84 GEOLOGICAL RESEARCHES IN 



May 31st. Leaving Skiinope in the morning, we travelled northward, first through 

 a thickly wooded, swampy district, Avith corduroy road, then over a soil of volcanic 

 ashes, till we finally reached the sea-shore, when turning eastward, we skirted the 

 northern foot of the volcano, and crossing the outlet of the lake reached the fishing 

 village of Shkabe. 



The northern slope of the mountain was formerly covered with timber reaching 

 high up its side, and now represented by a forest of dead trunks extending over 

 thousands of acres. The trees were probably killed by the shower of pumice which 

 covered the surface to the depth of from six inches to two feet. On a large pro- 

 portion of the trees the bark is intact, and they show no signs of the action of fire. 

 A fresh undergrowth was springing up, at the time of our visit, and of this the 

 climbing plants seem to have been the first to start into life. 



In the side of a guUey in the blufi", I observed the following series from younger 

 to older: — 



1. Layer of pumice, two feet thick. 



2. Vegetable mould with roots of grass six inches. 



3. Layer of pumice, three to five feet. 



4. Thin layers of pumice and sand, apparently an ancient beach. 



5. Volcanic conglomerate-breccia. 



This section is repeated in all the cuttings observed at the foot of the volcano. 



At Shkabe there are several hot springs used for bathing. One of these, rising 

 on the beach and bubbling strongly, has a temperature of 75° C. ; and in another 

 rising in a cold stream, but protected by wooden tubbing, I found 70°. The water 

 of these springs has a slight odor of sulphuretted hydrogen. 



June 1st. Soon after leaving Shkabe we passed an outcrop of quartziferous por- 

 phyry, shoAving columnar structure, and remarkable for its richness in double pyra- 

 m id crystals of pellucid quartz associated with white felspar in a compact gray paste. 

 The volcanic conglomerate-breccia was the prevailing rock, but in places the bluff" 

 was formed of an apparently younger deposit of sandy clay. The beach was in 

 many places covered Avith a layer of magnetic iron sand, from the disintegrated 

 volcanic rocks, well concentrated by the action of the surf. 



From Shkabe eastward many fragments of vein quartz Avere seen on the beach. 



At the mouth of the Kakumi creek Ave left the sea-shore, and foUoAving the wild 

 valley rode a few miles inland to the mines of Kakumi. Here the hills are formed of 

 greenish and gray argillaceous rocks in places brecciated, in others metamorphosed 

 to an euritic rock. These are traversed by dykes of a peculiar Avhite porphyry. 



This porphyry has a compact paste, generally very Avhite, sometimes gray or 

 greenish, yielding fire with difficulty Avith the steel. In this are scattered grains, 

 and especially double pyramid crystals, of quartz, which form from a feAv per cent. 

 to one-third the volume. In rare instances it contains crystals of a white triclinic 

 felspar. Mica and hornblende are never present and rarely chlorite. It contains 

 almost ahvays small cubes of iron pyrites. 



In weathering it changes to a Avhite kaolin-like substance often discolored by the 

 oxidation of the pyrites. 



It occurs in dykes, and often shoAvs columnar structure. 



