The Middle Pleistocene to Holocene tephrostratigraphy of the Takashima-oki core from Lake Biwa, central Japan
The Middle Pleistocene to Holocene tephrostratigraphy of the Takashima-oki core from Lake Biwa, central Japan
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发表时间：
2008-03
影响因子：
1.4
通讯作者：
Y. Satoguchi;Y. Nagahashi;A. Furusawa;Shusaku Yoshikawa;Y. Inouchi
中科院分区：
文献类型：
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作者：
Y. Satoguchi;Y. Nagahashi;A. Furusawa;Shusaku Yoshikawa;Y. Inouchi
近40万年来，在琵琶湖盆地沉积了一套厚层的沉积物，为近31年来的地层学和古环境研究提供了有用的资料。取于日本琵琶湖的高岛冲岩芯中含有大量的火山灰关键层，是近畿地区中更新世至全新世的地层岩芯类型之一。以前，在这个核心的火山灰进行了研究，其火山灰地层和年代的价值，但没有测量其重矿物的折射率，直到三虹膜研究。为此，我们使用了温度变化型折射计，并将火山玻璃的折射率与每个火山灰中的重矿物相关联。它们的相关系数不高，因此，各折射率值可作为自变量参数与其它地区火山灰进行相关。关键词：广布火山灰、折射率、重矿物、年代学、琵琶湖
Thick sequences of sediments have been deposited in the Lake Biwa basin for the last 400,000 years providing useful data for Quatern31'y stratigraphical and paleo-environmental studies. As the Takashima-oki core taken from Lake Biwa contains a large number of key tephra beds, it is one of the types of stratigraphical cores for the Middle Pleistocene to Holocene period in the Kinki district. Previously, the tephras in this core were studied for their tephro-stratigraphical and chronological values, but the refractive indices of their heavy minerals were not measured until tIris study. To do this we used a temperature v31'iation type refractometer and correlated the refractive index of volcanic glass sh31'ds with heavy minerals in each tephra. Their correlation coefficients are not so high, thus each refractive index is a useful value as an independent variable parameter for the correlation with tephra in other areas. Key-words: widespread tephra, refractive index, heavy minerals, chronology, Lake Biwa