During the Palaeozoic, 545 to 251 Ma, the present landmass of Australia saw two stages of geological development. From 545 to 390 Ma shallow warm seas covered parts of central Australia, with a series of volcanic arcs and deep water sedimentation in the east. During this period between 480 to 460 Ma the Larapinta Seaway extended across the centre of Australia. Cycles of sedimentation and volcanism formed new continental crust, forming eastern Australia. There was a major orogeny in eastern Australia from 387 to 360 Ma. The continent was affected by glaciation around 330 Ma.