ABSTRACT
The Comores Archipelago is a chain of four volcanic islands between the east coast of Africa and Madagascar stretching across the Mozambique Channel (Figure 1). Those four islands were all formed rather recently, in geological terms, by volcanic action. The oldest one, Mayotte (Maore), is in the east and is thought to be about eight million years 01d;1 the youngest one at the extreme western part, Ngazidja, still has an active volcano almost 3,000 m. high, the Karthala. The two other islands, Mwali and Ndzuani, are located between Ngazidja (Grande Comore) and Maore, and are equally of the same geological origin.
