One of the present-day major lithospheric plates, which is having new material added to its south and south-west along the Carlsberg Ridge and the south-east Indian Rise, but its other margins are the collision zone of the Himalayan orogenic belt, subduction zones (e.g. in the E. Indies), or transform faults (e.g. the Alpine Fault in New Zealand). It is thought this plate may now be breaking into two separate plates along the line of the 90° E Ridge.