The Magnetostratigraphic Characteristics of some Shorter Cores from the Deep South China Sea Basin
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摘要: 对南海5个深海短柱样的磁性地层学特征进行研究后表明,在陆坡柱样沉积物中位于岩芯深约3m处的反向磁性段可与蒙戈磁偏移相对比。因此,对沉积速率相对较高的陆坡碳酸盐相而言,利用反向磁偏移地层事件,可以对代表地质时限较短的深海短柱样进行等时面分析。Abstract: During the一marine comprehensive investigation of the Central South China Basin(12一20。N )from the October 1983 to June 1984,38 sediment cores were obtained by the piston一sampler. The cores are generally not longer than 4m. The paleomagnetic measurement of 5 sediment cores selecting from the continental slope and deep plain has been carried out. The result shows:(1)all cores are mainly positive polarity and belong to Brunhes epoch;(2)the magnetostratigraphic differences exist between the slope cores and deep plain cores. The lower of slope cores reveals the existence of negative magnetic excursion. The chronology of the excursion has been stuffed by various methods, such as 14C,Th一230,δ18O and CaC03%,etc. We got two satisfying cycle curves of δ18O and CaC03% in the slope cores. In comparison with the magnetostratigraphy and Quaternary geochronology from the neighbour borehole of Tianyang Lake,it can be seen that the nagative polarity section of studied slope cores is in the lower stage 3 of δ18O and CaC03% curves .its stratum is approximately equal to that located Mungo magnetic excursion in the borehole from Tianyang Lake.
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Key words:
- Magnetostratigraphy /
- Deep sea cores /
- South China Sea
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[1] 李粹中,1987,东海海洋,6(1):10~19. [2] M. F. Barbetti. 1972, Nature, Vol. 239, p. 327一330. [3] M. F. Barbctzi. et al.,1979. Nature. Vo1.279, p.202一210 [4] P. Y. Cillot, et al. . 1979. Earth and plantary letters. Vol. A2, p. 499~450. [5] G. M. Hall,et al. 1978. Nature. Vol. 274.p. 462一464. -

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