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Zechstein
The Zechstein (German either from ''mine stone'' or ''tough stone'') is a unit of sedimentary rock layers of Middle to Late Permian (Guadalupian to Lopingian) age located in the European Permian Basin which stretches from the east coast of England to northern Poland. The name Zechstein was formerly also used as a unit of time in the geologic timescale, but nowadays it is only used for the corresponding sedimentary deposits in Europe. The Zechstein lies on top of the Rotliegend; on top of the Zechstein is the Buntsandstein or Bunter. Formation The evaporite rocks of the Zechstein formation were laid down by the Zechstein Sea, an epicontinental or epeiric sea that existed in the Guadalupian and Lopingian epochs of the Permian period. The Zechstein Sea occupied the region of what is now the North Sea, plus lowland areas of Britain and the north European plain through Germany and Poland. The Zechstein sea lay in the rain shadow of the Central Pangean Mountains to the south. At times ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
North Sea Oil
North Sea oil is a mixture of hydrocarbons, comprising liquid petroleum and natural gas, produced from petroleum reservoirs beneath the North Sea. In the petroleum industry, the term "North Sea" often includes areas such as the Norwegian Sea and the area known as "West of Shetland", "the Atlantic Frontier" or "the Atlantic Margin" that is not geographically part of the North Sea. Brent crude is still used today as a standard benchmark for pricing oil, although the contract now refers to a blend of oils from fields in the northern North Sea. From the 1960s to 2014 it was reported that 42 billion barrels of oil equivalent (BOE) had been extracted from the North Sea since when production began, and there is still a potential of 24 billion BOE left remaining there, which is equivalent to about 35 years worth of production, the North Sea will remain as an important petroleum reservoir for years to come. History 1851–1963 Commercial extraction of oil on the shores of the North Sea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Permian
The Permian ( ) is a geologic period and stratigraphic system which spans 47 million years from the end of the Carboniferous Period million years ago (Mya), to the beginning of the Triassic Period 251.9 Mya. It is the last period of the Paleozoic Era; the following Triassic Period belongs to the Mesozoic Era. The concept of the Permian was introduced in 1841 by geologist Sir Roderick Murchison, who named it after the region of Perm in Russia. The Permian witnessed the diversification of the two groups of amniotes, the synapsids and the sauropsids ( reptiles). The world at the time was dominated by the supercontinent Pangaea, which had formed due to the collision of Euramerica and Gondwana during the Carboniferous. Pangaea was surrounded by the superocean Panthalassa. The Carboniferous rainforest collapse left behind vast regions of desert within the continental interior. Amniotes, which could better cope with these drier conditions, rose to dominance in place of their am ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Salt Diapir
A salt dome is a type of structural dome formed when salt (or other evaporite minerals) intrudes into overlying rocks in a process known as diapirism. Salt domes can have unique surface and subsurface structures, and they can be discovered using techniques such as seismic reflection. They are important in petroleum geology as they can function as petroleum traps. Formation Stratigraphically, salt basins developed periodically from the Proterozoic to the Neogene. The formation of a salt dome begins with the deposition of salt in a restricted basin. In these basins, the outflow of water exceeds inflow. More concretely, the basin loses water through evaporation, resulting in the precipitation and deposition of salt. While the rate of sedimentation of salt is significantly larger than the rate of sedimentation of clastics, it is recognized that a single evaporation event is rarely enough to produce the vast quantities of salt needed to form a layer thick enough for the formation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rotliegend
The Rotliegend, Rotliegend Group or Rotliegendes (german: the underlying red) is a lithostratigraphy, lithostratigraphic unit (a sequence of rock strata) of latest Carboniferous to Guadalupian (middle Permian) age that is found in the subsurface of large areas in western and central Europe. The Rotliegend mainly consists of sandstone layers. It is usually covered by the Zechstein and lies on top of regionally different formation (stratigraphy), formations of late Carboniferous age. The name Rotliegend has in the past not only been used to address the rock strata themselves, but also the time span in which they were formed (in which case the Rotliegend was considered a series (stratigraphy), series or subsystem of the Permian). This time span corresponds roughly with the length of the Cisuralian Epoch (reference date), epoch. Facies and formation In large parts of Pangaea, the last tectonic phase, phases of the Hercynian orogeny were still ongoing during the start of the Permian. A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Permian Basin (Europe)
The European Permian Basin is a thick sequence of sedimentary rocks deposited in a large sedimentary basin during the Permian period (from 298.9 to 251.902 million years ago) in Northern Europe. The basin underlies northern Poland, northern Germany, Denmark, the Netherlands, a significant portion of the North Sea to the east coast of England and up to Scotland. A major natural gas discovery was made in the Rotliegend Formation at Slochteren, Netherlands in 1959. The Rotliegend is the lower portion of the Permian sequence and consists of over of sandstones and evaporites. It is overlain by thick sequence of evaporites known as the Zechstein Formation.H. Zimmerle, Petroleum Sedimentology, Springer, 2008, pp. 235 - 236, See also *Permian Basin (North America) The Permian Basin is a large sedimentary basin in the southwestern part of the United States. The basin contains the Mid-continent oil field province. This sedimentary basin is located in western Texas and southeastern ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Buntsandstein
The Buntsandstein (German for ''coloured'' or ''colourful sandstone'') or Bunter sandstone is a lithostratigraphy, lithostratigraphic and allostratigraphy, allostratigraphic unit (a sequence of rock strata) in the Subsurface (geology), subsurface of large parts of west and central Europe. The Buntsandstein predominantly consists of sandstone layers of the Lower Triassic series (stratigraphy), series and is one of three characteristic Triassic units, together with the Muschelkalk and Keuper that form the Germanic Trias Supergroup (geology), Supergroup. The Buntsandstein is similar in age, sedimentary facies, facies and lithology with the Bunter (geology), Bunter of the British Isles. It is normally lying on top of the Permian Zechstein and below the Muschelkalk. In the past the name Buntsandstein was in Europe also used in a chronostratigraphy, chronostratigraphic sense, as a subdivision of the Triassic system. Among reasons to abandon this use was the discovery that its base lies a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Central Pangean Mountains
The Central Pangean Mountains were an extensive northeast–southwest trending mountain range in the central portion of the supercontinent Pangaea during the Carboniferous, Permian and Triassic periods. They were formed as a result of collision between the minor supercontinents Laurussia and Gondwana during the formation of Pangaea. At its greatest elevation during the early part of the Permian period, it was comparable to the present Himalayas. Remnants of this massive mountain range include the Appalachian Mountains and Ouachita Mountains of North America and the Little Atlas of Morocco, Africa. A number of mountain building periods were involved in the formation of the Central Pangean Mountains, including the Acadian, Caledonian, Alleghenian, Mauritanide and Variscan orogenies. The eastern portions of the range are also called the Variscan Mountains. Formation and decline The Central Pangean Mountains were formed during the collision of Laurasia and northern Gon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Group (stratigraphy)
In geology, a group is a lithostratigraphic unit consisting of a series of related formations that have been classified together to form a group. Formations are the fundamental unit of stratigraphy. Groups may sometimes be combined into supergroups. Groups are useful for showing relationships between formations, and they are also useful for small-scale mapping or for studying the stratigraphy of large regions. Geologists exploring a new area have sometimes defined groups when they believe the strata within the groups can be divided into formations during subsequent investigations of the area. It is possible for only some of the strata making up a group to be divided into formations. An example of a group is the Glen Canyon Group, which includes (in ascending order) the Wingate Sandstone, the Moenave Formation, the Kayenta Formation, and the Navajo Sandstone. Each of the formations can be distinguished from its neighbor by its lithology, but all were deposited in the same vast ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Auk Oilfield
The Auk Oilfield is situated east, southeast of Aberdeen, Scotland, in block number 30/16. Reservoir It was discovered in October 1970 in a water depth of 182 metres. The oil reservoir is a Rotliegendes sandstone overlaid with Zechstein carbonates and ls located at a depth of . Estimated ultimate recovery is of oil. The oil has an API gravity of 38 degrees and a gas-oil-ratio of 155 scf/bbl. Infrastructure The Auk 'A' platform was a steel, 8 legged jacket designed by Shell Oil and constructed at Methil, Fife, Scotland. The jacket weighs 3,414 tonnes, it was installed in July 1974 and supported a topside weight of around 8,000 tonnes. Operator It was operated by Shell UK Exploration and Production Ltd, in 50% partnership with Esso until October 2006 when it was bought by Talisman Energy, and is now licensed by Repsol Sinopec Resources UK Ltd. The field is named after the Auk a family of sea birds. Myles Bowen, Shell's Exploration Manager in 1970, had a keen i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dolomite (rock)
Dolomite (also known as dolomite rock, dolostone or dolomitic rock) is a sedimentary carbonate rock that contains a high percentage of the mineral dolomite, CaMg(CO3)2. It occurs widely, often in association with limestone and evaporites, though it is less abundant than limestone and rare in Cenozoic rock beds (beds less than about 66 million years in age). The first geologist to distinguish dolomite rock from limestone was Belsazar Hacquet in 1778. Most dolomite was formed as a magnesium replacement of limestone or of lime mud before lithification. The geological process of conversion of calcite to dolomite is known as dolomitization and any intermediate product is known as dolomitic limestone. The "dolomite problem" refers to the vast worldwide depositions of dolomite in the past geologic record in contrast to the limited amounts of dolomite formed in modern times. Recent research has revealed sulfate-reducing bacteria living in anoxic conditions precipitate dolomite which ind ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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