Estimation of erosion amount by geochemical characteristic in the Horonobe area, northern Hokkaido

Takahashi, Kazuharu; Niizato, Tadafumi  ; Yasue, Kenichi; Ishii, Eiichi   

This article presents the results of the estimated amount of erosion and uplifting based on mineralogy and organic geochemical characters of the Neogene siliceous rock (Wakkanai and Koetoi Formations) in Horonobe. As a result of the transformational change of silica minerals, it was clarified that the erosion amount was about 0.66 [m ky] or more at the large uplift site, and was about 0.21 [m ky] or more at the small uplift site at Hokushin region, Horonobe area. In this case of the correlation with the palaeo-geothermal temperature and the sterane/sterene ratio, the ratio is effective measure to estimate the burial depth and erosion amount. We think that the estimation of the amount of erosion and uplifting became possible in high a resolution by the organic geochemical character.