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ID 26265
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title alternative
AMS-^<14>C Dates of Late Quaternary Tephra Layers Erupted from the Shikotsu and Kuttara Volcanoes
creator
Katoh, Shigehiro
Yamagata, Kotaro
subject
支笏火山
クッタラ火山
加速器質量分析(AMS)法
テフラ
噴出年代
NDC
Earth sciences. Geology
abstract
北海道南西部の支笏・クッタラ両火山から後期更新世に噴出した数多くのテフラの中で, Kt-1, Kt-TkおよびSsfa・Ssflの3つのテフラに関して, 3点の加速器質量分析(Accelerator Mass Spectrpmeter, AMS)法による14C年代値を得た. これらの年代値と, これまでに得られたAMS法による14C年代値を整理し, 両火山を起源とするテフラの噴出年代を, Kt-1が約4万年前, Kt-Tkが4.4~4.8万年前, Kt-3が4.7~5.1万年前, Ssfa・Ssflが4.7~5.3万年前であると推定した. また, Kt-1直上に層位するSpfa1の噴出年代は3.8~3.9万年前と, Kt-1とKt-Tkの中間に層位するZ-M(山縣ほか, 1989)の噴出年代は4.2~4.4万年前と, それぞれ推定された.
abstract
The Shikotsu and Kuttara volcanoes in southern Hokkaido often erupted violently during the Late Pleistocene and provided many time-marker tephra layers which are widely distributed to the east of them. These layers are important for the Quaternary tephrochronological studies in the Ishikari Lowland, Hidaka District, and Tokachi Plain. The nomenclature of the tephra layers here are based on Yamagata (1994).

We obtain there new radiocarbon dates by accelerated mass spectorometry (AMS-14C dates) : 39,290±970, 45,500±2,000, and 49,800±3,100 yrs BP for Kt-1, Kt-Tk, and Ssfa • Ssfl, respectively. By correlating these and other AMS-14C dates in previous studies, we estimate the eruption ages of tephra layers from the two volcanoes as follows : ca.40 ka for Kt-1, 44 - 48 ka for Kt-Tk, 47 - 51 ka for Kt-3, and 47 - 53 ka for Ssfa • Ssfl. In addition, the dates of Spfa 1 and Z-M are estimated 38 - 39 ka and 42 - 44 ka based on their stratigraphical relationships with the above tephra layers.
journal title
第四紀研究
volume
Volume 34
issue
Issue 4
start page
309
end page
313
date of issued
1995-10-31
publisher
日本第四紀学会
issn
0418-2642
ncid
language
jpn
nii type
Journal Article
HU type
Journal Articles
DCMI type
text
format
application/pdf
text version
publisher
department
Graduate School of Integrated Arts and Sciences