Studies of the Thermal State of the Earth The 20th Paper : Mountain Formation and Thermal Conduction.

Time-variations of temperature within a mountain range are calculated by applying the relaxation technique to solving an equation of thermal conduction in the following two-dimensional mountain models. 1) A mountain range which is formed by a rapid erosion. 2) Mountain formation is caused by water erosion, the speed of which is very slow and constant. 3) A volcanic intrusion penetrated a flat plain. The results of the computations indicate that an L-type isotherm pattern would not be actually observed in geothermal measurements provided the geologically accepted age of mountains is true. It is possible to roughly estimate the age of a volcanic dome if it is younger than a few 104 years. Mt. Minakamiyama, a volcanic dome in the central area of the Matsushiro Earthquake Swarm, seems to be older than 104 years, the conclusion being consistent with the result obtained by a K-Ar method.山岳が浸蝕や火山活動によつて形成された後,温度分布が時間の経過とともに,どのように変化して行くかを,熱伝導方程式によつて計算した.山岳形成モデルとして 1) 断層・地すべりの類によつて急に形成された場合. 2) ゆるやかな浸蝕で形成されて来た場合. 3) 火山活動によつて形成された場合.を採用した