About South Australia’s Far North Mound Springs
Mound springs are natural outlets for the waters of the Great Artesian Basin (GAB), where artesian pressure forces water to the surface. Most springs occur on the margins of the Basin in the Far North of South Australia, north-western NSW and south-western Queensland.
Most of the springs have only small flows or seepages, but one at Dalhousie in the Far North of South Australia has a daily output of around fourteen million litres per day.
The term mound springs reflects the characteristic mounds that have developed at many (but not all) of the springs. In some areas the mounds have been building for thousands of years. Spring flows were stronger in the geological past.
The precipitation of salts and minerals, along with the erosion of the sands and clays of the surrounding country, has created the mounds.
Characteristic features of the landscape around many springs are the gibbers, deeply coloured and highly polished stones and boulders that are the broken up fragments of an old plateau. Wind and water have eroded the soil away, leaving the stones as a surface layer. Closely packed in many places, they are often referred to as desert pavement. The red and brown colouration, aptly called desert varnish, comes from a surface coating of iron and manganese oxides and the high polish is a result of thousands of years of sand blasting.