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Perth Canyon is a submarine canyon located on the edge of the continental shelf off the coast of Perth, Western Australia, approximately 22 kilometres (14 mi) west of Rottnest Island. It was carved by the Swan River , likely before the Tertiary , when this part of the continental shelf was above sea level.
In and about Perth, the water owing to the force of the incoming seas at the mouth of the river presented a scene of a great lake, all the jetties were submerged, the high roads to Fremantle covered, and passage traffic rendered impossible quantities of sandalwood lying along the banks of river were washed away, and the inhabitants of the ...
Figure 1. A geologic cross section of the Grand Canyon. [5]The Tonto Group is a name for an assemblage of related sedimentary strata, collectively known by geologists as a Group, that comprises the basal sequence Paleozoic strata exposed in the sides of the Grand Canyon.
The Perth Basin is also prospective for natural gas and oil, with recent exploration wells, including Origin Energy/Arc Energy's Hovea 2, confirming large resources of natural gas, but difficult reservoir geology and characteristics have prevented the full utilisation of these energy reserves. The oil is sourced from the Kockatea Shale.
Abyssal plains are key geologic elements of oceanic basins (the other elements being an elevated mid-ocean ridge and flanking abyssal hills). In addition to these elements, active oceanic basins (those that are associated with a moving plate tectonic boundary) also typically include an oceanic trench and a subduction zone.
The geology of Australia includes virtually all known rock types, spanning a geological time period of over 3.8 billion years, including some of the oldest rocks on earth. Australia is a continent situated on the Indo-Australian Plate .
Geologic stratigraphic column of strata exposed in and near the Grand Canyon. The term Great Unconformity is frequently applied to the unconformity observed by John Wesley Powell in the Grand Canyon in 1869. [1] It is an exceptional example of relatively young sedimentary rock strata overlying much older sedimentary or crystalline strata.
Within the central Grand Canyon, Unkar strata occur in small, rotated, downfaulted blocks or slivers where they commonly are only partially exposed. Within this center part of the Grand Canyon, the Unkar Group is incomplete because pre-Tonto Group erosion has removed strata above the level of the middle part of the Dox Formation.