著者

米地 文夫

出版者

東北地理学会

雑誌

東北地理 (ISSN:03872777)

巻号頁・発行日

vol.14, no.1, pp.1-6, 1962

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In the southern part of the Shonai Plain, there are several surfaces of river terraces and terrace-like surfaces. These surfaces are classified and shown in Table and Figure 1.<BR>The Iwanoyama, Etchuyama Settlement and Otori Nursery-garden Surfaces, thus named respectively, are covered with &ldquo;Tsuruoka Loam&rdquo; (volcanic ash as eolian deposits), and their surfaces are wavy due to the dissection. A part of the Matsune Surface is covered with secondarily deposited loam. The Matsune and Nakano-shinden Surfaces preserve the flat terrace surfaces.<BR>The Etchuyama Sites are located on the Etchuyama Settlement Surface and Otori Nursery-garden Surface. Stone implements of the Non-ceramic Age are discovered from the level between black soil (humus) and the Tsuruoka Loam.<BR>After all, the writer supposes that the Tsuruoka Loam was derived from the upper Pleistocene Age, and that the time of the formation of the surfaces from the Iwanoyama to the Otori Nursery-garden Surface was the Pleistocene. The Matsune Surface is a landform of slightly elevated fan-like delta formed in the lower Holocene Age.