GONG Jian-ming¹, CHEN Jian-wen^1,2, DAI Chun-shan¹, CAI Feng¹,
WU Zhi-qiang¹, YAN Gui-jing^1
1Qingdao Institute of Marine Geology, Qingdao 266071, China
² Ocean University of China, Qingdao 266071, China

　　East China Sea includes East China Sea Shelf Basin and Okinawa Trough Basin belonging to back-arc basin. Tectonically the latter is composed of three depressions and one uplift, that is, Lujiaqianyuan, Tokara and Haichao depressions as well Longwang uplift. The average water depth more than 1000 m is advantag eous to keep gas hydrate stable in Okinawa Trough. According to sedimentary thickness (the maximum Miocene thickness could reach to 5000-6000 m in Lujiaqianyuan depression) and sedimentary rate (maximum 400 m/ma), Lujiaqianyuan Depression lying west of Okinawa Trough is the most favorable to preservation and transformation of organic matter, so the depression could provide enough gas for gas hydrate to accumulation. Through integrated consideration of regional geological conditions (such as, water depth, geothermal gradient, sedimentary thickness and rate, organic carbon content etc) and geochemical anomalies (such as, methane anomalies of seabed sediments and seabed bottom water as well lower-layer atmosphere etc) and special procession and interpretation of seismic data (such as, dominant amplitude section, bright spot, Trace integration section, velocity spectrum section etc), we could draw a conclusion that south part of Okinawa Trough is probably more suitable to form and accumulate of gas hydrate, therefore, the south part probably has good perspective.