Iron-rich pumpellyite and prehnite from the Miocene gabbroic sills of the Shimane Peninsula, Southwest Japan

Abstract

In the three Miocene gabbroic sills of the Shimane Peninsula , pumpellyite and prehnite are found to occur as secondary minerals replacing the primary minerals and as druse minerals . Additionally, prehnite, together with minor amounts of other minerals , not infrequently forms veins and nodular aggregates. The electron probe microanalysis shows that the range of the Fe/Al ratio in both minerals are fairly wide, and their maximum iron contents represent the highest in pumpellyite and prehnite ever reported from Japan.