The Collie Sub-basin is a pocket of

Permian The Permian ( ) is a geologic period and stratigraphic system which spans 47 million years from the end of the Carboniferous Period million years ago (Mya), to the beginning of the Triassic Period 251.9 Mya. It is the last period of the Paleoz ...

sedimentary rocks Sedimentary rocks are types of rock that are formed by the accumulation or deposition of mineral or organic particles at Earth's surface, followed by cementation. Sedimentation is the collective name for processes that cause these particles t ...

with an area of 225 km², enclosed within much older

Archean The Archean Eon ( , also spelled Archaean or Archæan) is the second of four geologic eons of Earth's history, representing the time from . The Archean was preceded by the Hadean Eon and followed by the Proterozoic. The Earth Earth ...

rocks of the

Yilgarn Craton The Yilgarn Craton is a large craton that constitutes the bulk of the Western Australian land mass. It is bounded by a mixture of sedimentary basins and Proterozoic fold and thrust belts. Zircon grains in the Jack Hills, Narryer Terrane have be ...

, near the town of

Collie Collies form a distinctive type of herding dogs, including many related landraces and standardized breeds. The type originated in Scotland and Northern England. Collies are medium-sized, fairly lightly-built dogs, with pointed snouts. Many ...

in southwestern

Western Australia Western Australia (commonly abbreviated as WA) is a state of Australia occupying the western percent of the land area of Australia excluding external territories. It is bounded by the Indian Ocean to the north and west, the Southern Ocean to th ...

.,Wilde S.A., Walker I.W. 1982. Collie, Western Australia, sheet SI50-6, 1:250 000 Geological Map Series, Explanatory Notes. Geological Survey of Western Australia.Wilson A.C. 1992. Collie Basin. In: Geology and Mineral Resources of Western Australia: Western Australia Geological Survey, Memoir 3, 525-531. Once considered a unique basin, this area, along with the smaller Wilga and Boyup Sub-basins to the south, are now classified as outliers of the

Perth Basin The Perth Basin is a thick, elongated 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. C ...

, separated from the main area by ancient earth movements and erosion. The Collie Sub-basin contains significant

coal reserves Coal is a combustible black or brownish-black sedimentary rock, formed as rock strata called coal seams. Coal is mostly carbon with variable amounts of other elements, chiefly hydrogen, sulfur, oxygen, and nitrogen. Coal is formed when de ...

, currently being mined mainly for

electricity generation Electricity generation is the process of generating electric power from sources of primary energy. For electric utility, utilities in the electric power industry, it is the stage prior to its Electricity delivery, delivery (Electric power transmi ...

.Le Blanc Smith G. 1993. Geology and Permian coal resources of the Collie Basin, Western Australia. Western Australia Geological Survey, Report 38.

References

Geology of Western Australia Sedimentary basins of Australia Landforms of Western Australia Collie, Western Australia {{Australia-geology-stub