Tokamachi Basin

A mountain basin located in the southern part of Niigata Prefecture, between the Sekita Mountains and the Uonuma Hills in the upper reaches of the Shinano River. It is a long, spindle-shaped depression that runs north to south, and the bottom of the basin has developed one of the largest high terrace groups in the country due to the intense ground movement at the end of the Quaternary Period. The center of the basin is Tokamachi City, known for its high-quality silk textiles, and the main roads and settlements are also located here. The high terraces are called "hara", and there are many large undeveloped areas such as Shomen-ga-hara, Kikyo-ga-hara, Nagumo-hara, Mujina-hara, and Date-hara, but development has been progressing recently as part of the Naeba Foothills Development Project.

[Hisao Yamazaki]

Source: Shogakukan Encyclopedia Nipponica About Encyclopedia Nipponica Information | Legend

新潟県南部の、信濃(しなの)川上流にある関田(せきた)山地と魚沼(うおぬま)丘陵に挟まれた山間盆地。南北に細長い紡錘状の断層角窪(くぼ)地で、第四紀末の激しい地盤運動を受けて盆地底は全国有数の高位段丘群が発達している。盆地の中心は高級絹織物産地として知られる十日町市で、主要道路や集落もここにある。高位段丘は原(はら)とよばれ、正面原(しょうめんがはら)、桔梗原(ききょうがはら)、南雲原(なぐもはら)、狢原(むじなはら)、伊達原(だてっぱら)などの大未開拓面が続いているが、最近は苗場(なえば)山麓(ろく)開発事業で開拓が進んでいる。

［山崎久雄］

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