Mount Thullier, also known as Mount Thuillier, is a mountain on

Great Nicobar Island Great Nicobar is the southernmost and largest of the Nicobar Islands of India, north of Sumatra. It is part of India, in the Nicobar district within the union territory of the Andaman and Nicobar Islands. History The Nicobar Island has been ...

, located in the

Indian Ocean The Indian Ocean is the third-largest of the world's five oceanic divisions, covering or approximately 20% of the water area of Earth#Surface, Earth's surface. It is bounded by Asia to the north, Africa to the west and Australia (continent), ...

and bordering on the

Andaman Sea The Andaman Sea (historically also known as the Burma Sea) is a marginal sea of the northeastern Indian Ocean bounded by the coastlines of Myanmar and Thailand along the Gulf of Martaban and the west side of the Malay Peninsula, and separated f ...

. At above sea level, it is the highest point on the island and in the

Nicobar Islands The Nicobar Islands are an archipelago, archipelagic island chain in the eastern Indian Ocean. They are located in Southeast Asia, northwest of Aceh on Sumatra, and separated from Thailand to the east by the Andaman Sea. Located southeast of t ...

. The mountain is composed of parallel ridges of folded turbidite sandstone.P. C. Bandopadhyay and A. Carter. "Chapter 2: Introduction to the geography and geomorphology of the Andaman–Nicobar Islands". Geological Society, London, Memoirs, 47, 9-18, 2 February 2017, https://doi.org/10.1144/M47.2

/ref> The island's five perennial rivers – the Galathea, Jubilee, Amrit Kaur, Dak Aniang, and Dak Tayal – all originate from Mount Thullier. The Galathea River is the longest, flowing southwards for about 30 km to empty into the sea at Galathea Bay near the southern tip of the island. The hill is thought to have arisen due to tectonic activity in the region.

References

Great Nicobar Island Mountains of the Andaman and Nicobar Islands {{AndamanNicobar-geo-stub