@article{oai:kitami-it.repo.nii.ac.jp:00006315, author = {笹木, 敏}, issue = {1}, journal = {北見工業大学研究報告}, month = {Dec}, note = {application/pdf, The volcanic ash which covers the wide areas of the Kitami district is said to be derived from the Kutcharo caldera. This paper(Part 1) contains the geological and mineralogical studies on the volcanic ash samples collected from forty typical locations. The outline is as follows :   1.The regions covered by volcanic ash in the Kitami district may be divided into,three zones based on stratification and mineral composition. A zone : the eastern area,B zone : the central area,C zone : the western area.   2.The volcanic ashes consist of five major minerals : volcanic glass,quartz,plagioclase,hypersthene and augite and two minor minerals : hornblende and mica group.   3.The clay minerals in volcanic ash are identified as allophane and halloysite in the studies performed by x-ray diffraction,electron micrograph and differential thermal analysis.}, pages = {115--127}, title = {北見地方の火山灰に関する研究(第1報) 火山灰の主として鉱物学的研究-}, volume = {4}, year = {1972} }