Explanation of Plate HI. (PliotomicrogTaplis) 



Fig. 1. Siclentized slate forming the AAalls of the Daiseu vein. Ordinary 



light. Magnified 60 diameters. S, bleached shite ; L, veinlets of Kmouite 



altered from siderite ; SL, siderite veinlets altered to limonite along the 



selvages. 

 Fig. 2. Diopsidized slate (or diopside-horufels), collected on the road-side 



between Akénobé and Fndono Pass. This is a portion of the rock, which 



is composjed almost wholly of minute crystals and gi'aius of diopside (D). 



Ordinary hght. Magnified 60 diameters. 

 Fig. ?). Garnetiferous felsite-porphyry, forming a dike, found in the Yebisu 



adit. Oi'dinaiy light. Magnified 60 diametei-s. G, garnet ; F, altered 



feldspar phenocryst. 

 Fig. 4. P}Toxene andésite, a dike cutting the Daisen vein. It is usually 



•N'en' altered. Ordinary light. Magnified 60. diameters. F, plagioclase ; 



C, secondarj' calcite. No pyroxene is shown in this photomicrograph. 

 Fig. 5. Diabase, a dike cutting the Daiseu vein. White and hght-colom'ed 



parts are feldsi)ar crystals (F) and altered felds^xir ; the dark-colom'ed 



parts are minute flakes of chlorite, m = Magnetite ciystals. Oi'dinary 



liy-ljt. Maenified 50 diameters. 



