The Jack Hills are a range of hills in Mid West Western Australia . They are best known as the source of the oldest material of terrestrial origin found to date: Hadean zircons that formed around 4.404 billion years ago. These zircons have enabled deeper research into the conditions on Earth in the Hadean eon. Potentially biogenic carbon isotope ratios have been identified for graphite embedded within a 4.1 billion-year-old zircon from the site.
20-721: They are located on the border of the Shire of Murchison and the Shire of Meekatharra , south of the Murchison River , about 800 kilometres (500 mi) north of Perth . The Jack Hills are located in the Narryer Gneiss Terrane of the Yilgarn Craton , Western Australia , and comprise an 80 kilometres (50 mi) long northeast-trending belt of folded and metamorphosed supracrustal rocks . Sedimentary siliciclastic rocks, interpreted as alluvial fan - delta deposits, are
40-521: A 4,404 ± 8 million year old zircon was found at Erawandoo Hill; this is the oldest dated material originating on Earth; the date is in the Cryptic era of the Hadean eon. They were found within a unit of the supracrustal sequence, a metamorphosed conglomerate considered to have an age ~3.0 Ga. Given the detrital nature of the rock unit, the zircons are sourced from pre-existing rocks which were then weathered and
60-441: A few other houses and an Australia Post Community Postal Agent (CPA). Murchison Shire Airport ( ICAO airport code : YMSS ), which adjoins the townsite, has a 1,448 metre all-weather runway . The shire is represented by 7 councillors, and has been divided into two wards. The shire president is elected from among the councillors. Prior to 2005, there were 4 wards – Boolardy, Byro, Mileura and Yallalong. The localities of
80-735: A proposed array of radio telescope receivers with a total collecting area of one square kilometre. It is already home to two other major radio telescope facilities: the Murchison Widefield Array and the Australian Square Kilometre Array Pathfinder . The Square Kilometre Array, or SKA, is a global radio telescope project involving institutions in more than 20 countries. The SKA will be the largest and most capable radio telescope ever constructed—50 times more sensitive than any other radio instrument. Australia and southern Africa will each host different components of
100-533: A reference, and/or with a substantial contribution to the development of geological sciences through history.' 26°07′S 117°09′E / 26.117°S 117.150°E / -26.117; 117.150 Shire of Murchison The Shire of Murchison is a 49,500 km² local government area (LGA), within the Murchison sub-region , in the Mid West region of Western Australia . Encompassing most of
120-486: A small part of the Murchison locality . The Shire of Murchison incorporates 29 pastoral stations and a population of 114 . Most properties are operated by family units with their main income from cattle, meat sheep and wool, with some goats. A small tourism industry is developing in the region with some stations involved in station stays and with the Murchison Oasis Caravan Park and motel units located at
140-558: A water ocean; also contrasting with earlier ideas on Earth's history . The hypothesis of humid and cool conditions before the Late Heavy Bombardment has been promoted as cool early Earth . The Jack Hills banded iron formation (BIF) is the site of a non-operating minor iron ore mine owned by Mitsubishi Development Pty Ltd, a wholly owned subsidiary of Mitsubishi Corporation , which in the past exported up to 3 million tonnes per annum of high grade detrital hematite iron ore via
160-459: Is a multiple of the square metre , the SI unit of area or surface area . 1 km is equal to: It is also approximately equal to: Conversely: The symbol "km " means (km) , square kilometre or kilometre squared and not k(m ), kilo–square metre. For example, 3 km is equal to 3 × (1,000 m) = 3,000,000 m , not 3,000 m . Topographical map grids are worked out in metres, with
180-476: The Shire of Northampton were incorporated into Murchison. In 1966, a new shire office, including a residence for the shire clerk was built, approximately 200 km north of Mullewa on the Carnarvon to Mullewa Road. In 1985, a roadhouse was built nearby and additional shire buildings, including a museum. The area surrounding the shire complex was gazetted as Murchison Settlement in 1988. It has come to include
200-476: The Murchison and East Murchison goldfields, the shire is named after the Murchison River . It is Australia's least-populated LGA and the only one without an official town. Five sparsely-populated rural localities , with a collective population of 101 (as of 2021), comprise the entire shire. The shire offices, located 300 kilometres (186 mi) northeast of Geraldton , are the focal point of Murchison Settlement,
220-1105: The SKA. Management of the facilities at the SKA is coordinated by the CSIRO from the offices and laboratories at the Murchison Radio-astronomy Support Facility in Geraldton. As of 2023, 35 places are heritage-listed in the Shire of Murchison, of which four are on the State Register of Heritage Places , among them the Boolardy Homestead . The homestead, dating back to 1875, was added to the state register on 29 May 2001. 26°53.61′S 115°57.39′E / 26.89350°S 115.95650°E / -26.89350; 115.95650 Square kilometre The square kilometre ( square kilometer in American spelling; symbol: km )
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#1732845010236240-545: The Shire of Murchison with population and size figures based on the most recent Australian census : The Shire is the site of the Murchison Radio-astronomy Observatory, which lies 70 km east-northeast of Murchison Settlement. A sparse population – and its consequent radio "quietness" – is a factor behind the Shire being selected as one of the two sites for the Square Kilometre Array –
260-544: The base). The Murchison Road District was gazetted on 3 August 1875. It absorbed the Upper Murchison Road District on 18 March 1912. On 1 July 1961 it became the Shire of Murchison following changes to the Local Government Act, which reformed all remaining road districts into shires. In 2004 the shire was expanded in area when the northern part of the Shire of Mullewa and an eastern section of
280-558: The grid lines being 1,000 metres apart. In each case, the grid lines enclose one square kilometre. The area enclosed by the walls of many European medieval cities were about one square kilometre. These walls are often either still standing or the route they followed is still clearly visible, such as in Brussels , where the wall has been replaced by a ring road, or in Frankfurt , where the wall has been replaced by gardens. The approximate area of
300-565: The major lithology. Minor mafic / ultramafic rocks and banded iron formation (BIF) are also found in the sequence. The overall sequence is generally considered to be a granulite gneiss, which has undergone multiple deformations and multiple metamorphic episodes. The protolith age of the Narryer Gneiss Terrane is variable, but generally considered to be in excess of 3.6 Ga (billion years). Detrital zircons with ages greater than 4 billion years old have been found in these rocks, and
320-399: The old walled cities can often be worked out by fitting the course of the wall to a rectangle or an oval ( ellipse ). Examples include: Parks come in all sizes; a few are almost exactly one square kilometre in area. Here are some examples: Using the figures published by golf course architects Crafter and Mogford, a course should have a fairway width of 120 metres and 40 metres clear beyond
340-546: The oldest terrestrial crystals known to exist on Earth', the International Union of Geological Sciences (IUGS) included the 'Archean zircons of Erawondoo Hill' in its assemblage of 100 'geological heritage sites' around the world in a listing published in October 2022. The organisation defines an IUGS Geological Heritage Site as 'a key place with geological elements and/or processes of international scientific relevance, used as
360-550: The port of Geraldton . Other companies operating in the area are also planning major magnetite BIF-based iron ore mines. Due to its importance as a geology research site, part of the Jack Hills is included on the Australian National Heritage List . It was nominated for listing in 2003, received an interim listing in 2009, and a permanent listing in 2020. In respect of being the 'largest in situ repository of
380-466: The resultant sediment deposited as sedimentary rock. The zircons and various aspects of their geochemistry provide evidence for the existence of continental-type crust on the surface of Earth during the Hadean eon, contrasting with earlier ideas on the earliest phase of Earth's history . Additionally, oxygen isotopic ratios in the zircons provide evidence for the presence of liquid water on the surface, if not
400-483: The settlement providing facilities for tourists. The Shire of Murchison takes its name from the Murchison River , which was named in 1839 by explorer George Grey after Sir Roderick Impey Murchison , President of the Royal Geographical Society of London . The Shire’s logo is based on the coat of arms of his family, Murchison of Tarradale ( lion rampant between two pineapples with a scallop shell at
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