The island groups of India can be divided into 2 parts according to their location. They are:The islands of the Bay of Bengal andThe islands of the Arabian Sea.1. The islands of the Bay of BengalAmong the islands located in the Bay of Bengal the most important group is the Andaman and Nicobar group of islands. These islands are mainly the upper parts of mountains rising from the floor of the Bay. This is the reason why at different parts of the islands small hills can be seen distributed irregularly. They range in height between 400 to 500 meters e.g. Mount Harriet in the South Andamans. The highest peak of the Andaman group of islands in Saddle Peak (750 meters). The barren and Narcondam islands have volcanoes. Some islands are surrounded by coral reef. In the month of June 1991, the dormant volcano in the Barren islands suddenly erupted. It erupted again in January 1991, the dormant volcano in the Barren island suddenly erupted. It erupted again in January 1995. The volcano in the Narcondam island is still quiet so it s an extinct or dead volcano.2. Islands of the Arabian SeaOff the Malabar coast of Kerala lay the islands of Amindivi, Lakshadweep and Minicoy. They lie in the Arabian Sea. These islands have been formed by deposits of millions of corals and so form coral islands. Thus the soil of these islands is also very fertile.