Stratigraphy of Pleistocene Deposits Forming Marine Terraces in the Tanabu Plain, Shimokita Peninsula, Northern End of Honshu, Japan, in Relation to Relative Sea-level Changes

概要

論文の詳細を見る
Under the relative sea-level change during the Pleistocene epoch, marine-terrace deposits were thickly accumulated in the Tanabu Plain, which belongs to the tectonic depression running along the volcanic front in the Northeast Japan arc. The marine succession of the middle and late Pleistocene epoch in this plain includes at least four depositional sequences, named the Gamanosawa, Toei, Kabayama, and Tonamigaoka Formations from lower (older) to upper (younger). The sequences form the marine terraces named the Gamanosawa, Toei, Kabayama, and Tonamigaoka surfaces, respectively, from higher (older) to lower (younger). Each of the sequences has two depositional units. Each lower unit in the sequences is a thick mud, sand, and gravel layer which fills valleys with the sedimentary facies, indicating an estuary paleoenvironment. Each upper unit in the sequences is a sand and gravel layer which thinly overlies a wave-cut platform with the sedimentary facies, indicating a strand plain paleoenvironment. The depositional environment of each of these sequences shows that relative sea-level changed from transgression to regression at that time. The transgression deduced from the youngest sequence, namely the Tonamigaoka formation, tephrochronologically represents the high stand of the marine isotope stage 5e. Therefore the transgressions deduced from the three older sequences-Gamanosawa, Toei, and Kabayama-represent high stands earlier than the marine isotope stage 5e, probably the high stands of the middle Pleistocene epoch.
日本第四紀学会の論文

Stratigraphy of Pleistocene Deposits Forming Marine Terraces in the Tanabu Plain, Shimokita Peninsula, Northern End of Honshu, Japan, in Relation to Relative Sea-level Changes

スポンサーリンク

概要

著者

関連論文

スポンサーリンク