Most of this region is resting on the Indian Plate, the northerly portion of the Indo-Australian Plate, separated from the rest of the Eurasian Plate. The Indian Plate includes most of South Asia, forming a land mass which extends from the Himalayas into a portion of the basin under the Indian Ocean, including parts of South China and Eastern Indonesia, as well as Kunlun and Karakoram ranges, and extending up to but not including Ladakh, Kohistan, the Hindu Kush range and Balochistan. It may be noted that geophysically the Yarlung Tsangpo River in Tibet is situated at the outside of the border of the regional structure, while the Pamir Mountains in Tajikistan are situated inside that border.