Igneous rocks play a major part in the landscape here, with volcanic plugs, necks and lava flows having helped shape the topography we now see. The chapter entitled 'Volcanoes of the steamy wetlands' explains more in 'Death of an Ocean' by E Clarkson and B Upton, Dunedin Edinburgh, 2010.
Uploaded to Geograph by Jim Barton on 30 June 2014
Photo © Jim Barton, 30 June 2014. Licensed for reuse under this Creative Commons licence