It is exceptional as an unglaciated granite massif of special geological interest and unusual, striking topography.
Granite, gabbro and leucogabbro with associated anorthosite make up the massif together with minor monzonite.
Several spurs of hills run west- east from the main upland massif, increasing local topographical complexity by more or less dividing the lowlands into a series of semi-enclosed coastal basins.
These include the wonderful map of the massif that he produced in 1960, and of which part is reproduced in the book.
Zones (windward and leeward) were designated in respect to the central massif whose orographic influences result in a marked precipitation gradient.
Folded to various degrees in the piedmont zone, they give way sometimes to alternating granite, metamorphic or volcanic massifs.
We analysed variation in fire frequency by climate, elevation and aspect (windward and leeward of the central massif).
In addition, late brittle faults are clearly visible in the mountain walls in both gneiss and quartz syenite massifs.
