Continent formation through time
... Valley et al. 2014). These zircons provide the only direct evidence of potential crust- forming processes at this time, and the interpretation of such limited evidence is highly debated. Nebel et al. (2014) recently reviewed the evidence from the Hadean zircons (see also Roberts & Spencer 2014), and ...
... Valley et al. 2014). These zircons provide the only direct evidence of potential crust- forming processes at this time, and the interpretation of such limited evidence is highly debated. Nebel et al. (2014) recently reviewed the evidence from the Hadean zircons (see also Roberts & Spencer 2014), and ...
- NERC Open Research Archive
... correlation of sequences between the autochthonous and previously proposed allochthonous terranes; (2) isotopic evidence for similar deep crustal structure across the different terranes; (3) ocean island basalt magmas and deep marine sedimentary rocks formed during continental margin extension withi ...
... correlation of sequences between the autochthonous and previously proposed allochthonous terranes; (2) isotopic evidence for similar deep crustal structure across the different terranes; (3) ocean island basalt magmas and deep marine sedimentary rocks formed during continental margin extension withi ...
Metallogenesis of the world`s ocean against the background
... Paulo, 1981; Strakhov, 1986) provided a starting-point for the present studies. It was accepted, that recognition of the rules of forming and origin distinctness of deep-sea polymetallic deposits is of a paramount importance for the systematics of these deposits. The following key, discriminating fa ...
... Paulo, 1981; Strakhov, 1986) provided a starting-point for the present studies. It was accepted, that recognition of the rules of forming and origin distinctness of deep-sea polymetallic deposits is of a paramount importance for the systematics of these deposits. The following key, discriminating fa ...
The Palaeozoic of the Southern Alps
... originally formed the northern and western margin of Gondwana. Some of these may have been permanently or loosely attached to Africa while others including the Southern Alps split off in the early Ordovician to drift northward more or less rapidly until they successively collided and accreted with L ...
... originally formed the northern and western margin of Gondwana. Some of these may have been permanently or loosely attached to Africa while others including the Southern Alps split off in the early Ordovician to drift northward more or less rapidly until they successively collided and accreted with L ...
54. Regional Geology of the Goban Spur Continental Margin
... synthesis of the Goban Spur passive continental margin. The thin sediment sequence overlying basement is divided into three seismostratigraphic sequences. The lowest of these, sequence 3, occurs in fault-bounded basins, often wedgeshaped in cross-section. Intraformational reflector geometry shows th ...
... synthesis of the Goban Spur passive continental margin. The thin sediment sequence overlying basement is divided into three seismostratigraphic sequences. The lowest of these, sequence 3, occurs in fault-bounded basins, often wedgeshaped in cross-section. Intraformational reflector geometry shows th ...
Sedimentary Phosphate Deposits Mineral Deposit Profile F07
... Phosphatic minerals may also form the matrix. Gangue mineralogy and textures in phosphorites are determined partially by the depositional environment at the time of phosphogenesis and partially by the environment that prevailed during reworking and winnowing (natural P2O5 upgrading) of the original ...
... Phosphatic minerals may also form the matrix. Gangue mineralogy and textures in phosphorites are determined partially by the depositional environment at the time of phosphogenesis and partially by the environment that prevailed during reworking and winnowing (natural P2O5 upgrading) of the original ...
DOC, 365KB - Offshore Petroleum Exploration Acreage Release
... anticlines in the Fitzroy Trough, and a subtle unconformity in the Phoenix 1 and 2 wells; and 3. Fitzroy Movement III (Sinemurian) marking a major change in gross stratal geometries within the Roebuck Basin from predominantly backstepping to prograding and aggrading. Early Jurassic–Early Cretaceous ...
... anticlines in the Fitzroy Trough, and a subtle unconformity in the Phoenix 1 and 2 wells; and 3. Fitzroy Movement III (Sinemurian) marking a major change in gross stratal geometries within the Roebuck Basin from predominantly backstepping to prograding and aggrading. Early Jurassic–Early Cretaceous ...
Orta Anadolu`nun jeolojisi hakkında E. LAHN ÖZET: RAN 8).
... been supposed (C. E. T A Ş M A N 2 0 ) , except for the great occurence of Kayatuz Mağarası near Çankırı which shows effectively dome structures, the thickness of salt occurences is not usually sufficient for the formation of dome structures due to movements in the salt- masses« White and very gypsi ...
... been supposed (C. E. T A Ş M A N 2 0 ) , except for the great occurence of Kayatuz Mağarası near Çankırı which shows effectively dome structures, the thickness of salt occurences is not usually sufficient for the formation of dome structures due to movements in the salt- masses« White and very gypsi ...
Jurassic igneous-related metallogeny of southwestern North America
... rocks may have been widespread along the arc (reviewed by Christe and Hannah, 1990). Although Jurassic igneous systems have not received as much attention as Cretaceous and Cenozoic igneous systems, a number of representative areas are well studied. These include plutons in southern Arizona (Haxel e ...
... rocks may have been widespread along the arc (reviewed by Christe and Hannah, 1990). Although Jurassic igneous systems have not received as much attention as Cretaceous and Cenozoic igneous systems, a number of representative areas are well studied. These include plutons in southern Arizona (Haxel e ...
hofstra university 1c field guidebook a geological transect from new
... rocks. On Long Island, bedrock exposures are extremely scarce. A few examples are known near the Queens County Courthouse, and in Long Island City, at the extreme western edge of the island. In Manhattan, the Bronx, and Staten Island bedrock is exposed at the surface in scattered rocky knolls known ...
... rocks. On Long Island, bedrock exposures are extremely scarce. A few examples are known near the Queens County Courthouse, and in Long Island City, at the extreme western edge of the island. In Manhattan, the Bronx, and Staten Island bedrock is exposed at the surface in scattered rocky knolls known ...
Significant contribution of authigenic carbonate to marine carbon
... in the ocean and sediments and the aerial extent of shallow platforms was considerably larger than it is in the present. In theory, extrapolation of our global fluxes onto continental shelf environments and further reconstruction of these shelf environments in the past could yield valuable insights ...
... in the ocean and sediments and the aerial extent of shallow platforms was considerably larger than it is in the present. In theory, extrapolation of our global fluxes onto continental shelf environments and further reconstruction of these shelf environments in the past could yield valuable insights ...
M44-2003-A4-eng - Publications du gouvernement du Canada
... The oldest known rocks in the eastern Bella Coola region con sist of (?)Lower to Middle Jurassic sedimentary and volcanic rocks that correlate regionally with the youngest part of the Hazelton Group. These rocks expand the known distribution of the Early to Middle Jurassic magmatic arc sequence exp ...
... The oldest known rocks in the eastern Bella Coola region con sist of (?)Lower to Middle Jurassic sedimentary and volcanic rocks that correlate regionally with the youngest part of the Hazelton Group. These rocks expand the known distribution of the Early to Middle Jurassic magmatic arc sequence exp ...
Deep-sea basins of the Atlantic ocean
... The ocean began to form in the Central region somewhat earlier than in the Southern one. The oceanic crust began to form, in both regions, in the south , and propagated later to the north [Pushcharovskii, 1994]. The Southern and Northern oceans were connected only in the Albian, that is, 100 million ...
... The ocean began to form in the Central region somewhat earlier than in the Southern one. The oceanic crust began to form, in both regions, in the south , and propagated later to the north [Pushcharovskii, 1994]. The Southern and Northern oceans were connected only in the Albian, that is, 100 million ...
Timing and Tectonic Setting of Volcanogenic
... systems indicates that several subduction zones were active within Iapetus, making it a complex ocean akin to the modern Pacific (van Staal et al., 1998). True Iapetan oceanic lithosphere that formed at mid-oceanic spreading centres, far removed from subduction zones, has not been identified and was ...
... systems indicates that several subduction zones were active within Iapetus, making it a complex ocean akin to the modern Pacific (van Staal et al., 1998). True Iapetan oceanic lithosphere that formed at mid-oceanic spreading centres, far removed from subduction zones, has not been identified and was ...
The role of crustal and mantle sources in the genesis of granitoids of
... eruption of the Jurassic ignimbrites of Patagonia. Zircon U–Pb ages from this extensive volcanic province show that magmatism migrated away from the continental interior, where it began at c. 185 Ma, and reached the western margin of the Peninsula by 155 Ma (Pankhurst et al. 1999). In the adjacent E ...
... eruption of the Jurassic ignimbrites of Patagonia. Zircon U–Pb ages from this extensive volcanic province show that magmatism migrated away from the continental interior, where it began at c. 185 Ma, and reached the western margin of the Peninsula by 155 Ma (Pankhurst et al. 1999). In the adjacent E ...
ES Notebook Pages
... • The International Date Line is 180 o longitude (halfway around the Earth from the Prime Meridian, halfway between China and California in the middle of the Pacific Ocean). It is the highest number that can be used for longitude and it doesn’t need an East or West label. • Meridians are closer toge ...
... • The International Date Line is 180 o longitude (halfway around the Earth from the Prime Meridian, halfway between China and California in the middle of the Pacific Ocean). It is the highest number that can be used for longitude and it doesn’t need an East or West label. • Meridians are closer toge ...
Evolution of early continental crust
... cratons of North America2, West Greenland3, China4, Antarctica5 and western Australia6. This suggests that the early Archaean crust was once widespread, but now occurs as fragments, mainly within the central stable portions (cratons) of the continents. The oldest continental crust thus formed in gre ...
... cratons of North America2, West Greenland3, China4, Antarctica5 and western Australia6. This suggests that the early Archaean crust was once widespread, but now occurs as fragments, mainly within the central stable portions (cratons) of the continents. The oldest continental crust thus formed in gre ...
tectonic evolution of the japanese island arc system
... The Japanese island arcs are the best-studied example of an arc-trench system in the western Pacific (Sugimura & Uyeda 1973). The arcs consist of four segments: the western Kuril, Honshu, Ryukyu, and Izu-Bonin (Ogasawara) arcs (Figure 1c). In this review these arcs are collectively referred to as th ...
... The Japanese island arcs are the best-studied example of an arc-trench system in the western Pacific (Sugimura & Uyeda 1973). The arcs consist of four segments: the western Kuril, Honshu, Ryukyu, and Izu-Bonin (Ogasawara) arcs (Figure 1c). In this review these arcs are collectively referred to as th ...
3D restoration of a Cretaceous rift basin in Kilen, eastern North
... Upper Carboniferous–Triassic deposition took place in a fairly simple system of grabens and half-grabens referred to as the North Greenland–Svalbard Rift Basin (Håkansson & Stemmerik, 1989; Stemmerik & Håkansson, 1989, 1991). In contrast, the Jurassic– Cretaceous basin evolution is regarded as more ...
... Upper Carboniferous–Triassic deposition took place in a fairly simple system of grabens and half-grabens referred to as the North Greenland–Svalbard Rift Basin (Håkansson & Stemmerik, 1989; Stemmerik & Håkansson, 1989, 1991). In contrast, the Jurassic– Cretaceous basin evolution is regarded as more ...
Author`s personal copy
... opening of that domain. Extension in the Tyrrhenian starts in Tortonian, the oceanic spreading in the late Pliocene and Quaternary. Between the southern Tyrrhenian and Sicily outcrops a south-verging segment of the Apennine–Mahgrebrian mountain chain and thrust belt that stretches from the Alps in E ...
... opening of that domain. Extension in the Tyrrhenian starts in Tortonian, the oceanic spreading in the late Pliocene and Quaternary. Between the southern Tyrrhenian and Sicily outcrops a south-verging segment of the Apennine–Mahgrebrian mountain chain and thrust belt that stretches from the Alps in E ...
55. The Western Rockall Plateau
... Labrador Sea and spreading Greenland-Rockall away from North America (Figure 4). Spreading evidently began earlier in the southern Labrador Sea than in the north, although the rifting may have commenced as early as Early Cretaceous (Srivastava, 1978). This rifting and spreading phase was responsible ...
... Labrador Sea and spreading Greenland-Rockall away from North America (Figure 4). Spreading evidently began earlier in the southern Labrador Sea than in the north, although the rifting may have commenced as early as Early Cretaceous (Srivastava, 1978). This rifting and spreading phase was responsible ...
Tectónica e Bacias
... the unconformity between them is small to non-existent (Olsen, 1997). TS-IV includes the widespread CAMP basalts that were erupted in a geologically short interval at ~202 Ma (e.g., Olsen et al., 1996; Olsen, 1999) (The CAMP basalts comprise a large-igneous province or L.I.P.; see Section 3.1.3). Si ...
... the unconformity between them is small to non-existent (Olsen, 1997). TS-IV includes the widespread CAMP basalts that were erupted in a geologically short interval at ~202 Ma (e.g., Olsen et al., 1996; Olsen, 1999) (The CAMP basalts comprise a large-igneous province or L.I.P.; see Section 3.1.3). Si ...
Verkhoyansk Project Final Report - IIS Windows Server
... rifting in the Late Precambrian and was followed by renewed rifting/subsidence events in the Late Devonian to early Mississippian which lead to the deposition of up to 7 km of continental margin strata in the thickest part. Shortening in the fold and thrust belt began in the Latest Jurassic to Early ...
... rifting in the Late Precambrian and was followed by renewed rifting/subsidence events in the Late Devonian to early Mississippian which lead to the deposition of up to 7 km of continental margin strata in the thickest part. Shortening in the fold and thrust belt began in the Latest Jurassic to Early ...
Document
... in the Northeast of Russia is one of the most important current lines of research aimed at expansion of mineral resources of not only copper and molybdenum but also Au, Ag, and Pt-group and some other rare metals. According to the modern concept, the largest metallogenic belts in the inner zone of t ...
... in the Northeast of Russia is one of the most important current lines of research aimed at expansion of mineral resources of not only copper and molybdenum but also Au, Ag, and Pt-group and some other rare metals. According to the modern concept, the largest metallogenic belts in the inner zone of t ...
Geology 103
... - 2 common groups of iron-rich rocks: Ironstones and banded iron formations A) Banded Iron Formations (BIF) - Are mostly PreCambrian - Are huge, widespread deposits when they occur - Give evidence for oxidizing conditions in early Earth atmosphere - Are often interbedded with chert, may have limesto ...
... - 2 common groups of iron-rich rocks: Ironstones and banded iron formations A) Banded Iron Formations (BIF) - Are mostly PreCambrian - Are huge, widespread deposits when they occur - Give evidence for oxidizing conditions in early Earth atmosphere - Are often interbedded with chert, may have limesto ...
Geological history of Earth
The geological history of Earth follows the major events in Earth's past based on the geologic time scale, a system of chronological measurement based on the study of the planet's rock layers (stratigraphy). Earth formed about 4.54 billion years ago by accretion from the solar nebula, a disk-shaped mass of dust and gas left over from the formation of the Sun, which also created the rest of the Solar System.Earth was initially molten due to extreme volcanism and frequent collisions with other bodies. Eventually, the outer layer of the planet cooled to form a solid crust when water began accumulating in the atmosphere. The Moon formed soon afterwards, possibly as the result of a Mars-sized object with about 10% of the Earth's mass impacting the planet in a glancing blow. Some of this object's mass merged with the Earth, significantly altering its internal composition, and a portion was ejected into space. Some of the material survived to form an orbiting moon. Outgassing and volcanic activity produced the primordial atmosphere. Condensing water vapor, augmented by ice delivered from comets, produced the oceans.As the surface continually reshaped itself over hundreds of millions of years, continents formed and broke apart. They migrated across the surface, occasionally combining to form a supercontinent. Roughly 750 million years ago, the earliest-known supercontinent Rodinia, began to break apart. The continents later recombined to form Pannotia, 600 to 540 million years ago, then finally Pangaea, which broke apart 180 million years ago.The present pattern of ice ages began about 40 million years ago, then intensified at the end of the Pliocene. The polar regions have since undergone repeated cycles of glaciation and thaw, repeating every 40,000–100,000 years. The last glacial period of the current ice age ended about 10,000 years ago.