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冲绳海槽为半深海沉积环境。根据粒度、钙质生物壳体和浮岩玻屑的含量进行综合分类,共有24种沉积物类型。调查区西南部具有较多的陆源沉积物,东北部具有较多的玻屑和钙质生物壳体,因而构成了各综合类型。 海槽西北坡角闪石、绿帘石、锆石、磷灰石含量高,东南坡紫苏辉石含量高;调查区西南部Na_2O/K_2O<1,Fe_2O_3/FeO>1,可能与浊积物有关,东北坡正好与之相反,是偏酸性浮岩玻屑含量较高的体现。 沉积物的来源主要为陆源,次为火山喷发的浮岩玻屑和浮游有孔虫壳体。以海槽两侧而言,海槽西北坡沉积物中陆源物占优势,东南坡的岛源和海底火山物比较明显。
Okinawa Trough semi-deep sea sedimentary environment. According to the grain size, the contents of calcareous biological shell and pumice are comprehensively classified, a total of 24 sediment types. There are more terrigenous sediments in the southwestern part of the investigation area and more glassy and calcareous biological shells in the northeast, thus forming the comprehensive types. The contents of hornblendite, epidote, zircon and apatite in the northwestern trough of the trough are high, and the content of perihonite in the southeast slope is high. The Na 2 O / K 2 O 1 and Fe 2 O 3 / FeO> 1 in the southwestern part of the survey area may be related to the turbidity accumulation On the contrary, the northeast slope is just the opposite, which is the manifestation of the higher acid content of the floated rock with partial acidity. Sediments are mainly from terrestrial sources, volcanic eruptions of pumice and planktonic foraminifera shells. In terms of both sides of the trough, the sediments in the northwestern trough of the trough dominate, and the island source and submarine volcanism in the southeast slope are obvious.