Untitled research work

The Kamuikotan gorge area of the Kamuikotan metamorphic belt, west of Asahikawa, Hokkaido, is underlain by the Kamuikotan metamorphic rocks and serpentinite. This area is divided into two zones, the central and green rock zones, respectively. The metamorphic rocks of the central zone are basic and pelitic schists of the jadeite-glaucophane schist facies, retrograded in the lawsonite-albite facies, and those of the green rock zone are of the lawsonite-albite facies retrograded in the greenschist facies. No simple metamorphic zonation is possible in the Kamuikotan gorge area, because tectonic disturbance caused by the intrusion of serpentinite resulted in the mix-up of the rocks formed at different conditions, even though this area could roughly be divided into two zones. The mineralogy of alkali pyroxenes with the emphasis on the retrograde change of chemistry and texture are described in some detail.