| 摘要: |
| 长江三角洲地区是我国重要工农经济区，对其第四纪地质的研究对于了解该区水文工程地质、河口海岸演变和土地开发利用有着十分重要的意义。为了进一步对该区第四纪地层的划分对比提供年代地层学上的依据，我们先后对和桥、梅捻、正仪、祝塘、吴江、北坎、常州、江都八个地方钻孔的沉积岩芯进行了古地磁的研究，并对部分样品进行了放射性碳年代测定，初步建立了本区的古地磁极性变化年表。 |
| 关键词: 长江三角洲 沉积岩芯 古地磁 |
| DOI： |
| 分类号: |
| 基金项目:中国科学院海洋研究所调查研究报告第1062号 |
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| PALEOMAGNETIC STUDY OF SOME SEDIMENT CORES FROM THE CHANGJIANG DELTA |
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Zhang Minghan, Gao Mingde
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Institute of Oceanology, Academia Sinica
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| Abstract: |
| This paper presents the results of a paleomagnetic study of eight sediment cores from the Changjiang Delta. A total of 851 samples were measured. The results of paleomagnetic measurements are combined with the results of the measurements of the C14age, which may be correlated with the geomagnetic polarity reversal scales of Cox (1969) back to about 4.5 million years ago. We have established the geomagnetic polarity reversal scales of the sediment cores in this region, ascertained the depth range of the polarity epoch and events, calculated sedimentation velocity among them and differentiated the Quaternary strata.
The depths from the Brunhes normal polarity epoch to the Matuyama reversal polarity epoch are between 65-248 m, from the Matuyama reversal polarity epoch to the Gauss normal polarity epoch are between84-321 m. We have taken the Mammoth event in Gauss normal polarity epoch ,for the bottom of the Quaternary.The iresu1ts of the calculation of the sedimentation velocities show that their velocities increased gradually from the Early Pleistonece to the Holocene. |
| Key words: PALEOMAGNETIC SEDIMENT CORES CHANGJIANG DELTA |
