Estimating the age of formation of lakes: An example from Lake Tanganyika
Estimating the age of formation of lakes: An example from Lake Tanganyika
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估计湖泊形成的年龄：以坦噶尼喀湖为例
DOI：
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发表时间：
1993
期刊：
影响因子：
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通讯作者：
C. Scholz
中科院分区：
文献类型：
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作者：
A. Cohen;M. Soreghan;C. Scholz
古湖泊的年龄估计对于确定其历史及其生物和构造演化速率非常重要。在缺乏来自湖泊沉积基底的过时的岩心材料的情况下，已经使用了几种技术来产生这样的年龄估计。其中最常见的方法在本文中称为反射地震-放射性碳法，它结合了从放射性碳定年岩心得出的短期沉积物堆积速率估计值和从同一地点或附近的反射地震数据得出的到基底的深度估计值，以估计到基底的年龄。年龄估计形式的RSRM表明，构造盆地的中央湖坦噶尼喀开始形成之间的9和12马。对北方和南方盆地的估计则较晚（分别为7至8 Ma和2至4 Ma）。对湖泊不同部分的历时性估计是不明确的，可能是由于北方和南方构造盆地的侵蚀损失或裂谷的逐渐打开。坦噶尼喀湖的RSRM年龄估计比大多数先前的估计要年轻得多，并澄清了东非裂谷系西部分支的伸展历史。参考文献31篇，图3，1个选项卡。
Age estimates for ancient lakes are important for determining their histories and their rates of biotic and tectonic evolution. In the absence of dated core material from the lake`s sedimentary basement, several techniques have been used to generate such age estimates. The most common of these, herein called the reflection seismic-radiocarbon method (RSRM), combines estimates of short-term sediment-accumulation rates derived from radiocarbon-dated cores and depth-to-basement estimates derived from reflection-seismic data at or near the same locality to estimate an age to basement. Age estimates form the RSRM suggest that the structural basins of central Lake Tanganyika began to form between 9 and 12 Ma. Estimates for the northern and southern basins are younger (7 to 8 Ma and 2 to 4 Ma, respectively). The diachroneity of estimates for different segments of the lake is equivocal, and may be due to erosional loss of record in the northern and southern structural basins or to progressive opening of the rift. The RSRM age estimates for Lake Tanganyika are considerably younger than most prior estimates and clarify the extensional history of the western branch of the East African Rift system. 31 refs., 3 figs., 1 tab.