Ina Mountains - Inasanchi

A mountain range that runs north to south on the east side of the Tenryu River in southern Nagano Prefecture. The highest peak is Mt. Kimenzan at 1,890 meters above sea level, and the mountain range is generally a mid-mountainous range with mountain ridges of around 1,600 meters above sea level. It is a narrow mountain range that stretches about 100 kilometers north to south and 10 kilometers east to west from the southern part of Okaya City on the shores of Lake Suwa in the north to the Toyama River, a tributary of the Tenryu River near Shizuoka Prefecture in the south. On the east side of this mountain range, three rivers, Mibu, Koshibu, and Toyama, which are tributaries of the Tenryu River, run north to south, forming a straight valley, and the geological Median Tectonic Line of Southwest Japan runs through it, separating it from the Akaishi Mountains. For this reason, the Ina Mountains act as a front mountain for the Akaishi Mountains, and drop steeply into the tectonic valley on the east side, cutting off communication between the villages along this valley and the cities and towns along the Tenryu River. It slopes gently towards the Tenryu River on the west side.

[Hiroyoshi Kobayashi]

Source: Shogakukan Encyclopedia Nipponica About Encyclopedia Nipponica Information | Legend

長野県南部、天竜川の東側を南北に走る山地。最高峰は標高1890メートルの鬼面山(きめんざん)で、全体に1600メートル前後の山嶺(さんれい)が続く中山性山地。北は諏訪(すわ)湖岸の岡谷市南方から、南は天竜川の支流で静岡県に近い遠山(とおやま)川まで南北およそ100キロメートル、東西10キロメートルほどの狭長な山地である。この山地の東側は南北方向に天竜川の支流の三峰(みぶ)、小渋(こしぶ)、遠山の3川が流れて一直線の谷をなし、地質学上の西南日本中央構造線が走り、赤石山脈を隔てている。このため、伊那山地は赤石山脈の前山的存在をなし、東側の構造谷に向かって急斜面で落ち込み、この谷沿いの村々と、天竜川沿いの市町村との交通を分断している。西側の天竜川に向かっては緩傾斜をなす。

［小林寛義］

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