| 摘要: |
| 对1992年5月取自冲绳海槽北段（水深113-1156 m，东经126°58.71′-129°9.06′，北纬28°41.75′-31°40.56′）92个表层沉积物中的底栖有孔虫数据进行R型因子分析。分析表明，黑潮流系有4个不同垂直水团的底栖有孔虫群落组合。其中Pseudorotalia indopacifica, Bolovina robusta, Cibicides margaritiferus, Textularia saggitula, Cibicides lobatulus和Quinqueloculina spp.代表黑潮流系的表层水; Hyalinea balthica，Caribeanella depressa, Cibicides praecinctus，Planulina wuellerstorfi和Melonis affinis代表黑潮流系的次表层水; Globobulimina pacifica, Globocassidulina subglobosa和Trifarina spp.代表黑潮流系的中层水; Oridorsalis tener, Martionottiella okinawaensis, Pullenia quinqueloba和Uvigerina dirupta代表黑潮流系的深层水。 |
| 关键词: 底栖有孔虫 群落组合 R型团子 冲绳海槽北段 |
| DOI： |
| 分类号: |
| 基金项目:国家自然科学基金资助项目，49105059号 |
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| RECENT BENTHIC FORAMINIFERAL DISTRIBUTIONS IN THE NORTHERN PART OF OKINAWA TROUGH |
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Li Tiegang, Cang Shuxi, Yan Jun
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Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071
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| Abstract: |
| Numerical analysis of benthic foraminiferal relative-abundance data from 92 surface samples taken from the northern part of the Okinawa Trough(113 -1156 m; 126°58.71′ - l29°9.06′ E, 28°41.75′ - 31°40.56′ N) in May of 1992 distinguishes separate thanatotopes and faunal assemblages related to the four water masses present within the depth range of the samples. Four significant factors identified by the R-mode factor analysis based on 36 species, account for 68% of the total variance.
Factor 1 accounts for 41% of the variance. Eighteen species belong to this assemblage. Pseudorotalia indopacifica, Bolivina robusta, Czbicides margaritzferus, Textularia saggitula and Cibicides lobatulus show the highest scores. A depth plot of the factor scores demonstrates that all significant scores are for samples taken from waters between 100-150m. Therefore, this assemblage is particularly associated with the Kuroshio Surface Water (KSW).
Factor 2 explains 12% of the variance. Eight species have significant positive loadings on this factor, and the strongest loading being shown by Hyalinea balthica, Carzbeanella depressa, Planulina wuellerstorfi and Melonis affinis. The factor scores show that the significant positive values are typical of the 150 - 500 m interval, approximately the depth range of the Kuroshio High-Salinity Water (KHSW).
Factor 3 accounts for 8.5% of the variance. Significant positive loadings are shown by 6 species. Among them Globobulimina paclfica, Globocassidulina subglobosa and Trifarina spp. are the most important components of this assemblage. The factor-score plot shows that all significant scores are for samples taken from waters between 300 - 800m, corresponding to the Subarctic Intermediate Water (SIW).
Factor 4 explains 6.5% of the variance. Four species of Oridorsalis tener, Martinottiella okinawaensis, Pullenia quinqueloba and Uvigerina dirupta have strong loadings on this factor. The plot of factor scores shows that this assemblage is best developed within the Okinawa Trough Deep Water (OTDW) in the 700 - 1050 m depth range. |
| Key words: Benthic foraminifera, Assemblage, R-mode factor, The northern part of Okinawa Trough |
