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56-593: The Eastern Pilbara Craton is geologically significant due to its age and the types of lithology found within it. Within the Eastern Pilbara Craton there are 2 distinct lithologic divisions: (1), early Earth crust (3.8–3.53 Ga); (2), intrusive granitic domes along with greenstone belts (3.53–3.23 Ga). What separates this East Pilbara terrane from the rest of the Pilbara region are regional unconformities and that these rocks were once part of or deposited on

112-600: A cell-like morphology , were chemically analysed, revealing that they used sulphur for fuel. An extinct genus of stromatolite-forming cyanobacteria , Pilbaria , was named after the region, where the type specimen was found. The Pilbara region, under the Pilbara Development Commission, contains four local government areas : According to the Pilbara Aboriginal Language Centre Wangka Maya ,

168-567: A deposit thought to be located at the mouth of a river due to certain characteristics like rounded and sorted grains. Extensive field mapping and petrogenetic analysis has since shown the setting for the purported microfossils to be hydrothermal and this is widely supported. Consequently, many alternative abiotic explanations have been proposed for the filamentous microstructures including carbonaceous rims around quartz spherules and rhombs, witherite self-assembled biomorphs and haematite infilled veinlets. The carbonaceous matter composing

224-476: A movement with around 20 similar schools established in northern Western Australia by the mid-1990s. Jan Richardson , wife of Victorian Aboriginal activist Stan Davey , wrote a biography of McLeod as a doctoral thesis . In 2006, it was estimated that 15% of the population of the Pilbara identify as Aboriginal and/or Torres Strait Islander people , approximately 6000 people. Many Pilbara communities face

280-518: A number of different places. Many have poor infrastructure, and relations between police and Aboriginal people are often tense. The climate of the Pilbara is arid and tropical . It experiences high temperatures and low irregular rainfall that follows the summer cyclones . During the summer months, maximum temperatures exceed 32 °C (90 °F) almost every day, and temperatures in excess of 45 °C (113 °F) are not uncommon. Winter temperatures rarely drop below 10 °C (50 °F) on

336-403: Is about 7 every 10 years. Due to the low population density in the Pilbara region, cyclones rarely cause large scale destruction or loss of life. The area is known for its petroleum , natural gas and iron ore deposits, which contribute significantly to Australia's economy. Other than mining, pastoral activities as well as fishing and tourism are the main industries. The Pilbara's economy

392-410: Is dominated by mining exports and petroleum export industries. During the 1970s the area was known for union militancy with many strikes and some mines operating as fully unionised 'closed shops.' This was challenged by employers from the mid-1980s onwards and the region now has a very low level of union membership compared to other parts of Australia. Most of Australia 's iron ore is mined in

448-517: Is known for its Aboriginal people ; its ancient landscapes; the prevailing red earth; and its vast mineral deposits, in particular iron ore . It is also a global biodiversity hotspot for subterranean fauna . At least two important but differing definitions of "the Pilbara" region exist. Administratively it is one of the nine regions of Western Australia defined by the Regional Development Commissions Act 1993 ;

504-404: Is melted at high pressure. These rocks are critical to the formation of Archean greenstone complexes due to the low density, intrusive nature of the rocks. TTGs are found in other Archean greenstone belts such as Isua and Barberton . The processes that form TTGs are debated. Some authors attribute TTG formation to subduction activity, while others attribute the origin of these melts to

560-723: Is one of only two pristine Archaean 3.8–2.7 Ga (billion years ago) crusts identified on the Earth, along with the Kaapvaal Craton in South Africa . The youngest rocks are 1.7 Ga old in the historic area assigned to the Craton. Both locations may have once been part of the Vaalbara supercontinent or the continent of Ur . There are two subregional geographical classification regimes used, being: The most important part of

616-711: Is the Roebourne coastal sandplain, which supports most of the region's population in towns and much of its industry and commerce. The eastern third is almost entirely desert, and is sparsely populated by a small number of Aboriginal people. The two areas are separated by the inland uplands of the Pilbara Craton , including the predominant Hamersley Range , which has numerous mining towns, the Chichester Range , and others. The uplands have many gorges and other natural attractions. The Pilbara contains some of

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672-552: The Australian Bureau of Agricultural and Resource Economics , as of 2010 , that resource is being used up at a rate of 324 million tonnes a year, with rates expected to increase over coming years. Experts Gavin Mudd ( Monash University ) and Jonathon Law ( Commonwealth Scientific and Industrial Research Organisation ) expect it to be gone within 30 to 50 years (Mudd) and 56 years (Law). As of 2010 , active iron ore mines in

728-670: The Manyjilyjarra language and "mingkirri" in the Warlpiri language ) which are circular patches of land barren of plants, varying between 2 and 12 metres (7 and 39 ft) in diameter and often encircled by a ring of stimulated growth of grass, are found in the western part of the Great Sandy Desert in the Pilbara. It has not yet been proven what causes these formations, but one theory suggests that they have been built and inhabited by Australian harvester termites since

784-507: The Pleistocene . The Pilbara is home to a wide variety of endemic species adapted to this tough environment. There is a high diversity of invertebrates, including hundreds of species of subterranean fauna (both stygofauna and troglofauna ), which are microscopic invertebrates that live in caves, vugs or groundwater aquifers of the region, and terrestrial fauna (see short-range endemic invertebrates ). The Pilbara olive python ,

840-546: The earliest known life on land may have been found in 3.48-billion-year-old geyserite and other related mineral deposits (often found around hot springs and geysers ) uncovered in the Dresser Formation in the Pilbara Craton. Biogenic sedimentary structures (microbialites) such as stromatolites and MISS were described from tidal, lagoonal and subtidal coastal settings that can be reconstructed from

896-442: The greenstone at the bottom of the syncline experiences the most deformation. As seen in the figure, this process can be described in a simplified version, through 2 stages. In stage 1, heat being radiated from the partially melted granite rising is insulated by the cold greenstone cover, and as a result, the greenstone at the bottom of the formation begins to "drip" down, making room for the granitic to rise further. In stage 2,

952-497: The rangeland livestock (grazing/pastoral) industry or pearling ports . However, as natural mother of pearl beds around Cossack were fished out, the pearling fleet began to move northward, and by 1883 it was based at Broome, in the Kimberley region. From c.  1900 , pastoralism went into decline with the growth of other, more productive agricultural areas of the state. Mining in the region started on 1 October 1888, when

1008-562: The western pebble-mound mouse , and the Pilbara ningaui of the Hamersley Range are among the many species of animals within the fragile ecosystems of this desert ecoregion. Birds include the Australian hobby , nankeen kestrel , spotted harrier , mulga parrot and budgerigars . Wildlife has been damaged by the extraction of iron, natural gas and asbestos, but the protection of culturally and environmentally sensitive areas of

1064-521: The 3.47 billion year-old Mount Ada Basalt, a rock layer that is a few million years older than the Apex chert. However, the biogenicity of these supposed fossils has also been disputed, with some studies finding abiotic processes to be a more likely culprit for their formation. Additional potential bioindicators from the Precambrian have been found in the region, including carbonaceous microfossils in

1120-582: The Dresser stratigraphy as well. The rocks of the Dresser Formation display evidence of haematite alteration that may have been microbially influenced. The earliest direct evidence of life on Earth may be fossils of microorganisms permineralized in 3.465-billion-year-old Australian Apex chert rocks. However, the evidence for the biogenicity of these microstructures has been thoroughly debated. Originally, 11 taxa were described from

1176-472: The Fortescue, Hamersley, and Turee Creek basins that are usually aged from 2.78–2.42 billion years old and the younger volcano-sedimentary Ashburton Basin aged from 2.21–1.79 billion years ago. A surface region between the Fortescue and Hamersley basins is even younger, at less than 1.7 billion years old, as are the surrounding geo-ecosystems surface rocks to the Pilbara Craton. It is important to note that to

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1232-557: The Pilbara Craton to understand the early Earth crust is called the Eastern Pilbara Craton , where still exposed today, are crustal rocks that are up to 3.8 billion years old and intrusive granitic domes along with greenstone belts that are about 3.5 to 3.2 billion years old. The geology was reassessed in 2007 with the separation out from the geologically named Pilbara Craton of a thick succession of interbedded clastic or chemical sedimentary rocks and volcanic rocks forming

1288-538: The Pilbara Goldfield was officially declared – named after a local creek, the goldfield would later give its name to the region as a whole. It was later divided into the Nullagine Goldfield and Marble Bar Goldfield. However, gold mining began to decline in the Pilbara in the mid-1890s, after alluvial ore had been exhausted. In 1937, mining of asbestos commenced at Wittenoom Gorge . While

1344-636: The Pilbara are: A significant part of Pilbara's economy is based on liquified natural gas (LNG) through the North West Shelf Venture and Pluto LNG plant, both operated by Woodside. The region also has a number of cattle-grazing stations, and a substantial tourist sector, with popular natural attractions including the Karijini and Millstream-Chichester national parks and the Dampier Archipelago . The first railway in

1400-553: The Pilbara coast. The Aboriginal population of the Pilbara considerably predates, by 30,000 to 40,000 years, the European colonisation of the region. Archaeological evidence indicates that people were living in the Pilbara even during the harsh climatic conditions of the Last Glacial Maximum . The early history of the first people is held within an oral tradition , archeological evidence and petroglyphs . Near

1456-658: The Pilbara is now enhanced by the delineation of several protected areas, including the Millstream-Chichester and the Karijini National Parks . The western Pilbara is part of the Pilbara freshwater ecoregion , also known as the Pilbara-Gascoyne or Indian Ocean drainage basin. The freshwater region is characterized by intermittent rivers which form deep gorges, and brackish-water caves that host endemic species. The region includes

1512-592: The Pilbara region around 1900 have been described as slavery , with no wages paid, kidnapping as well as severe and cruel punishments for misbehaviour and absconding all common practices. Some incidents, such as the Bendu Atrocity of 1897, attracted international condemnation. The first strike by Indigenous people in Australia took place in 1946 in the Pilbara, known as the Pilbara strike or Pilbara Aboriginal strike, when Aboriginal pastoral workers walked off

1568-511: The Pilbara region was the narrow-gauge Marble Bar Railway between Port Hedland and Marble Bar . The Marble Bar Railway opened in July 1911 and closed in October 1951. The Roebourne-Cossack Tramway opened in 1897 and many industrial railways have been built to serve the mines. Five heavy-duty railways are associated with the various iron-ore mines. They are all standard gauge and built to

1624-416: The Pilbara's rainfall occurs between December and May, usually with occasional heavy downpours in thunderstorms or tropical cyclones. The period from June to November is usually completely rainless, with warm to very hot and sunny conditions. Like most of the north coast of Australia, the coastal areas of the Pilbara experience occasional tropical cyclones. The frequency of cyclones crossing the Pilbara coast

1680-399: The Pilbara, with mines mostly centred around Tom Price and Newman . The iron ore industry employs 9,000 people from the Pilbara area. The Pilbara also has one of the world's major manganese mines, Woodie Woodie, situated 400 kilometres (250 mi) southeast of Port Hedland. Iron ore deposits were first discovered by prospector Stan Hilditch, who in 1957 found a large iron ore deposit in

1736-547: The area was Francis Thomas Gregory in 1861. Within two years, European settlers had begun arriving. The region was regarded as part of the North West at first – a larger area that included the modern Kimberley and Gascoyne regions. Settlements along the coast at Tien Tsin Harbour (later Cossack), Roebourne and Condon (officially Shellborough; later abandoned) were established over ensuing decades, mainly as centres of

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1792-456: The coast; however, inland temperatures as low as 0 °C (32 °F) are occasionally recorded. The Pilbara town of Marble Bar set a world record of most consecutive days of maximum temperatures of 100 degrees Fahrenheit (37.8 degrees Celsius ) or more, during a period of 160 such days from 31 October 1923 to 7 April 1924. The average annual rainfall in the region is between 200 and 350 millimetres (7.9 and 13.8 in). Almost all of

1848-562: The combined land area of the US States of California and Indiana . It has a population of more than 45,000, most of whom live in the western third of the region, in towns such as Port Hedland , Karratha , Wickham , Newman and Marble Bar . A substantial number of people also work in the region on a fly-in/fly-out basis. There are approximately 10 major/medium population centres and more than 25 smaller ones. The Pilbara consists of three distinct geographic areas. The western third

1904-469: The creek, and the name later became associated with the region. Radiocarbon dating estimates in evidence show that rock art and standing stones at Murujuga in the Dampier Archipelago , Australia's earliest known stone structures, believably dating from 6046 to 5338 BC, are of contextualization by thousands of years of unique cultural traditions and folklore . These sites have lived up as part of survival in present times. The first European to explore

1960-424: The darker colored greenstone belts are easily seen in satellite imagery, and can also be seen in the map above. A cross-section of this structure is provided, and the steeply dipping anticlines and synclines are characteristic of this type of structure. The interior of the granitic domes are mostly undeformed, however the margins and the greenstone belts are heavily deformed, and the metamorphic grade depends on

2016-610: The direct melting of the lithosphere by mantle plumes . The debate of the origin of the TTGs is a key topic in the debate of when plate tectonics began. The structures observed in this region are interesting, and unique to areas where rocks of similar ages are found. Similar dome and keel structures are found in the Barberton Greenstone Belt . These structures were interpreted to be the result of partial convective overturn . These lighter colored domes surrounded by

2072-506: The drainages of the Murchison , Gascoyne , Ashburton , Fortescue , and De Grey rivers. The Great Sandy Desert, which covers the eastern Pilbara, has little freshwater habitat. 21°S 119°E  /  21°S 119°E  / -21; 119 Pilbara Craton The Pilbara Craton is an old and stable part of the continental lithosphere located in the Pilbara region of Western Australia . The Pilbara Craton

2128-440: The east and south of the Eastern Pilbara Craton there are significant outcrops of the very old rocks and that these are confined to the traditional area of the Pilbara Craton which is inferred to be subsurface for more than half its area. There are extensive high quality iron ore deposits and also economic to mine gold , silver , copper , nickel , lead , zinc , molybdenum , vanadium and fluorite deposits. Evidence of

2184-409: The filaments has also been repeatedly examined with Raman spectroscopy which has yielded mixed interpretations of results and is therefore regarded by many to be unreliable for determining biogenicity when used alone. Perhaps the most compelling argument to date is based on high spatial resolution electron microscopy like scanning and transmission electron microscopy . This study concludes that

2240-459: The geochemical analysis indicating that these rocks were mantle derived supports that this region was formed as a thick volcanic plateau. Partial convective overturn is a mechanism by which the geology and structure of the Pilbara Craton can be explained. This mechanism involves cold, dense material sinking into hot, less dense material as it rises in dome/pillar-like formations. This results in steeply dipping anticline–syncline complex , in which

2296-471: The granitic intrusions in the region are subvolcanic, which can be determined through the comparative chemical analysis of the intrusion and associated greenstones. All of these cycles are interpreted to be the result of successive mantle plume events. These events resulted in the overall dome (granite) and syncline (greenstone) structure of the region, which can still be seen on modern geologic maps. The overall thickness of this succession during its formation and

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2352-448: The heaviest North American standards. Rio Tinto runs driverless trains on its railways. The ports of the Pilbara are: The dominant flora of the Pilbara is acacia trees and shrubs and drought-resistant Triodia spinifex grasses. Several species of acacia (wattle) trees are endemic to the Pilbara and are the focus of conservation programs, along with wildflowers and other local specialities. " Fairy circles " (known as "linyji" in

2408-581: The many complex effects of colonisation, and lack adequate access to housing, health and education. A 1971 survey of 1000 Aboriginal people conducted by Pat McPherson found that most had one or more serious diseases. At the McClelland Royal Commission into British nuclear testing, Aboriginal people from the Pilbara provided evidence regarding the explosion on the Montebello Islands. Aboriginal communities are sited over

2464-582: The name for the Pilbara region derives from the Aboriginal word bilybara , meaning "dry" in the Nyamal and Banyjima languages. Another suggested origin is pilbarra , an Aboriginal word for the salt-water mullet found in local waters, reflected in the name of a tributary of the Yule River , Pilbarra Creek, which evolved to "Pilbara" Creek. The Pilbara Goldfield, discovered in 1885, was named after

2520-448: The nano-scale morphology of the filaments and the distribution of the carbonaceous matter are inconsistent with a biological origin for the filaments. Instead, it is more likely that the hydrothermal conditions have assisted in the heating, hydration and exfoliation of potassium micas on which barium, iron and carbonate have secondarily been adsorbed. Carbonaceous structures appearing to be of biological origin have also been discovered in

2576-633: The oldest rocks found. The dominant lithologies and associated structures in the Eastern Pilbara region are the granitic domes and greenstone belts. The granitic domes are mostly TTG or TTG-like in composition. The greenstone belts are interpreted as altered komatiitic basalts and volcanosedimentary rocks. These rocks range from ultramafic , mafic , and felsic in composition. Ultramafic rocks such as dunites can also be found. TTGs are an aggregation of certain rocks ( tonalite-trondhjemite-granodiorite ), that form when hydrous, mafic crust

2632-648: The original Pilbara Craton and are still exposed today. These groups not only differ in relative age, but also in composition. The remnants of the Archean crust in the region can be found within various granitic complexes in the Eastern Pilbara. Xenoliths of 3.58 Ga gabbroic anorthosite were found within the Shaw Granitic Complex . The Warrawagine Granitic Complex contains 3.66–3.58 Ga biotite tonalite gneiss . Presence of 3.8–3.6 Ga detrital zircons also suggests crustal erosion 300 Ma prior to

2688-543: The presence of abundant iron ore had been known for about a century, it was not until the 1960s and the discovery of high-grade ore in the Hamersley Ranges that the area became pivotal to the state's economy, and towns built to accommodate mining and allied services boomed. In the 1950s, three British nuclear weapons tests were carried out in the Montebello Islands , 130 km (81 mi) off

2744-627: The region are Port Hedland , Karratha and Newman . The three main ports in this region are Port Hedland, Dampier and Port Walcott . Under the Regional Development Commissions Act , Pilbara is situated south of the Kimberley , and comprises the local government areas of Shire of Ashburton, Shire of East Pilbara, City of Karratha Town of Port Hedland. The Pilbara region covers an area of 507,896 km (193,826 mi ) (including offshore islands), roughly

2800-504: The region's proximity to the dome-keel margins. The early history of this region was dominated by volcanic activity, magmatic intrusion and deformation. The Eastern Pilbara Terrane is mostly volcanic in nature, and this volcanic activity occurred in relatively short, and repeated cycles These ultramafic-mafic-felsic cycles which last approximately 10–15 Myr each are accompanied by metamorphism/deformation, and followed by long pauses ( approx. 75 myr) and clastic sediment deposition. Some of

2856-417: The small, sporadic greenstone drips and granitic pillars have consolidated into fewer, larger domes and keels as they continue to rise. The end result is a structural geology similar to what we see in Pilbara . This process is also known as vertical tectonics . Pilbara The Pilbara ( / ˈ p ɪ l b ər ə / ) is a large, dry, thinly populated region in the north of Western Australia . It

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2912-474: The southern Ophthalmia Range , at what was to become the Mount Whaleback mine . In the 1960s, it was reportedly called "one of the most massive ore bodies in the world" by Thomas Price, then vice president of US-based steel company Kaiser Steel. Geoscience Australia calculated that the country's " economic demonstrated resources " of iron amounted to 24 gigatonnes, or 24 billion tonnes. According to

2968-489: The stations in protest at low pay and bad working conditions, a strike that lasted for over three years. Family clans in the Pilbara who were supported by mining prospector, Don McLeod , developed skills for mining and the concentration of rare metals . For a short period money accumulated, which according to Aboriginal law was to be used for traditional ways. Eventually the funds were used to establish an independent Aboriginal-controlled school. The concept has expanded into

3024-731: The term also refers to the Pilbara shrublands bioregion (which differs in extent) under the Interim Biogeographic Regionalisation for Australia (IBRA). The Pilbara region, as defined by the Regional Development Commissions Act 1993 and administered for economic development purposes by the Pilbara Development Commission, has an estimated population of 61,688 as of June 2018 , and covers an area of 507,896 square kilometres (196,100 sq mi). It contains some of Earth's oldest rock formations , and includes landscapes of coastal plains and mountain ranges with cliffs and gorges. The major settlements of

3080-412: The town of Dampier is a peninsula known as Murujuga , which contains a large collection of World Heritage-listed petroglyphs, dating back thousands of years. Rock art in the Pilbara appears to have been mainly etched into the hard rock surfaces, whereas on the softer sandstone in the Kimberley rock paintings predominate. Working conditions in the pearling and pastoral industries for Aboriginal people in

3136-420: The world's oldest surface rocks, including the ancient fossilised remains known as stromatolites and rocks such as granites that are more than three billion years old. In 2007, some of the oldest evidence of life on Earth was found in 3.4 billion-year-old sandstones at Strelley Pool , which preserve fossils of sulphur -processing bacteria. The mineralised spheres, which were found on an ancient beach and have

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