Late Cenozoic paleoceanographic changes in the adjacent seas of the Ryukyu Islands.

1.从宫古群岛以东约2,200米深的海沟斜坡采集的活塞岩芯[KT84-14-Pl]：这个416 a长的岩芯记录了过去15万年来的许多古海洋学条件，从底栖有孔虫动物群、钙质微型浮游生物区系、浮游和底栖有孔虫测试的氧和碳稳定同位素、化学成分(特别是碳酸盐)和两个火山灰层的分析来看。这项综合研究的手稿已经准备好提交给《海洋微古生物学》杂志。1990.2年初发表了一部专著，描述了该岩芯的163个底栖有孔虫分类群(包括3个新属和10个新种)。活塞芯[RN87-PC4]采集自石垣岛以南2488米深的海沟斜坡：经证实，这一356厘米长的岩芯通过火山灰层和钙质超微浮游植物达到了约90,000年前的水平。底栖有孔虫对GLAC…的变化与KT84-14-P1相比，离子变化较小，可能是因为该岩芯的位置更偏南。活塞芯[RN89-PC3]采集自Kerama Gap东南海沟斜坡，水深2,486m：这个伸缩岩芯(长386厘米)似乎记录了过去约37万年的古海洋状况，基于三重证据；浮游有孔虫、钙质纳米浮游生物地层和火山灰层的氧同位素测量。浮游有孔虫三角洲随着冰川的变化而发生变化，尽管与KT84-14-P1相比没有观察到更微妙的波动。与KT84-14-P1.4的情况不同，底栖有孔虫也有类似的责任，主要成分分类群在岩芯中持续出现。岛津群广泛发育于冲绳群岛南部，被认为是7~1.7 Ma期间的海沟斜坡沉积。然而，根据对其底栖有孔虫的初步研究，认为该海沟的斜坡条件不同于今天或最新的第四纪。较少

1. Piston core [KT84-14-Pl] collected from the trench slope east off the Miyako Islands at the water depth of about 2,200 m: This 416 a long core has recorded many paleoceanographic conditions during the past 150,000 years, judging from analyses of benthic foraminiferal faunas, calcareous nannoplankton floras, oxygen and carbon stable isotopes of planktonic and benthic foraminiferal tests, chemical compositions (particularly carbonate) , and two ash layers. A manuscript of this synthetic study is prepared for submitting to the journal, Marine Micropaleontology. A monograph described 163 taxs (three new genera and 10 new species included) of benthic foraminifera from the core was published in early 1990.2. Piston core [RN87-PC4] collected from the trench slope south off the Ishigaki Islands at the water depth of 2,488 m: It is verified that this 356 cm long care attains to about 90,000 years ago by an ash layer and calcareous nannoplanktons. Benthic foraminiferal change against the glac … More iation change is less responsible than the case of KT84-14-P1, probably because of more southerly location of this core.3. Piston core [RN89-PC3] collected from the trench slope southeast off the Kerama Gap at the water depth of 2,486 m: This telescopic core (386 cm long) seems to have recorded the paleoceanographic situation for the past about 370,000 years based on three fold evidences; oxygen isotope measurements of planktonic foraminifera, calcareous nanno-plankton stratigraphy, and an ash layer. Planktonic foraminiferal delta^<18> has changed in response to glaciation change, although more delicate fluctuation is not observed in comparison with KT84-14-P1. Benthic foraminiferal fauna also similar responsibility and the major component taxa occur rather continuously through the core differing from the case of KT84-14-P1.4. The Shimajiri Group, which is broadly developed in the southern part of the Okinawa Islands, has been regarded as the trench slope sediments during the period from 7 Ma to 1.7 Ma. According to preliminary study of its benthic foraminifera, however, it is suggested that the trench slope condition differs from that of the present day or the latest Quaternary period. Less