Yarragadee Aquifer

Yarragadee Aquifer

The Yarragadee Aquifer is a significant freshwater aquifer located in the south west of Western Australia and predominately beneath the Swan Coastal Plain west of the Darling Scarp. It has a north-south range from about Geraldton to the south coast, but with a split in the formation south of Perth. The southern part is known as the South West Yarragadee Aquifer.

The aquifer is quite deep, situated hundreds of metres below ground level and with a thickness ranging up to about two kilometres.

In the Perth area, the Yarragadee Aquifer is located beneath the Leederville Aquifer, which itself is located beneath two superficial aquifers known as the Gnangara Mound and Jandakot Mound. These aquifers are separated by impervious layers with no groundwater called aquitards.

The Yarragadee Aquifer stores about 1000 cubic kilometres of water, compared to about 20 cubic kilometres in the Gnangara Mound. As such it is seen as a potential source of water, and the Water Corporation of Western Australia currently extracts about 45 gigalitres per year from the aquifer. One cubic kilometre is equivalent to 1000 GL.

Ultimately the Yaragadee Aquifer is replenished by rainfall. This recharging is usually where there are outcroppings near other aquifers like the Leederville Aquifer. There are also outcrops near the surface in the vicinity of the Blackwood River. Current models estimate this recharge at about 280 to 340 GL per year. This groundwater can remain in the aquifer for many years; in some areas the age of the groundwater is over 30,000 years.

Geologically, the aquifer is part of what is known as the Yarragadee Formation, which is a relatively thick geological unit in the Perth Basin. Formed during the Jurassic Period, the Yarragadee Formation is composed primarily of non-marine fluviatile feldspathic, poorly sorted sandstones which are porous and poorly cemented, hence allowing for considerable groundwater reserves. It grades from a shale-siltstone dominated base to a cleaner sandstone in the upper portions of the formation, probably representing increased subsidence or filling of the basin during the late Jurassic.

References

*
*
*
*
*
*


Wikimedia Foundation. 2010.

Игры ⚽ Поможем написать реферат

Look at other dictionaries:

  • Perth Basin — The Perth Basin is a thick sedimentary basin in Western Australia. It lies beneath the Swan Coastal Plain west of the Darling Scarp, representing the western limit of the much older Yilgarn Craton, and extends further west offshore. Cities and… …   Wikipedia

  • List of aquifers — The following is a partial list of aquifers around the world. A of aquifers is also available.North AmericaCanada * Oak Ridges Moraine North of Toronto Ontario * Laurentian River SystemUnited States* Biscayne Aquifer * Bruceian Aquifer * Edwards… …   Wikipedia

  • Perth, Western Australia — Perth, Australia redirects here. For the town in Tasmania, see Perth, Tasmania. For other uses, see Perth (disambiguation) and Perth, Western Australia (disambiguation). Perth Western Australia …   Wikipedia

  • Darling Scarp — Southwest Western Australia from space. The dark green is dense vegetation on and above the scarp, which has been retained for forest reserve and water catchment purposes. The sharp vegetation boundary on the coastal side coincides with the edge… …   Wikipedia

  • Darling Scarp — Südwestliches Western Australia aus dem Weltall betrachtet. Das dunkle Grün ist eine dichte Vegetation an und über der Scarp, die als Wälder und Wassereinzugsgebiet erhalten blieb. Die Grenze der Scarp Vegetation an der Küste stimmt mit der… …   Deutsch Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”