ID | 117523 |
タイトル別表記 | Extracting-method of pyrite micrograins as an indicator for mudstone weathering
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著者 |
佐藤, 威臣
国土防災技術
竹熊, 隆宏
国土防災技術
長谷川, 修一
香川大学
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キーワード | mudstone weathering
slaking
framboidal pyrite
oxidation
hydroxidation
extracting methodology
HF-processing
biomineralization
oxygen minimum zone
anoxic event
Cretaceous
Fujikawa Shale
Monobegawa Group
non-accreted formation
Kurosegawa Terrane
environmental geology
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資料タイプ |
紀要論文
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抄録 | Applying to the indicator of mudstone weathering, an extracting method of pyrite micrograins and the secondary materials formed by oxidation and hydroxidation was examined using water diluted HF (3%). Based on the condition of extracted materials, the weathering grade of the drilling-cores of the Lower Cretaceous Fujikawa Shale Formation was subdivided into Oxidized- (weathered), Fresh-Oxidized Coexistence-, and Fresh- (non-weathered) zones in the order from the ground surface. The Fresh Zone is identified by only occurrence of non-altered primary pyrite micrograins that originate a bio-chemical process in sedimentary stage, and are characterized by aggregation of framboidal (raspberry-like), tubal (pellet-like), cubic and dodecahedral shapes. In the Fresh-Oxidized Coexistence Zone, pyrite micrograins and the secondary materials (hematite, goethite and limonitic hydrous ferric oxides) formed by oxidation and hydroxidation of pyrite co-exist, whereas the Oxidized Zone is characterized by the occurrence of ferric secondary materials without primary pyrites. A pyrite-alternation model was proposed in relation with the progressing of slaking. The Extracting-method of pyrite micrograins is useful even the case that the pyrite peak is not detected by X-ray analysis because of lower containing percentage.
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掲載誌名 |
自然科学研究
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ISSN | 09146385
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cat書誌ID | AN10065859
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出版者 | 徳島大学総合科学部
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巻 | 20
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開始ページ | 25
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終了ページ | 33
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並び順 | 25
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発行日 | 2006-12-22
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EDB ID | |
フルテキストファイル | |
言語 |
jpn
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著者版フラグ |
出版社版
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部局 |
理工学系
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