花崗岩地帯を流下する河床砂の特質とその教材としての価値

The present authors have analyzed some characteristic features of river-bed sediments found in orogenic zones in Japan and considered their potentialities for teaching materials. They also try to investigate some features of sand in Hii River. The river runs through granitic rock areas and is the largest river in the eastern part of Shimane Prefecture. On the basis of the results, we suggest that it is necessary to take the three factors into account in developing teaching materials :(1) how the elements of river-bed sand change as we go down along the river to down the river, (2) whether there are any similarities or differences between river-bed sand and weathered products of granitic rocks. and (3) whether there are any similarities or differences between river-bed sand and coastal sand or dune sand.