Pialligo is a rural suburb of Canberra

Canberra

Canberra is the capital city of Australia. With a population of over 345,000, it is Australia's largest inland city and the eighth-largest city overall. The city is located at the northern end of the Australian Capital Territory , south-west of Sydney, and north-east of Melbourne...

, Australian Capital Territory

Australian Capital Territory

The Australian Capital Territory, often abbreviated ACT, is the capital territory of the Commonwealth of Australia and is the smallest self-governing internal territory...

, Australia

Australia

Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...

. The name Pialligo has been used for the area since at least 1820, and is probably of Aboriginal origin. It was also the name for the parish

Pialligo Parish, Murray

Pialligo Parish, Murray County is a parish of Murray County, New South Wales, a cadastral unit for use on land titles. It is now a very tiny piece of land to the north east of the Australian Capital Territory after most of the land in the parish was transferred to the ACT in 1911...

 in the area. Streets in Pialligo are named with Aboriginal words.

Beltana Road in Pialligo is home to many of Canberra's nurseries. Canberra International Airport

Canberra International Airport

Canberra International Airport , now trading as Canberra Airport, is the airport serving Australia's capital city, Canberra, and the city of Queanbeyan, NSW. Located at the eastern edge of North Canberra, it is the 8th busiest airport in Australia. The airport is the main hub for Brindabella Airlines...

 is located adjacent to Pialligo across Pialligo Avenue.

Geology

Quaternary alluvium

Alluvium

Alluvium is loose, unconsolidated soil or sediments, eroded, deposited, and reshaped by water in some form in a non-marine setting. Alluvium is typically made up of a variety of materials, including fine particles of silt and clay and larger particles of sand and gravel...

 covers the main western part of Pialligo. Calcareous shale

Shale

Shale is a fine-grained, clastic sedimentary rock composed of mud that is a mix of flakes of clay minerals and tiny fragments of other minerals, especially quartz and calcite. The ratio of clay to other minerals is variable. Shale is characterized by breaks along thin laminae or parallel layering...

s from the Canberra Formation are deep underneath.
The Woolshed Creek runs into the north end of Pialligo. This is a significant place, because in the bed of the
creek the Rev W B Clarke first recognised Silurian fossils. These fossils were brachiopod

Brachiopod

Brachiopods are a phylum of marine animals that have hard "valves" on the upper and lower surfaces, unlike the left and right arrangement in bivalve molluscs. Brachiopod valves are hinged at the rear end, while the front can be opened for feeding or closed for protection...

s, mostly Atrypa
duntroonensis. He discovered them around 1844 century and it was the first time that Silurian rocks were identified in Australia, and at the time were the oldest known rocks in Australia. This mudstone

Mudstone

Mudstone is a fine grained sedimentary rock whose original constituents were clays or muds. Grain size is up to 0.0625 mm with individual grains too small to be distinguished without a microscope. With increased pressure over time the platey clay minerals may become aligned, with the...

is from the Canberra Formation.