徳島大学 教育・研究者情報データベース(EDB)

1. 西山 賢一([徳島大学.大学院社会産業理工学研究部.理工学域.自然科学系.地球科学分野]/[徳島大学.理工学部.理工学科.自然科学コース.地球科学講座])

   役割	任意
   貢献度	任意
   学籍番号	推奨

2. (日) 長岡 信治

   役割	任意
   貢献度	任意
   学籍番号	推奨

(英) Rock property changes of welded tuff due to weathering

(日) 溶結凝灰岩の風化による岩石物性の変化

(英) Temporal changes in colour and physical properties due to weathering during 240 ka were examined using welded tuff gravel in fluvial terrace deposits with a known emergence time that were distributed in Miyazaki Plain, Japan. The time between the age of each terrace formation (8, 90, 120 and 240 ka) and the present was assumed to be the weathering period.13;The results of the measurements are as follows: (1) effective porosity increases as the weathering period increases; (2) the a*, b*-values of colour induces increase as the weathering period increases. These results suggest that (1) the increase in pores in gravel that occurs as the weathering period increases is caused by the dissolution of biotite; (2) iron concentration and the formation of goethite occur in older gravels. Dissolution of biotite and increasing pore volume play major roles in the weathering of welded tuff.