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サロベツ原野における沖積層の地質解析
Title: | サロベツ原野における沖積層の地質解析 |
Other Titles: | Geological Analysis of Alluvium in the Sarobetsu Moor |
Authors: | 酒井, 利彰1 Browse this author | 井岡, 聖一郎2 Browse this author | 石島, 洋二3 Browse this author | 五十嵐, 敏文4 Browse this author →KAKEN DB |
Authors(alt): | Sakai, Toshiaki1 | Ioka, Seiichiro2 | Ishijima, Yoji3 | Igarashi, Toshifumi4 |
Keywords: | Sarobetsu moor | alluvium | sedimentary environment | crustal movement | サロベツ原野 | 沖積層 | 堆積環境 | 地殻変動 |
Issue Date: | 10-Apr-2011 |
Publisher: | 日本応用地質学会 |
Journal Title: | 応用地質 |
Volume: | 52 |
Issue: | 1 |
Start Page: | 2 |
End Page: | 13 |
Abstract: | 北海道北部サロベツ原野における沖積層の地質構造と堆積環境を明らかにすることを目的に, 5本のボーリングコアを用いC/S分析,14C年代分析を行った. その結果,沖積層を4部層に区分でき,連続性の高い砂礫層や粘土層などの分布形態を推定できた. これに基づき次のとおり堆積環境を推定した. 10.5-14.5kyr BPは網状河川と湖沼が主体であり,末期には海退があった. 8 -10.5kyr BPは氾濫原が主体であった. 6.2-8kyr BPはパリアーラグーンおよび干潟が主体であった. 6.2kyr BP以降は氾濫原が主体であった. 海成堆積物の変位から次のとおり地殻変動を推定した. 6.2kyr BP以降にサロベツ原野域が丘陵部に対し相対沈降した. 変位速度は最大で1.5mm/yrとなり得る. 6-10kyr BPにはサロベツ原野中央~沿岸部が原野東部に対し相対沈降した可能性がある. | 5 boring cores were studied by using C/S analysis and 14C dating techniques, with the aim of elucidating the geological structure and sedimentary environment of Sarobetsu moor in the northern part of Hokkaido. Alluvium was divided into 4 groups, and the distribution of sand and gravel or clay strata with high continuity was estimated. On the basis of these results, the sedimentary environment of Sarobetsu moor was estimated as follows. Braided rivers and lakes were predominant during 10.5∼14.5 kyr BP, and there was a regression at 10.5 kyr BP. Floodplains were predominant during 8∼10.5 kyr BP. Barrier lagoons and tidal flats were predominant during 6.2∼8 kyr BP. Floodplains were predominant after 6.2 kyr BP. Tectonic movement was detected from the displacement of marine sediments. The main area of Sarobetsu moor subsided relative to the hilly area after 6.2 kyr BP. The rate of subsidence might be 1.5 mm/yr at the maximum. The region between the coastal area and the central part of Sarobetsu moor might subside relative to the eastern area during 6∼10 kyr BP. |
Type: | article |
URI: | http://hdl.handle.net/2115/52215 |
Appears in Collections: | 工学院・工学研究院 (Graduate School of Engineering / Faculty of Engineering) > 雑誌発表論文等 (Peer-reviewed Journal Articles, etc)
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Submitter: 五十嵐 敏文
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