to make the northwestward motion of the plate on its east side change to the northward subduction of the plate on its west side so that the primary tectonic stress direction of the Okinawa Trough changed from NW-SE to nearly N-S, which provided the stress source for the Okinawa Trough to enter the second spreading stage.

关 键 词：EAST of TAIWAN Island  Gagua "Wedge" Zone  OKINAWA Trough  structural control. 

分 类 号：P544[天文地球—构造地质学]