摘要: |
位于台湾省南部的大鬼湖,由于湖底常缺氧等特殊自然条件,使湖底沉积物免遭干扰,而能完整地记录过去气候的环境的变动.其岩芯中出现的白层,有明显较低的有机质含量和C/P、N/P、S/P及Si/Al比值.与较高的Si/P、Fe/C、Mn/C、Fe/Mn和Mg/Al比值,显示当时气候可能较干冷,集水区植生较差、湖水位较低,而且环境较氧化.相比之下,富含有机质的黑色沉积物,则反映气候较暖湿、湖水面至少升高2m,而且集水区土壤和水体较还原。 |
关键词: 古气候 湖积物 大鬼湖 元素比值 |
DOI:10.18307/1998.0303 |
分类号: |
基金项目:NSC87-2611-M-110-006-GP资助项目 |
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Pal eoenvironm ental Records From the Elem ental Distributions in the Sediments of Great Ghost Lake in Taiwan. China |
Lou Jiann-Yuh, Chen Chen-Tung Arthur
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Institute of Marine Geology and Chemistry, National Sun Yat-sen University, Gaoxiong 804, China
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Abstract: |
The sediments deposited in the anoxic Great Ghost Lake in southern Taiwan, China were undisturbed due to the lake's unique hydrological and geographic conditions. As a result, past cli-matic and environmental records were well preserved. The distinctive white laminations appeared in the generally black sediments are characteristic of lower organic-matter content. and lower C/ P,N/P,S/P and Si/Al ratios,but higher Si/P, Fe/C, Mn/C,Fe/Mn and Mg/Al ratios. These indicate times of cooler/driver climate,poorer plant growth around the drainage area, low-er water-level and more oxidized conditions in the soil and in the water column. On the other hand.the organic-matter-rich black sediments were deposited in a warmer/wetter climate under a more reduced condition. In addition, the variations in the Mg/Al rations seem to reflect at least 12% changes in salinity or water volume, or 2m changes in the water level. |
Key words: Paleoclimate 1ake sediment Grent Ghost Lake ratio of the elements |