[View larger image]

Geology

The central cone is a mass of scoriæ, and the section from here to the sea near the waterfall shows that there have been successive flows of basalt and trachyte. The high cliffs to the west of the landing are cut by a series of parallel dykes, which are an outstanding feature.

ISLANDS OF THE MID-ATLANTIC OCEAN

The St. Paul’s Rocks

These lie just north of the equator, almost midway between Africa and Brazil. These rocks are almost unique in occurrence, for, as Charles Darwin remarks in his journal, “Its mineralogical constitution is not simple.... It is a remarkable fact that all the many small islands, lying far from any continent, with the exception of the Seychelles and this little point of rock, are composed either of coral or erupted matter.”

The St. Paul’s Rocks are a group of eight or nine small rocky islands, the largest of which is only about 350 feet long by 150 feet wide. This island and the most northerly were the only ones where a landing was effected.

Sketch Map of St Paul’s Rocks