摘要
对1989－1991年期间，在台湾地区采集的5个湖泊的沉积物岩芯和22个湖泊水库的表层沉积物，进行了沉积物超量210Pb活性的分析，以探讨其沉积速率。其中，小鬼湖沉积物岩芯取部分样品进行14C定年，以与210Pb所得结果比较。结果表明，数千年来，台湾高山湖泊、次高山湖泊的沉积速率相当稳定，除万里池外，大多介于0．06－0．16cm／a之间。火山湖的210Pb活性较一般湖泊高，这是由于火山湖当地安山岩及地下水释出较多的210Pb所致，但这并不意味其沉积速率慢。所以应用210Pb对火山湖沉积物定年时，须作特别修正。平地湖泊目前沉积速率，除了大埔水库高达6．42cm／a外，大多介于0．5—3、2cm／a之间，比高山湖泊的沉积速率高约10－20倍。另外，由水库淤沙资料显示1），历年平均沉积速率都比目前的沉积速率快数倍，其中以石门、白河、乌山头、阿公店4个水库的平均沉积速率较快。
The 210Pb activities were measured in sediment cores from 5 lakes, and in surface sediments from 22 lakes and reservoirs in Taiwan during 1989- 1991, in order to calculthe the sedimentation rates. Samples from Xiaogni Lak were also datod by 14C.The results show that the sedimentation rates of alpine and subalpine lakes were fairiy constal during the past several thousand years, mostly ranging between 0.06 and 0.16cm / a- bos in the andesite area, such as Menghuan Lak and Lanyu-ten Pond,have higher 210Pb achvihes than those of non-volcanic ones. This is not because of the lower sedimentation nds, but is due to the extra 210 Pb input from andesite and ground-water nearby. The current sedimentation rates of low-land lakes are 10-20 folds higher than those of alpine and subalpine lakes, ranging between 0.5 and 3.2cm/ a,except for Dapu Reservoir (6.42cm / a).In addition, the theckness of sediment and the deposition rate in a reservoir can be eshmated from the siltation amount The average sedimentation rates of 11 reservoirs since their constructions are in the ranges of 0.18-22.75cm / a, and are several times higher than the present rates (0.44-6.42cm / a), with Shimen, Baihe, Wushantou and Akondain reservoirs being the highest.
出处
《海洋与湖沼》
CAS
CSCD
北大核心
1997年第6期623-631,共9页
Oceanologia Et Limnologia Sinica
基金
行政院国家科学委员会资助!NSC-82-0209-M-110-041
环保署及垦丁国家公园管理处资助
