Gyrolites from Irakawa, Yamagata Prefecture, and Otemo, Niigata Prefecture.

概要

論文の詳細を見る
Fine crystals of gyrolite were found in druses of Irakawa olivine dolerite, Yamagata Prefecture where the occurrence had been reported by Sakurai (1962). Coexisting minerals were analcite, thomsonite, natrolite and opaline silica. The result of chemical analysis indicates that Ca/Si is almost equal to 2/3. X-ray powder pattern of Irakawa gyrolite shows weak peaks of truscottite. New occurrence of gyrolite associated with analcite and calcite were also found from basaltic tuff breccia at Otemo, Niigata Prefecture. X-ray powder pattern shows that the sample contains no other sheet silicate such as truscottite. The c-periods of these gyrolites convert from 22.26À to 19.6À at about 400°C on the consequence of one layer dehydration for each unite layer.
日本鉱物科学会の論文