@article{oai:nipr.repo.nii.ac.jp:00002015, author = {Suzuki, Morihisa}, journal = {Memoirs of National Institute of Polar Research. Special issue}, month = {Sep}, note = {P(論文), Ultramafic granulites in the East and West Ongul Islands area are grouped into two types, A and B. One of the fundamental criteria of the grouping is that type A does not yield plagioclase and type B does. Type A is characterized by the abundance of orthopyroxene and clinopyroxene and by the lack of plagioclase and garnet. It occasionally yields olivine. Type B is characterized by the presence of plagioclase and/or garnet and by the poverty in pyroxenes. In common cases, type A tends to occur as massive isolated blocks or pods in the surrounding gneisses, while type B as concordant sheets or layers showing a distinctly foliated structure. Between these two types, chemical characteristics of main constituent minerals such as orthopyroxene, clinopyroxene and hornblende are different from each other. Those in type A are comparatively more magnesian and less aluminous. Metamorphic temperature estimated from the pairs of orthopyroxene and clinopyroxene of both types is as high as around 800℃. Pressure condition is calculated based upon the associations of garnet, pyroxenes and plagioclase of type B to give the values around 7.5kb. The essential difference between the two types is inferred to reflect the difference in petrological characters of original rocks.}, pages = {85--100}, title = {Short note on ultramafic granulites in the Ongul Islands area, East Antarctica}, volume = {43}, year = {1986} }