594 PERU. 
few feet. Indeed, the rapid transitions from one colour to another, 
and also from sandstone to shale, are a prominent characteristic of 
the rocks of the island. The sandstone layers are also various in tint, 
being of gray, whitish, and light reddish shades. In texture, they are 
mostly fine, though occasionally pebbly, and they often pass insen- 
sibly into the argillaceous shale. Lines of deposition are usually 
very distinct, occurring every ten or twelve inches, and generally at 
shorter intervals. ‘The sandstone is mostly rather fragile, and has a 
sandy surface; the shale falls into small chips on exposure, or upon 
being struck with a hammer. 
The following details of sections exposed, will give an idea of the 
frequent and abrupt transitions in the rock, and the riband colours 
which the cliffs exhibit. The first (fig. 1) was taken down on the 
north shores, and the whole height is about one hundred and eighty 
feet. The view represents also the faults which intersect the cliff. 
Beginning at the top :— 
24 feet.—Shale: purplish and bluish. 
1. 3 feet.—Shale; yellow. 
15 feet—Shale ; bluish, nearly black below. 
2. 40 feet.—Sandstone ; light grayish-red. 
3. 3 feet.—Shale ; light shades of blue and purplish. 
4. 6 feet.—Sandstone ; light grayish-red. 
5. 5 feet.—Shale ; light purplish. 
6. 25 feet.—Sandstone ; light grayish-red. 
7. 3 feet.—Shale; light bluish. 
8. 24 feet.—Sandstone ; light grayish-red. 
9. 2 feet.—Shale; light shade of colour. 
i 
oO 
. 2 feet——Sandstone ; light grayish-red. 
. 12 feet—Shale; mostly dark blue; upper four feet and lower foot very light 
coloured. 
. 13 feet.—Sandstone ; light grayish-red. 
. 1 foot.—Shale ; light bluish. 
. 7 feet.—Sandstone ; light grayish-red. 
. 83 feet.—Shale ; light bluish. 
Sandstone; grayish-red. 
= 
—_ 
ee el el 
an SP WwW Wh 
