Varved Lacustrine Sediments in Japan:Recent Progress
Varved Lacustrine Sediments in Japan:Recent Progress
复制标题
日本变化湖沉积物:最新进展
DOI：
--
复制
发表时间：
1999
期刊：
影响因子：
--
通讯作者：
H. Fukusawa
中科院分区：
文献类型：
--
作者：
H. Fukusawa
每年层状（变化的）湖泊沉积物提供了末次冰期和全新世古环境的潜在连续、高分辨率记录。 1991-1993年，从日本西南部的两个湖泊水月湖和东乡池成功采集了长序列的层状湖泊沉积物。根据纹层计数和AMS 14C测年，我们澄清这些层状沉积物是varves。这些变化沉积物中的粘土矿物成分可以通过从中国黄土高原输送来的风尘浓度以及两个湖泊周围的降水来反映。此外，海藻中硫化铁和碳酸盐的形成可能是由海平面变化引起的海水入侵的周期性变化引起的。自末次冰河期以来，在两个湖泊沉积物的变化序列中检测到灰尘和铁矿物浓度的每年到十年的振荡。对这些沉积物的详细沉积学分析揭示了水藻的年代学、水藻的形成过程以及海平面和气候的年度到十年的变化。一些气候变化可能与格陵兰冰芯和海洋沉积物中观察到的突变（新仙女木事件和海因里希事件）有关。
Annually laminated (varved) lacustrine sediments provide a potentially continuous, high-resolution records of the last glacial and Holocene paleoenvironments. In 1991-1993, long sequences of laminated lacustrine sediments were successfully taken from two lakes in southwestern Japan, Lake Suigetsu and Lake Tougouike. Based on lamina counting and AMS 14C dating, we clarified that these laminated sediments were varves. Clay mineral composition in these varved sediments would be reflected by eolian dust concentrations, transported from Chinese Loess Plateau, and by precipitations around both lakes. Also, formation of iron sulfides and carbonates in varves would be caused by cyclic changes of sea-water invasion, originated from sea-level changes. Annual to decadal oscillations of dust and iron mineral concentrations since the last glacial were detected in varved sequences of both lake sediments. These detailed sedimentological analysis of these sediments revealed varve chronology, process of varve formation and annual to decadal changes of sea-level and climate. Some of the climatic changes may correlate with abrupt changes (Younger Dryas and Heinrich events) observed in Greenland ice cores and marine sediments.
DOI：
10.4116/jaqua.34.135
发表时间：
1995-08
期刊：
The Quaternary Research (daiyonki-kenkyu)
影响因子：
--
作者：
H. Fukusawa
通讯作者：
H. Fukusawa