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对冲绳海槽西部陆坡上两个航次 (95航次和 99航次 )共计 2 0 0 0多公里的单道地震资料进行分析和解译 ,对斜坡沉积环境下沉积体系发育、分布特征进行了研究。结果表明 :a)冲绳海槽西部斜坡环境下 ,上新世以来的沉积层均不同程度的变形和错动 ;b)存在两种斜坡相地震反射模式———退覆模式和叠覆模式 ,这两种模式都反映了冲绳海槽西部陆坡得到充足的沉积物供给 ;c)斜坡环境下主要发育陆架边缘三角洲、重力流沉积和水道充填等沉积体系 ;d)沉积层发育特征表明 ,冲绳海槽西部陆坡具有北段坡度缓、沉积物供应丰富、构造相对不活跃 ,中段坡度陡、沉积物供应充足、构造活动强烈 ,南段坡度陡、沉积供应相对较少、构造和火山活动十分强烈 3种主要沉积环境。西部陆坡的沉积特征也揭示了东海陆架向陆坡提供了大量碎屑沉积物质。
Based on the analysis and interpretation of more than 200 km single-channel seismic data from two voyages (95 voyages and 99 voyages) on the west slope of the Okinawa Trough, the development and distribution characteristics of sedimentary systems under the slope depositional environment were studied. The results show that: a) the sediments in the western slope of the Okinawa Trough have been deformed and dislocated to varying degrees since the Pliocene; b) there are two types of seismic reflection patterns of slope facies --- the degenerate pattern and the superimposed pattern, Both of these models reflect the adequate sediment supply on the western slope of the Okinawa Trough; c) sedimentary systems that mainly develop marginal deltas, gravity flow deposits and channel fillings in the slope environment; d) sedimentary layer development shows that the Okinawa sea The west slope of the trough has a gentle slope in the north, a rich sediment supply, relatively inactive tectonics, steep middle slope, abundant sediments, strong tectonic activity, steep slope in the southern section, relatively few sedimentary supplies and strong tectonic and volcanic activity. 3 The main sedimentary environment. The sedimentary characteristics of the western slope also reveal that the East China Sea shelf provides a large amount of debris deposits to the slope.