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64-470: The Williston Basin lies above an ancient Precambrian geologic basement feature, the Trans-Hudson Orogenic Belt that developed in this area about 1.8-1.9 billion years ago, and that created a weak zone that later led to sagging to produce the basin. The Precambrian basement rocks in the center of the basin beneath the city of Williston, North Dakota lie about 16,000 feet (4,900 m) below

128-697: A supereon , but this is also an informal term, not defined by the ICS in its chronostratigraphic guide. Eozoic (from eo- "earliest") was a synonym for pre-Cambrian , or more specifically Archean . A specific date for the origin of life has not been determined. Carbon found in 3.8 billion-year-old rocks (Archean Eon) from islands off western Greenland may be of organic origin. Well-preserved microscopic fossils of bacteria older than 3.46 billion years have been found in Western Australia . Probable fossils 100 million years older have been found in

192-429: A "relatively new semi-surface and semi-underground coal mining method that evolved from auger mining". In highwall mining, the coal seam is penetrated by a continuous miner propelled by a hydraulic pushbeam transfer mechanism (PTM). A typical cycle includes sumping (launch-pushing forward) and shearing (raising and lowering the cutterhead boom to cut the entire height of the coal seam). As the coal recovery cycle continues,

256-433: A controlled water-inflow pump system and/or a gas (inert) venting system. Recovery with tunneling shape of drives used by highwall miners is much better than round augering holes, but the mapping of areas that have been developed by a highwall miner are not mapped as rigorously as deep mined areas. Very little soil is displaced in contrast with mountaintop removal; however, it is comparatively more expensive to own and operate

320-437: A highwall miner. Mapping of the outcrop, as well as core hole data and samples taken during the bench-making process, are taken into account to best project the panels that the highwall miner will cut. Obstacles that could be potentially damaged by subsidence and the natural contour of the highwall mine are taken into account, and a surveyor points the highwall miner in a line (theoretical survey plot-line) mostly perpendicular to

384-556: A long strip of overlying soil and rock (the overburden ); this activity is also referred to as overburden removal . It is most commonly used to mine coal and lignite (brown coal) . Strip mining is only practical when the ore body to be excavated is relatively near the surface and/or is mostly horizontal. This type of mining uses some of the largest machines on earth, including bucket-wheel excavators which can move as much as 12,000 cubic meters (16,000 cu. yd.) of earth per hour. There are two forms of strip mining. The more common method

448-684: A major oil province until the 1950s when large fields were discovered in North Dakota. Amerada Corporation began the search in 1946. After four years of testing and mapping they started drilling at a promising lease 30 miles north-east of Williston, North Dakota , and on April 4, 1951, discovered oil on the Nesson Anticline, with the Amerada Hess Corporation Clarence Iverson #1 well. Other oil firms rushed in to buy up leases on farm land to explore for oil and by 1954 80% of

512-476: A number of effects on the local environment. The negative effects involve soil, water, air, and noise pollution as well as landscape alteration and various other negatives. However, new technology and proper management can make it easier to properly treat the local water supply and restore the local ecology which helps rebuild the environment. Each type of surface mining has its own environmental impact, as laid out below. Strip mining - Once operations have ended,

576-402: A once operational surface mine requires a large sum of money and extensive environmental remediation . These remediation projects can continue on for years after the mine is closed. In some cases, the mining companies go bankrupt leaving abandoned mines with no funding for remediation. In other cases, mining companies are unwilling to pay for remediation, meaning litigation or regulatory action

640-713: A possible 2450 Ma red alga from the Kola Peninsula , 1650 Ma carbonaceous biosignatures in north China, the 1600 Ma Rafatazmia , and a possible 1047 Ma Bangiomorpha red alga from the Canadian Arctic. The earliest fossils widely accepted as complex multicellular organisms date from the Ediacaran Period. A very diverse collection of soft-bodied forms is found in a variety of locations worldwide and date to between 635 and 542 Ma. These are referred to as Ediacaran or Vendian biota . Hard-shelled creatures appeared toward

704-545: A region of the United States with numerous endemic species . Erosion also increases, which can intensify flooding . In the eastern United States, the Appalachian Regional Reforestation Initiative works to promote the use of trees in mining reclamation. Dredging is a method for mining below the water table. It is mostly associated with gold mining. Small dredges often use suction to bring

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768-508: A region where flat land is rare. They also maintain that the new growth on reclaimed mountaintop mined areas is better able to support populations of game animals. Critics contend that mountaintop removal is a disastrous practice that benefits a small number of corporations at the expense of local communities and the environment . A U.S. Environmental Protection Agency (EPA) environmental impact statement finds that streams near valley fills sometimes may contain higher levels of minerals in

832-424: A variety of health risks caused by mining such as different cardiovascular diseases, food, and water contamination. Habitat destruction , alongside air, noise, and water pollution, are all significant negative environmental impacts caused by the side effects of surface mining. There are five main types of surface mining as detailed below. Strip mining is the practice of mining a seam of mineral, by first removing

896-401: Is area stripping , which is used on fairly flat terrain, to extract deposits over a large area. As each long strip is excavated, the overburden is placed in the excavation produced by the previous strip. Contour mining involves removing the overburden above the mineral seam near an outcrop in hilly terrain, where the mineral outcrop usually follows the contour of the land. Contour stripping

960-453: Is a health hazard. Although MTR sites are required to be reclaimed after mining is complete, reclamation has traditionally focused on stabilizing rock and controlling erosion, but not always on reforesting the area. Quick-growing, non-native grasses, planted to quickly provide vegetation on a site, compete with tree seedlings, and trees have difficulty establishing root systems in compacted backfill. Consequently, biodiversity suffers in

1024-651: Is known to occur during the RNA replication of extant coronaviruses . Evidence of the details of plate motions and other tectonic activity in the Precambrian is difficult to interpret. It is generally believed that small proto-continents existed before 4280 Ma, and that most of the Earth's landmasses collected into a single supercontinent around 1130 Ma. The supercontinent, known as Rodinia , broke up around 750 Ma. A number of glacial periods have been identified going as far back as

1088-443: Is often followed by auger mining into the hillside, to remove more of the mineral. This method commonly leaves behind terraces in mountainsides. Open-pit mining refers to a method of extracting rock or minerals from the earth through their removal from an open pit or borrow . This process is done on the ground surface of the earth It is best suited for accessing mostly vertical deposits of minerals. Although open-pit mining

1152-458: Is regulated by state and local laws, which may vary widely. The National Environmental Policy Act (NEPA), Resource Conservation and Recovery Act (RCRA), Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) and many more laws deal with the subject of surface mining. In some cases, even with proper legislation in place for surface mining some negative human health and environmental impacts remain. Surface mining can have

1216-458: Is sometimes mistakenly referred to as "strip mining", the two methods are different (see above). Mountaintop removal mining (MTR) is a form of coal mining that mines coal seams beneath mountaintops by first removing the mountaintop overlying the coal seam. Explosives are used to break up the overburden (rock layers above the seam), which is then removed. The overburden is then dumped by haul trucks into fills in nearby hollows or valleys. MTR involves

1280-651: Is the earliest part of Earth's history , set before the current Phanerozoic Eon. The Precambrian is so named because it preceded the Cambrian , the first period of the Phanerozoic Eon , which is named after Cambria , the Latinized name for Wales , where rocks from this age were first studied. The Precambrian accounts for 88% of the Earth's geologic time. The Precambrian is an informal unit of geologic time, subdivided into three eons ( Hadean , Archean , Proterozoic ) of

1344-514: Is thought that the Earth coalesced from material in orbit around the Sun at roughly 4,543 Ma, and may have been struck by another planet called Theia shortly after it formed, splitting off material that formed the Moon (see Giant-impact hypothesis ). A stable crust was apparently in place by 4,433 Ma, since zircon crystals from Western Australia have been dated at 4,404 ± 8 Ma. The term "Precambrian"

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1408-457: Is thought to have formed about 1300-900 Ma, to have included most or all of Earth's continents and to have broken up into eight continents around 750–600 million years ago. Strip-mining Surface mining , including strip mining , open-pit mining and mountaintop removal mining , is a broad category of mining in which soil and rock overlying the mineral deposit (the overburden ) are removed, in contrast to underground mining , in which

1472-693: Is used by geologists and paleontologists for general discussions not requiring a more specific eon name. However, both the United States Geological Survey and the International Commission on Stratigraphy regard the term as informal. Because the span of time falling under the Precambrian consists of three eons (the Hadean , the Archean , and the Proterozoic ), it is sometimes described as

1536-485: Is very sensitive and vulnerable to drastic and harmful changes within their ecosystem. Highwall mining - Has a lower environmental impact than mountaintop removal because of the smaller external surface area present but there are still negative side effects. Air and noise pollution from blasting are common environmental effects along with the large tailing piles, which can leach into waterways and numerous ecosystems. Properly cleaning, restoring, and removing hazards from

1600-462: The Appalachian coal fields of West Virginia , Kentucky , Virginia , and Tennessee in the United States. The profound changes in topography and disturbance of pre-existing ecosystems have made mountaintop removal highly controversial. Advocates of mountaintop removal point out that once the areas are reclaimed as mandated by law, the technique provides premium flat land suitable for many uses in

1664-523: The Bakken Formation . Cumulative basin production totals about 3.8 billion barrels (600,000,000 m) of oil and 470 billion cubic feet (1.3 × 10 m) of natural gas. The largest oil fields are listed in the following table, showing estimated ultimate recoveries. Potash produced from the Williston Basin makes Canada the world's leading producer of that commodity. The deposits occur in

1728-521: The Huronian epoch, roughly 2400–2100 Ma. One of the best studied is the Sturtian-Varangian glaciation, around 850–635 Ma, which may have brought glacial conditions all the way to the equator, resulting in a " Snowball Earth ". The atmosphere of the early Earth is not well understood. Most geologists believe it was composed primarily of nitrogen, carbon dioxide, and other relatively inert gases, and

1792-596: The Middle Devonian Prairie Formation . Major potash-producing companies include Nutrien and Mosaic . The Williston Basin holds large coal deposits, primarily in the Fort Union Formation of mostly Paleogene age, and were first noted during the Lewis and Clark Expedition . Mining of the coal began in 1873 near Sims, North Dakota , but was soon abandoned. The Northern Pacific Railway took over

1856-426: The coal mined in the United States . In most forms of surface mining, heavy equipment , such as earthmovers, first remove the overburden. Next, large machines, such as dragline excavators or bucket-wheel excavators , extract the mineral. Advantages of surface mining include lower cost and greater safety compared to underground mining. Disadvantages include hazards to human health and the environment. Humans face

1920-511: The geologic time scale . It spans from the formation of Earth about 4.6 billion years ago ( Ga ) to the beginning of the Cambrian Period, about 538.8 million years ago ( Ma ), when hard-shelled creatures first appeared in abundance. Relatively little is known about the Precambrian, despite it making up roughly seven-eighths of the Earth's history , and what is known has largely been discovered from

1984-482: The oxygen catastrophe . At first, oxygen would have quickly combined with other elements in Earth's crust, primarily iron, removing it from the atmosphere. After the supply of oxidizable surfaces ran out, oxygen would have begun to accumulate in the atmosphere, and the modern high-oxygen atmosphere would have developed. Evidence for this lies in older rocks that contain massive banded iron formations that were laid down as iron oxides. A terminology has evolved covering

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2048-593: The tailings are placed back into the hole and covered up to make the site resemble the landscape before the mining operation. This process involves the removal of all ground vegetation in the area, which is a detriment to the environment. Topsoil may be placed over the tailing along with planting trees and other vegetation. Another reclamation method involves filling in the hole with water to create an artificial lake. Large tailing piles left behind may contain heavy metals which can leach out acids such as lead and copper and enter into water systems. Open-pit mining - One of

2112-401: The 1960s onwards. The Precambrian fossil record is poorer than that of the succeeding Phanerozoic , and fossils from the Precambrian (e.g. stromatolites ) are of limited biostratigraphic use. This is because many Precambrian rocks have been heavily metamorphosed , obscuring their origins, while others have been destroyed by erosion, or remain deeply buried beneath Phanerozoic strata. It

2176-852: The Red River is the Ordovician Stony Mountain Formation and Stonewall Formation , followed by the Silurian Interlake Group . During the Devonian , the Williston Basin became the southeastern corner of the Elk Point Basin when the Elk Point Group , Manitoba Group , and Saskatchewan Group were deposited. The Bakken Formation , an organic-rich marine shale , was deposited in the Late Devonian. The Lodgepole Limestone

2240-495: The Williston Basin included deposition of rocks well suited to serve as hydrocarbon source and reservoir rocks . The basin's oil and gas fields are found in a wide range of geologic ages, as indicated by the generalized stratigraphic column. In 1913, shallow gas was discovered in an Upper Cretaceous sandstone on the Cedar Creek Anticline , and oil was discovered on the same anticline in 1936. The basin did not become

2304-696: The coal seam, and today's models are capable of going farther, with the support of gyro navigation and not limited anymore by the amount of cable stored on the machine. The maximum depth would be determined by the stress of further penetration and associated specific-power draw (torsion and tension in screw transporters string), but today's optimized screw-transporters conveying embodiments (called pushbeams) with visual product development and discrete element modeling (DEM) using flow simulation behavior software shows smart-drive extended penetrations are possible, even so under steep inclined angles from horizontal to more than 30 degree downhole. In case of significant steep mining

2368-401: The current scheme based upon numerical ages. Such a system could rely on events in the stratigraphic record and be demarcated by GSSPs . The Precambrian could be divided into five "natural" eons, characterized as follows: The movement of Earth's plates has caused the formation and break-up of continents over time, including occasional formation of a supercontinent containing most or all of

2432-560: The cutterhead is progressively launched into the coal seam for 19.72 feet (6.01 m). Then, the PTM automatically inserts a 19.72-foot-long (6.01 m) rectangular pushbeam (screw-conveyor segment) into the center section of the machine between the Powerhead and the cutterhead. The pushbeam system can penetrate nearly 1,200 feet (370 m) (proven in 2015 till today) into the coal seam. One patented highwall mining system uses augers enclosed inside

2496-453: The early years of the Earth's existence, as radiometric dating has allowed absolute dates to be assigned to specific formations and features. The Precambrian is divided into three eons: the Hadean (4567.3–4031 Ma), Archean (4031-2500 Ma) and Proterozoic (2500-538.8 Ma). See Timetable of the Precambrian . It has been proposed that the Precambrian should be divided into eons and eras that reflect stages of planetary evolution, rather than

2560-691: The end of that time span, marking the beginning of the Phanerozoic Eon. By the middle of the following Cambrian Period, a very diverse fauna is recorded in the Burgess Shale , including some which may represent stem groups of modern taxa. The increase in diversity of lifeforms during the early Cambrian is called the Cambrian explosion of life. While land seems to have been devoid of plants and animals, cyanobacteria and other microbes formed prokaryotic mats that covered terrestrial areas. Tracks from an animal with leg-like appendages have been found in what

2624-426: The environmental impacts are primarily found underwater. The method of extracting material from the seafloor or any water body leads to the harmful risk of marine life. Overall, the effect are far less compared to the other mining methods. The influx of sediment can bury flora and fauna, change water levels and can alter the oxygen content. Water and noise pollution is a concern that must be monitored because marine life

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2688-650: The formation a distinctive green color. The basin started subsiding due to strike-slip movement along northeast–southwest trending faults , resulting in the deposition of the Winnipeg Group, which lies unconformably on the Deadwood. The Winnipeg consists of shallow marine sandstone, shale and shaly carbonate . The Red River Formation lies unconformably on the Winnipeg, and consists of shallow marine carbonate, anhydrite , and salt sedimentation . Conformably overlying

2752-473: The highest concentration. The helium originated through natural radioactive decay of uranium and thorium in Precambrian granitic basement rocks, or Lower Paleozoic shales . The Upper Cambrian Deadwood Formation was transgressively deposited on the low-relief Precambrian surface. The Deadwood is characterized by shallow marine and coastal plain sediments, with abundant glauconite giving

2816-503: The highwall. parallel lines represent the drive cut into the mountain (up to 1,200 feet (370 m) deep (2015 records), without heading or corrective steering actuation on a navigation azimuth during mining results in missing a portion of the coal seam and is a potential danger of cutting in pillars from previous mined drives due to horizontal drift (roll) of the pushbeam-cuttermodule string. Recently highwall miners have penetrated more than 1,200 feet (370 m) (2015 ongoing records into

2880-541: The landmass. The earliest known supercontinent was Vaalbara . It formed from proto-continents and was a supercontinent 3.636 billion years ago. Vaalbara broke up c. 2.845–2.803 Ga ago. The supercontinent Kenorland was formed c. 2.72 Ga ago and then broke sometime after 2.45–2.1 Ga into the proto-continent cratons called Laurentia , Baltica , Yilgarn craton and Kalahari . The supercontinent Columbia , or Nuna, formed 2.1–1.8 billion years ago and broke up about 1.3–1.2 billion years ago. The supercontinent Rodinia

2944-462: The loose sediment in a pond of its own making. Highwall mining is another form of mining sometimes conducted to recover additional coal adjacent to a surface-mined area. The method evolved from auger mining but does not meet the definition of surface mining since it does not involve the removal of overburden to expose the coal seam. CERB final report No. 2014-004 "Highwall Mining: Design Methodology, Safety, and Suitability" by Yi Luo characterizes it as

3008-928: The mass restructuring of earth in order to reach coal seams as deep as 400 feet (120 m) below the surface. Mountaintop removal replaces the original steep landscape with a much flatter topography. Economic development attempts on reclaimed mine sites include prisons such the Big Sandy Federal Penitentiary in Martin County, Kentucky , small-town airports, golf courses such as Twisted Gun in Mingo County, West Virginia and Stonecrest Golf Course in Floyd County, Kentucky , as well as industrial scrubber sludge disposal sites, solid waste landfills, trailer parks, explosive manufacturers, and storage rental lockers. This method has been increasingly used in recent years in

3072-747: The mine and developed the lignite beds as the Northern Pacific Coal Company. Other mines followed near Minot, North Dakota and Dickinson, North Dakota , and the period from 1900 to 1920 saw a large-scale increase in the lignite industry. Strip-mining was common from 1920 until 1940, and 320 mines were in operation by 1940. However, production peaked in 1951, and by 1965, only 38 mines were in operation, while by 1999, only 4. In 1952, helium concentrations were discovered in southwestern Saskatchewan. Production from four wells took place from 1963 to 1977, and resumed again in 2014. The Deadwood Formation, and other Lower Paleozoic formations, had

3136-439: The mined material up from the bottom of a water body. Historical large-scale dredging operations often used a floating dredge; a barge-like vessel that scoops material up through a conveyor belt on the bow, filters out the desired component on board, and returns the unwanted material to the water via another conveyor belt on the stern. In gravel-filled river valleys with shallow water tables, a floating dredge can work its way through

3200-449: The new mining method phrase should be "directional mining" (commonly used technologies as valuable synergy directional drilling and directional mining are categorized in "surface to in-seam" (SIS) techniques), dry or wet, dewatering is developed or cutting and dredging through screw transporters are proactive in developing a roadmap of the leading global highwall mining engineering company. Historically, moving materials out of surface mines

3264-417: The overlying rock is left in place, and the mineral is removed through shafts or tunnels. In North America, where the majority of surface coal mining occurs, this method began to be used in the mid-16th century and is practiced throughout the world in the mining of many different minerals. In North America, surface mining gained popularity throughout the 20th century, and surface mines now produce most of

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3328-463: The possible oil producing areas were under lease. Royal Dutch Shell at that time had leases on over 8 million acres. Many local farmers and area speculators became instant millionaires, leasing land at an average of $ 25 an acre and then selling those leases back at a much higher cost per acre. Production peaked in 1986, but in the early 2000s significant increases in production began because of application of horizontal drilling techniques, especially in

3392-534: The pushbeam that prevent the mined coal from being contaminated by rock debris during the conveyance process. Using a video imaging and/or a gamma-ray sensor and/or other geo-radar systems like a coal-rock interface detection sensor (CID), the operator can see ahead projection of the seam-rock interface and guide the continuous miner's progress. Highwall mining can produce thousands of tons of coal in contour-strip operations with narrow benches, previously mined areas, trench mine applications, and steep-dip seams by utilizing

3456-526: The same area. However, there is evidence that life could have evolved over 4.280 billion years ago. There is a fairly solid record of bacterial life throughout the remainder (Proterozoic Eon) of the Precambrian. Complex multicellular organisms may have appeared as early as 2100 Ma. However, the interpretation of ancient fossils is problematic, and "... some definitions of multicellularity encompass everything from simple bacterial colonies to badgers." Other possible early complex multicellular organisms include

3520-574: The surface. Deposition of sediments began in the Williston area during Cambrian time, but subsidence and basin filling were most intense during the Ordovician , Silurian , and Devonian Periods, when thick accumulations of limestone and dolomite, with lesser thicknesses of sandstones, siltstones, shales, and evaporites were laid down. Subsidence continued on a reduced scale into the Mississippian and

3584-566: The waste rock of which is used to flatten out the surrounding land by infilling rivers and valleys. This is very destructive as it physically permanently alters the landscape and the associated ecosystem. Throughout the Appalachians in states such as Kentucky and Virginia, mountaintop removal is a common mining method where whole forests are cleared and the area becomes vulnerable to possible landslides, with restoration sometimes being too difficult/costly. Dredging - A form of surface mining where

3648-416: The water and decreased aquatic biodiversity . The statement also estimates that 724 miles (1,165 km) of Appalachian streams were buried by valley fills from 1985 to 2001. Blasting at a mountaintop removal mine expels dust and fly-rock into the air, which can then disturb or settle onto private property nearby. This dust may contain sulfur compounds, which some claim corrode structures and tombstones and

3712-405: The world's largest types of mine and the size of these operations leave behind massive landscape scars, destruction to environmental habitats, and substantial clean-up cost. An open-pit mine can yield an enormous quantity of waste rock, sinkholes can form down the road, flooding and similar negative impacts as strip mining. Mountaintop removal mining - Involves the removal of whole mountaintops,

3776-520: Was accomplished through manual labor, horse-drawn vehicles, and/or mining railways. Current practices tend to use haul trucks on haul roads designed into the features of the mine. Federal governments have imposed multiple laws and regulations which mining companies have to strictly follow. In the United States, the Surface Mining Control and Reclamation Act of 1977 mandates reclamation of surface coal mines. Reclamation for non-coal mines

3840-584: Was deposited during the Mississippian , followed by the Madison Group and the Big Snowy Group . The Tyler Formation was deposited in the Pennsylvanian , and consists of interbedded sandstone, siltstone , shale, and limestone . The overlying Minnelusa Formation is characterized by deposition in alluvial plains , prograding river delta , and barrier island environments. The Minnekahta Formation

3904-1123: Was deposited during the Permian , followed by the Spearfish Formation and the Nesson Formation. The Pierre Shale was deposited curing the Cretaceous , followed by the Hell Creek Formation , and the Tertiary Fort Union Formation . Several confirmed impact craters are located in Williston Basin such as Viewfield , Red Wing Creek , and Eagle Butte while the Dumas and Hartney craters are still unconfirmed. 49°N 104°W  /  49°N 104°W  / 49; -104 Precambrian The Precambrian ( / p r i ˈ k æ m b r i . ə n , - ˈ k eɪ m -/ pree- KAM -bree-ən, -⁠KAYM- ; or Pre-Cambrian , sometimes abbreviated pC , or Cryptozoic )

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3968-482: Was lacking in free oxygen . There is, however, evidence that an oxygen-rich atmosphere existed since the early Archean. At present, it is still believed that molecular oxygen was not a significant fraction of Earth's atmosphere until after photosynthetic life forms evolved and began to produce it in large quantities as a byproduct of their metabolism . This radical shift from a chemically inert to an oxidizing atmosphere caused an ecological crisis , sometimes called

4032-587: Was largely ended by Pennsylvanian time. Regional subsidence returned during the Mesozoic Era, although total sediment thicknesses were much less than during the Paleozoic . Near the end of the Cretaceous , tectonic activity during the Laramide Orogeny rejuvenated several basement structures in the Williston Basin to produce anticlines that serve as oil traps today. The long history of sedimentary deposition in

4096-846: Was mud 551 million years ago. The RNA world hypothesis asserts that RNA evolved before coded proteins and DNA genomes. During the Hadean Eon (4,567–4,031 Ma) abundant geothermal microenvironments were present that may have had the potential to support the synthesis and replication of RNA and thus possibly the evolution of a primitive life form. It was shown that porous rock systems comprising heated air-water interfaces could allow ribozyme - catalyzed RNA replication of sense and antisense strands that could be followed by strand-dissociation, thus enabling combined synthesis, release and folding of active ribozymes. This primitive RNA replicative system also may have been able to undergo template strand switching during replication ( genetic recombination ) as

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