火成岩の教材における指導上の問題点

Problems in Teaching of Igneous Rocks as Teaching Materials

恩藤 知典

廣島大學地學研究報告

Geological report of the Hiroshima University

Igneous rocks as teaching materials have many important advantages in instructing the student in geological outlook in nature. For this reason, these materials appear in every course of education in Japan, all through the elementary school, the lower secondary school and the upper secondary school, and they form what is called a spiral curriculum.
The teaching practices on those materials, however, still leave much to be desired from the educational standpoints as follows;
1. The teaching practices on these materials have not been carried out in intimate relation between successive stages in the curriculum, namely, between the elementary school and the lower secondary school, or the lower secondary school and the upper secondary school.
2. The practices in the observation of igneous rocks in the lower secondary school or in the upper secondary school lack in quantitative measurements on the natural materials.
3. The observation of rock-forming minerals has been done usually on individual specimens of minerals, not on the surface of igneous rocks.
4. The way to present the texture of igneous rocks and mineral assemblages has not been practiced on the specimens, but adheres only to the features on the thin sections of the rocks.
5. The statements of occurrence of igneous rocks in the textbooks are usually formal without noticing real occurrences.
6. In Japanese textbooks of these schools, tuff, tuff-breccia, and agglomerate are classified into the category of sedimentary rocks, not in igneous rocks. For this reason, many students of the elementary school have an erroneous idea that lava does not belong to the igneous rocks.
7. The nomenclature and technical terms used in Japan for igneous rocks have little connection with those in daily use, that causing a great deal of difficulties in studing them for the part of the students.
I have realized these problems mentioned above through observations in the laboratory as well as in the field, and I have tried to find out solutions to the problems in terms of education.

日本語

廣島大學理學部地學教室

[ISSN] 0073-2303

[NCID] AN00213676