The Archean Eon, in older sources sometimes called the Archaeozoic, is the second of the four geologic eons of Earth's history, preceded by the Hadean Eon and followed by the Proterozoic. The Archean represents the time period from 4,031 to 2,500 Mya. The Late Heavy Bombardment is hypothesized to overlap with the beginning of the Archean. The Huronian glaciation occurred at the end of the eon.
Stromatolites or stromatoliths are layered sedimentary formations (microbialite) that are created mainly by photosynthetic microorganisms such as cyanobacteria, sulfate-reducing bacteria, and Pseudomonadota. These microorganisms produce adhesive compounds that cement sand and other rocky materials to form mineral "microbial mats". In turn, these mats build up layer by layer, growing gradually over time.
The Pilbara is a large, dry, thinly populated region in the north of Western Australia. It 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.
Port Hedland is the second largest town in the Pilbara region of Western Australia, with an urban population of 15,298 as of the 2021 census, including the satellite town of South Hedland, 18 kilometres (11 mi) away. It is also the site of the highest tonnage port in Australia.
Newman, originally named Mount Newman until 1981, is a town in the Pilbara region of Western Australia. It is located about 1,186 kilometres (737 mi) north of Perth, and 9 kilometres (5.6 mi) north of the Tropic of Capricorn. It can be reached by the Great Northern Highway. Newman is a modern mining town, with homes contrasting with the surrounding reddish desert. As of the 2021 census, Newman had a population of 6,456. The Hickman Crater, a meteorite impact crater discovered in 2007, is 35 kilometres (22 mi) north of Newman.
The Mesoarchean is a geologic era in the Archean Eon, spanning 3,200 to 2,800 million years ago, which contains the first evidence of modern-style plate subduction and expansion of microbial life. The era is defined chronometrically and is not referenced to a specific level in a rock section on Earth.
The Paleoarchean, also spelled Palaeoarchaean, is a geologic era within the Archean Eon. The name derives from Greek "Palaios" ancient. It spans the period of time 3,600 to 3,200 million years ago. The era is defined chronometrically and is not referenced to a specific level of a rock section on Earth. The earliest confirmed evidence of life comes from this era, and Vaalbara, one of Earth's earliest supercontinents, may have formed during this era.
The electoral district of Pilbara is a Legislative Assembly electorate in the state of Western Australia. Pilbara is named for the region of Western Australia in which it is located. It is one of the oldest electorates in Western Australia, with its first member having been elected to the Second Parliament of the Legislative Assembly at the 1894 elections.
Vaalbara is a hypothetical Archean supercontinent consisting of the Kaapvaal Craton and the Pilbara Craton. E. S. Cheney derived the name from the last four letters of each craton's name. The two cratons consist of continental crust dating from 2.7 to 3.6 Ga, which would make Vaalbara one of Earth's earliest supercontinents.
The Pilbara Craton is an old and stable part of the continental lithosphere located in the Pilbara region of Western Australia.
Pilbara newspapers is a selection of newspapers published in the Pilbara region of Western Australia.
Ur is a hypothetical supercontinent that formed in the Archean eon around 3.1 billion years ago (Ga). In a reconstruction by Rogers, Ur is half a billion years older than Arctica and, in the early period of its existence, probably the only continent on Earth, making it a supercontinent despite probably being smaller than present-day Australia. In more recent works geologists often refer to both Ur and other proposed Archaean continental assemblages as supercratons. Ur can, nevertheless, be half a billion years younger than Vaalbara, but the concepts of these two early cratonic assemblages are incompatible.
The Warrawoona Group is a geological unit in Western Australia containing putative fossils of cyanobacteria cells. Dated 3.465 Ga, these microstructures, found in Archean chert, are considered to be the oldest known geological record of life on Earth.
Warrawoona32°42′S118°0′E is a region of Western Australia in the Pilbara province.
The Barberton Greenstone Belt of eastern South Africa contains some of the most widely accepted fossil evidence for Archean life. These cell-sized prokaryote fossils are seen in the Barberton fossil record in rocks as old as 3.5 billion years. The Barberton Greenstone Belt is an excellent place to study the Archean Earth due to exposed sedimentary and metasedimentary rocks.
The Pilbara Coast is the coastline of Western Australia's Pilbara region. It is often referred to as the North West Coast of Western Australia.
The earliest known life forms on Earth may be as old as 4.1 billion years according to biologically fractionated graphite inside a single zircon grain in the Jack Hills range of Australia. The earliest evidence of life found in a stratigraphic unit, not just a single mineral grain, is the 3.7 Ga metasedimentary rocks containing graphite from the Isua Supracrustal Belt in Greenland. The earliest direct known life on Earth are stromatolite fossils which have been found in 3.480-billion-year-old geyserite uncovered in the Dresser Formation of the Pilbara Craton of Western Australia. Various microfossils of microorganisms have been found in 3.4 Ga rocks, including 3.465-billion-year-old Apex chert rocks from the same Australian craton region, and in 3.42 Ga hydrothermal vent precipitates from Barberton, South Africa. Much later in the geologic record, likely starting in 1.73 Ga, preserved molecular compounds of biologic origin are indicative of aerobic life. Therefore, the earliest time for the origin of life on Earth is at most 3.5 billion years ago, possibly as early as 4.1 billion years ago — not long after the oceans formed 4.5 billion years ago and after the formation of the Earth 4.54 billion years ago.
Archean felsic volcanic rocks are felsic volcanic rocks that were formed in the Archean Eon. The term "felsic" means that the rocks have silica content of 62–78%. Given that the Earth formed at ~4.5 billion year ago, Archean felsic volcanic rocks provide clues on the Earth's first volcanic activities on the Earth's surface started 500 million years after the Earth's formation.
Abigail Allwood is an Australian geologist and astrobiologist at the NASA Jet Propulsion Laboratory (JPL) who studies stromatolites, detection of life on other planets, and evolution of life on early Earth. Her early work gained notability for finding evidence of life in 3.45 billion year old stromatolites in the Pilbara formation in Australia, which was featured on the cover of the journal Nature. She is now one of seven principal investigators on the Mars Rover 2020 team searching for evidence of life on Mars using the Planetary Instrument for X-Ray Lithochemistry (PIXL). Allwood is the first female and first Australian principal investigator on a NASA Mars mission.
The Dresser Formation is a Paleoarchean geologic formation that outcrops as a generally circular ring of hills the North Pole Dome area of the East Pilbara Terrane of the Pilbara Craton of Western Australia. This formation is one of many formations that comprise the Warrawoona Group, which is the lowermost of four groups that comprise the Pilbara Supergroup. The Dresser Formation is part of the Panorama greenstone belt that surrounds and outcrops around the intrusive North Pole Monzogranite. Dresser Formation consists of metamorphosed, blue, black, and white bedded chert; pillow basalt; carbonate rocks; minor felsic volcaniclastic sandstone and conglomerate; hydrothermal barite; evaporites; and stromatolites. The lowermost of three stratigraphic units that comprise the Dresser Formation contains some of the Earth's earliest commonly accepted evidence of life such as morphologically diverse stromatolites, microbially induced sedimentary structures, putative organic microfossils, and biologically fractionated carbon and sulfur isotopic data.
