region of the continental core of SE Asia. Sundaland is surrounded by the South China and India continental blocks to the north and Australia to the south. Fragments of Gondwana that reached as far north as Eurasia include Thailand and peninsular Malaysia. Other fragments that did not reach so far north form southwest Borneo's Schwaner Mountains in Kalimantan, and also Sumatra and Java.

The rifting, migrating northwards and accretion