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Stone Wall (Australia)
Stone Wall is an escarpment overlooking the Murchison River Gorge about north-east of Kalbarri in Mid West Western Australia. It is of geological interest because it provides outstanding exposures of five Cretaceous formations unconformably overlying the Ordovician Tumblagooda sandstone. The Cretaceous formations contain trace fossils of ''Skolithos ''Skolithos'' (formerly spelled ''Scolithus'' or ''Skolithus'') is a common trace fossil ichnogenus that is, or was originally, an approximately vertical cylindrical burrow. It is produced by a variety of organisms in shallow marine environment ...'' and '' Cylindricum''. It has been visited on geological excursions and is considered an important research site. References * * Escarpments Geology of Western Australia Heritage places of Western Australia Western Australian places listed on the defunct Register of the National Estate Mid West (Western Australia) {{WesternAustralia-geo-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Escarpment
An escarpment is a steep slope or long cliff that forms as a result of faulting or erosion and separates two relatively level areas having different elevations. The terms ''scarp'' and ''scarp face'' are often used interchangeably with ''escarpment''. Some sources differentiate the two terms, with ''escarpment'' referring to the margin between two landforms, and ''scarp'' referring to a cliff or a steep slope. In this usage an escarpment is a ridge which has a gentle slope on one side and a steep scarp on the other side. More loosely, the term ''scarp'' also describes a zone between a coastal lowland and a continental plateau which shows a marked, abrupt change in elevation caused by coastal erosion at the base of the plateau. Formation and description Scarps are generally formed by one of two processes: either by differential erosion of sedimentary rocks, or by movement of the Earth's crust at a geologic fault. The first process is the more common type: the escarpment is a t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Murchison River Gorge
Murchison River Gorge is a riverine gorge in Mid West Western Australia. Carved by the meandering lower reaches of the Murchison River, it is more than long, and up to deep. It begins about north-northwest of Ajana, and extends to the mouth of the river at Kalbarri. A site of outstanding natural beauty, it is a major tourist attraction, with points of interest including the Z Bend lookout and The Loop walking trail. The gorge is also of interest to geologists, with exposures of Tumblagooda sandstone, an Ordovician redbed formation that contains fossils of eurypterids, representing some of the earlier fossil evidence of land animals. Fossilised eurypterid tracks are common in the vicinity of the gorge, as are tracks of other arthropods, possibly trilobites. The gorge is considered to be in excellent condition and lies almost entirely within the Kalbarri National Park Kalbarri National Park is located north of Perth, in the Mid West region of Western Australia. The ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mid West (Western Australia)
The Mid West region is one of the nine regions of Western Australia. It is a sparsely populated region extending from the west coast of Western Australia, about north and south of its administrative centre of Geraldton, Western Australia, Geraldton and inland to east of Wiluna, Western Australia, Wiluna in the Gibson Desert. It has a total area of , and a permanent population of about 52,000 people, more than half of those in Geraldton. Earlier names The western portion of this region was known earlier as "The Murchison" based on the Murchison River (Western Australia), river of the same name, and the similarly named Goldfield. Economy The Mid West region has a diversified economy that varies with the geography and climate. Near the coast, annual rainfall of between allows intensive agriculture. Further inland, annual rainfall decreases to less than , and here the economy is dominated by mining of iron ore, gold, nickel and other mineral resources. Geraldton is an imp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 the south, the Northern Territory to the north-east, and South Australia to the south-east. Western Australia is Australia's largest state, with a total land area of . It is the second-largest country subdivision in the world, surpassed only by Russia's Sakha Republic. the state has 2.76 million inhabitants percent of the national total. The vast majority (92 percent) live in the south-west corner; 79 percent of the population lives in the Perth area, leaving the remainder of the state sparsely populated. The first Europeans to visit Western Australia belonged to the Dutch Dirk Hartog expedition, who visited the Western Australian coast in 1616. The first permanent European colony of Western Australia occurred following the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cretaceous
The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of the entire Phanerozoic. The name is derived from the Latin ''creta'', "chalk", which is abundant in the latter half of the period. It is usually abbreviated K, for its German translation ''Kreide''. The Cretaceous was a period with a relatively warm climate, resulting in high eustatic sea levels that created numerous shallow inland seas. These oceans and seas were populated with now- extinct marine reptiles, ammonites, and rudists, while dinosaurs continued to dominate on land. The world was ice free, and forests extended to the poles. During this time, new groups of mammals and birds appeared. During the Early Cretaceous, flowering plants appeared and began to rapidly diversify, becoming the dominant group of plants across the Earth b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unconformably
An unconformity is a buried erosional or non-depositional surface separating two rock masses or strata of different ages, indicating that sediment deposition was not continuous. In general, the older layer was exposed to erosion for an interval of time before deposition of the younger layer, but the term is used to describe any break in the sedimentary geologic record. The significance of angular unconformity (see below) was shown by James Hutton, who found examples of Hutton's Unconformity at Jedburgh in 1787 and at Siccar Point in 1788. The rocks above an unconformity are younger than the rocks beneath (unless the sequence has been overturned). An unconformity represents time during which no sediments were preserved in a region or were subsequently eroded before the next deposition. The local record for that time interval is missing and geologists must use other clues to discover that part of the geologic history of that area. The interval of geologic time not represented is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ordovician
The Ordovician ( ) is a geologic period and System (geology), system, the second of six periods of the Paleozoic Era (geology), Era. The Ordovician spans 41.6 million years from the end of the Cambrian Period million years ago (Mya) to the start of the Silurian Period Mya. The Ordovician, named after the Celtic Britons, Welsh tribe of the Ordovices, was defined by Charles Lapworth in 1879 to resolve a dispute between followers of Adam Sedgwick and Roderick Murchison, who were placing the same Rock (geology), rock beds in North Wales in the Cambrian and Silurian systems, respectively. Lapworth recognized that the fossil fauna in the disputed Stratum, strata were different from those of either the Cambrian or the Silurian systems, and placed them in a system of their own. The Ordovician received international approval in 1960 (forty years after Lapworth's death), when it was adopted as an official period of the Paleozoic Era by the International Union of Geological Sciences, Intern ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tumblagooda Sandstone
The Tumblagooda Sandstone is a geological formation deposited during the Silurian or Ordovician periods, between four and five hundred million years ago, and is now exposed on the west coast of Australia in river and coastal gorges near the tourist town of Kalbarri, Kalbarri National Park and the Murchison River gorge, straddling the boundary of the Carnarvon and Perth basins. Visible trackways are interpreted by some to be the earliest evidence of fully terrestrial animals. Sedimentology The Tumblagooda ranges between in thickness. The base of the formation is not exposed, but geophysical data (primarily magnetic) indicate the sandstone unconformably overlies a Proterozoic basement. The formation is divided into four ''facies associations'' (FAs), numbered stratigraphically, that occur sequentially from bottom to top. These lithified sediments portray an environment dominated by high-energy braided streams flowing into the sea; some parts have been interpreted as refl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Skolithos
''Skolithos'' (formerly spelled ''Scolithus'' or ''Skolithus'') is a common trace fossil ichnogenus that is, or was originally, an approximately vertical cylindrical burrow. It is produced by a variety of organisms in shallow marine environments globally and appear as lineated features in sedimentary rocks. Depositional environments ''Skolithos'' burrows range in age from early Cambrian to the present and are found throughout the world. They occur in sediments and sedimentary rocks, primarily sands and sandstones. They are typically marine in origin, and are commonly associated with high-energy environments close to the shoreline. They have also been reported from freshwater lacustrine settings, but have rarely been described from carbonate rocks. Vertical ''Skolithos'' burrows can also occur in alluvial sediments such as braided river deposits, where the periodic fluctuation of water is an important factor in the formation of this structure. This periodic water fluctuation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Escarpments
An escarpment is a steep slope or long cliff that forms as a result of faulting or erosion and separates two relatively level areas having different elevations. The terms ''scarp'' and ''scarp face'' are often used interchangeably with ''escarpment''. Some sources differentiate the two terms, with ''escarpment'' referring to the margin between two landforms, and ''scarp'' referring to a cliff or a steep slope. In this usage an escarpment is a ridge which has a gentle slope on one side and a steep scarp on the other side. More loosely, the term ''scarp'' also describes a zone between a coastal lowland and a continental plateau which shows a marked, abrupt change in elevation caused by coastal erosion at the base of the plateau. Formation and description Scarps are generally formed by one of two processes: either by differential erosion of sedimentary rocks, or by movement of the Earth's crust at a geologic fault. The first process is the more common type: the escarpment is a tr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
