云南抚仙湖近现代环境变化的沉积物粒度记录
- 收稿日期:
1900-01-01
- 修回日期:
1900-01-01
- 刊出日期:
2010-08-10
摘要: 通过对云南抚仙湖沉积物柱芯样品的放射性核素210Pb和137Cs的测试，确定了过去129年的湖泊连续沉积序列。利用210PbCRS计年模式，计算出每个样品深度所对应的年代，与137Cs时标计年法比较存在一定的偏差，分析了两种计年方法存在差异性的原因。根据抚仙湖的湖区特点，对沉积物的粒度特征进行了分析。抚仙湖柱芯的粘土（<4 μm）、细粉砂（4～16 μm）和粗粉砂（16～63 μm）含量分别占约36%，44%和18%。粒度参数根据矩值法求得，平均粒径（值）为6.48～7.92，分选系数So为1.27～1.42，偏度SKD分布范围在-0.18～0.04之间。将整个柱芯的计年结果与粒度特征相结合，自1878年以来，抚仙湖的环境演化大致可以划分为4个阶段：自然演化阶段，人为扰动阶段，人为改造阶段，后期治理阶段。人类活动在特定的历史时期会对湖泊环境变化产生较大的影响。
Recent Environmental Change Inferred from GrainSize Records in Fuxian Lake, Yunnan Province
- College of Geography Science, Nanjing Normal University, Nanjing 210046
- Received Date:
1900-01-01
- Rev Recd Date:
1900-01-01
- Publish Date:
2010-08-10
Abstract: 210Pb and 137Cs were used to analyze for the Fuxian Lake sediment core. 210Pb (CRS) dating result showed a little deviation from 137Cs dating, and two reasons were investigated. According to the feature of Fuxian Lake, we analyzed the grain size characteristics and obtained the content of the core, which contained 36% of clay, 44% of fine sand and 18% of coarse sand. By calculation, the different grainsize parameters were also obtained, the mean grain diameter () was between 6.48 and 7.92, the standard deviation (So) was between 1.27 and 1.42, and the skewness (SKD) was between 0.18 and 0.04. Based on radionuclide dating and grainsize distribution characteristics in the sediment core, we concluded a sedimentary environment in Fuxian Lake had been greatly changed since 1878, which can be marked off four stages: natural evolution stage, manmade disturbances stage, manmade transformation stage, and recent treatment stage. Human activities of historical period had played a very important role in changing the environment of the Lake.
王小雷. 云南抚仙湖近现代环境变化的沉积物粒度记录[J]. 沉积学报, 2010, 28(4): 776-782.
| 引用本文: |
王小雷. 云南抚仙湖近现代环境变化的沉积物粒度记录[J]. 沉积学报, 2010, 28(4): 776-782.
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WANG Xiaolei. Recent Environmental Change Inferred from GrainSize Records in Fuxian Lake, Yunnan Province[J]. Acta Sedimentologica Sinica, 2010, 28(4): 776-782.
| Citation: |
WANG Xiaolei. Recent Environmental Change Inferred from GrainSize Records in Fuxian Lake, Yunnan Province[J]. Acta Sedimentologica Sinica, 2010, 28(4): 776-782.
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