The plains and steppes already described lie either within or close to the tropics.
The sea extended up the Murray basin into the western plains of New South Wales.
Oxley now turned aside - led by Mr Evans's report of the country eastward - crossed the Arbuthnot range, and traversing the Liverpool Plains, and ascending the Peel and Cockburn rivers to the Blue Mountains, gained sight of the open sea, which he reached at Port Macquarie.
North of Bathurst, in the Macquarie plains, gold was discovered, in February 1851, by Mr E.
As the low-lying plains are altogether an alluvial deposit, the coarser sediments accumulate in the regions where the river first overflows its banks to spread out over the plains.