南海晚更新世至全新世的沟鞭藻类

LATE PLEISTOCENE—HOLOCENE DINOFLAGELLATE CYSTS FROM SOUTH CHINA SEA

南海深海盆地晚更新世至全新世的沟鞭藻以热带-亚热带大洋种类为主,伴有浅海种和河口湾种及温带-寒带种。本文对其中的9个属18个种包括5个未定种的沟鞭藻进行了描述,并据柱状剖面沟鞭藻种类的百分率的变化把KS01井的上部划分出两个暖气候期和一个偏凉的气候期;其下部出现的早更新世至中新世的沟鞭藻囊孢反映了不稳定的沉积环境。

In order to understand the mechanism responsible for the Quaternary climatic changes in SouthChina Sea,dinoflagellate cysts have been studied for piston core,KS01,located at 14°57′, 7′N, 116°05,5′E,at a water depth of 4 170m. Abundant dinoflagellate cysts were contained in the samples, principally of tropical--subtropicalspecies,accompanied by tropical neritic and estuarine species and temperate--arctic species. The characteristics of dinoflagellate assemblages indicate that the core can be divided into climaticstages. In the upper port of the core(1. 70m to the surface)dinoflagellate cysts are well--preserved. Twotemperate stages corresponding to the Holocene and the last interglaciation are represented,seperated bya cold stage corresponding to the last glaciation. In the lower part of the core, the sedimentation is disturbed by reworking due to turbiditycurrents. Dinoflagellate cysts of Miocene to early Pleistocene are present in the Quaternary sediments. The present paper describes 18 dinoflagellate cyst species together with their geographic andstratigraphic distribution.