台湾海峡西部海域底质柱状样中有孔虫特征及其环境意义

Feature of foraminifera in sedimentary cores from western Taiwan Strait and its environmental significance

本文通过对台湾海峡西部海域7个柱状样计79块样品中的有孔虫分析,阐述了海峡柱样中有孔虫组合及其特征,并由此讨论台湾海峡西部海域晚更新世以来的沉积环境。

About four hundred species of foraminifera have been found in 79 samples of seven cores from the western Taiwan Strait. The abundance of planktonic foraminifera is higher in northern than in the southern areas. There are Guembelitria vivans-Bolivina robusta assemblage in the upper part and two assemblages of Hanzawaia mantaensis-Ammonia compressiuscula and Bolivina robusta-Florilus decorus in the lower part of the northern area, and Hanzawaia mantaensis assemblage in the upper part and Ammonia assemblage in the lower part of the southern area. The results of foraminifera analysis indicate, shallow and nearshore environments in the middle and southern parts of the Taiwan Strait in Q_3~1; continental deposits of lower layer and inshore deposits of upper layer in the early Wurm-glaciation,and nearshore shallow water deposits and inshore deposits in the Wurm-interglaciation in Q_3~2; and shallow sea environment in the late Wurm-glaciation in Q_3~3. In the Holocene epoch ,the shallow sea environment was similar to that at present in the western part of the Taiwan Strait.