著者

安藤 寿男 勢司 理生 大島 光春 松丸 哲也

出版者

公益社団法人 東京地学協会

雑誌

地学雑誌 (ISSN:0022135X)

巻号頁・発行日

vol.104, no.2, pp.284-303, 1995-04-25 (Released:2009-11-12)

参考文献数

38

被引用文献数

14 23

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The Futaba Group is the Lower Coniacian to Lower Santonian, fluvial to shallow-marine sedimentary succession distributed in the southern Abukuma Belt in north Honshu. Fifteen depositional facies were discriminated. They include alluvial fan, meandering river, braided river, transgressive lag and upper shoreface to inner shelf sediments. It is divided into three formations, the Ashizawa (the Asamigawa and Obisagawa Members), Kasamatsu and Tamayama Formations in upward sequence. Each formation consists of a third-order depositional sequence (DS).The first depositional sequence (DS 1) has a lowstand systems tract (LST) as the lower main part of the Asamigawa Member distributed in the northern half of the area. It is lithologically characterized by upper alluvial fan conglomerate and mid to lower fan sandstone and siltstone nonconformably overlying lower Cretaceous granite (sequence boundary 1 : SB 1). In the southern periphery of the distributed area the member contains talus or upper fan angular conglomerate. The upper part of the member distributed over the area is interpreted to be transgressive conglomerate with a sharp base called a ravinement surface (RS 1) which was formed by transgressive shoreface erosion. It may represent transgressive systems tract (TST). The following highstand systems tract (HST) is represented by the upper shoreface to inner shelf, medium to fine sandstone of the Obisagawa Member.The Kasamatsu Formation (DS 2) unconformably (SB 2) overlying the preceding depositional sequence (DS 1), is substantially characterized by fluvial upward-fining successions composed of channel sandstone and flood plain siltstone. The third sequence (DS 3) is characterized by thick fluvial (braided river) sandstone of the lower to middle part of the Tamayama Formation interpreted as LST and the upper shoreface to inner shelf sandstone of the upper Tamayama interpreted as HST. The sudden lithofacies change between the Kasamatsu and Tamayama Formations implies some large-scale changes in fluvial depositional systems by sea-level fall (SB 3). The transgressive conglomerate just above RS 2 in the basal part of the upper Tamayama Formation represents a thin TST. The upper sequence boundary (SB 4) of DS 3 shows the conspicuous clinounconformity between the Futaba Group and the Paleogene Shiramizu Group.

著者

大島 光春 広谷 浩子 田口 公則 石浜 佐栄子

出版者

神奈川県立生命の星・地球博物館

雑誌

基盤研究(C)

巻号頁・発行日

2012-04-01

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科学館や子どものための博物館では、対象を子どもに絞り、体験・体感できるような展示を行っている。一方、自然史博物館では、恐竜・鉱物・昆虫などを静置し、大きい・美しい・珍しいなどの感動から、自然への興味関心を引き出している。このような展示は来館者にある程度の知識や経験を要求することが多い。しかし、子どもを対象にした場合、自然史への興味の導入には、科学館などのような動く展示が重要な役割を果たしていると考え、自然史博物館にふさわしい動的展示を開発し、それをさらに有効に活用できるプログラムを試行した。

著者

安藤 寿男 勢司 理生 大島 光春

出版者

日本地質学会

雑誌

日本地質学会学術大会講演要旨

巻号頁・発行日

vol.102, 1995-03-20