Indo-Australian Plate
The Indo-Australian Plate is a major tectonic plate that includes the continent of Australia and the surrounding ocean and extends north-west to include the Indian subcontinent and the adjacent waters. It was formed by the fusion of the Indian and the Australian plates approximately 43 million years ago. The fusion happened when the mid-ocean ridge in the Indian Ocean, which separated the two plates, ceased spreading. Contemporary models suggest at present there is a deformation zone between the Indian and Australian plates with both earthquake and global satellite navigation system data indicating that India and Australia are not moving on the same vectors northward. These observations are consistent with earlier evidence that the Indian Plate and Australian Plate have been acting as separate plates for at least the last 3 million years. In due course, some expect a localized boundary to reform between the Indian and Australian plates.