Lecture 18
... through time to 2.5, the timeintegrated ratio should be somewhere in between these two v a l ues. Indeed, it is. However, the time-integrated value of 3.75 is surprisingly close to the initial value. This would imply in a simple evolutionary model of the mantle that the depletion in T h relative to ...
... through time to 2.5, the timeintegrated ratio should be somewhere in between these two v a l ues. Indeed, it is. However, the time-integrated value of 3.75 is surprisingly close to the initial value. This would imply in a simple evolutionary model of the mantle that the depletion in T h relative to ...
The fate of fluids released from subducting slab in
... are carried into the mantle by subducting slabs (e.g. Peacock, 1990). The expelled fluids are inferred to rise, hydrate, and serpentinize the forearc mantle peridotite. However, we recognize that low velocities in the mantle wedge can also be attributed to (1) presence of chlorite with antigorite, ( ...
... are carried into the mantle by subducting slabs (e.g. Peacock, 1990). The expelled fluids are inferred to rise, hydrate, and serpentinize the forearc mantle peridotite. However, we recognize that low velocities in the mantle wedge can also be attributed to (1) presence of chlorite with antigorite, ( ...
Lecture 19: Mantle Plumes - Earth and Atmospheric Sciences
... phase, is preferentially removed during melting. Thus both the crustal and mantle parts of the continental lithosphere have relatively low density, which may help to explain its stability. If the subcontinental lithosphere is residual material from which melts have been extracted, why are xenoliths ...
... phase, is preferentially removed during melting. Thus both the crustal and mantle parts of the continental lithosphere have relatively low density, which may help to explain its stability. If the subcontinental lithosphere is residual material from which melts have been extracted, why are xenoliths ...
modern accretionary processes The Palaeoproterozoic Trans
... Taken at face value, these geochronological constraints suggest that the Manikewan Ocean had formed over a time span of at least 150 Ma before it started to close, which is comparable in duration to most modern oceans. The c. 1.83– 1.80 Ga terminal collision with the Superior Province, which histori ...
... Taken at face value, these geochronological constraints suggest that the Manikewan Ocean had formed over a time span of at least 150 Ma before it started to close, which is comparable in duration to most modern oceans. The c. 1.83– 1.80 Ga terminal collision with the Superior Province, which histori ...
north american diamond deposits
... How much are diamonds worth? Many diamonds have such a high value that a person could easily carry a king’s ransom in diamonds in a shirt pocket. People tend to think of gold as a very high-value commodity, but it would require an armored truck to carry enough gold of similar value to a handful of g ...
... How much are diamonds worth? Many diamonds have such a high value that a person could easily carry a king’s ransom in diamonds in a shirt pocket. People tend to think of gold as a very high-value commodity, but it would require an armored truck to carry enough gold of similar value to a handful of g ...
Reconciling the geological history of western Turkey with plate
... Anatolide–Tauride block (ATB), rifting away from Gondwana (Africa) in the Permian (Torsvik and Cocks, 2009) or Triassic (Şengör et al., 1984), underwent Paleocene (Kaymakcı et al., 2009) or Eocene (Şengör and Yılmaz, 1981) collision with the Sakarya continental block that belonged to Eurasia since t ...
... Anatolide–Tauride block (ATB), rifting away from Gondwana (Africa) in the Permian (Torsvik and Cocks, 2009) or Triassic (Şengör et al., 1984), underwent Paleocene (Kaymakcı et al., 2009) or Eocene (Şengör and Yılmaz, 1981) collision with the Sakarya continental block that belonged to Eurasia since t ...
The westward drift of the lithosphere
... theoretical basis of these tidal drag mechanisms, and the model was abandoned. The notion that Earth’s rotation influences plate tectonics has been generally discounted due to the requirement of the conservation of the angular momentum of the Earth-Moon system, which is considered as an isolated sys ...
... theoretical basis of these tidal drag mechanisms, and the model was abandoned. The notion that Earth’s rotation influences plate tectonics has been generally discounted due to the requirement of the conservation of the angular momentum of the Earth-Moon system, which is considered as an isolated sys ...
1.6 General age and tectonic setting of the Arabian Shield
... The geologic history of the Arabian Shield covers a broad sweep of geologic time from distant beginnings more than 2,000 million years ago to present day processes that are sculpting and changing the rocks and landscape of the shield. The core of the history covers a 300-million-year period between ...
... The geologic history of the Arabian Shield covers a broad sweep of geologic time from distant beginnings more than 2,000 million years ago to present day processes that are sculpting and changing the rocks and landscape of the shield. The core of the history covers a 300-million-year period between ...
The Geology of Antarctica
... 2.1. Archaean Terrains/ Domains with Limited or Negligible Later Overprints 2.1.1 The Grunehogna Craton, Dronning Maud Land 2.1.2. The Archaean Napier Complex, Enderby Land 2.1.3. The Archaean Vestfold Block, Prydz Bay 2.1.4. Archaean in the Denman Glacier / Obruchev Hills Area 2.1.5. The Archaean t ...
... 2.1. Archaean Terrains/ Domains with Limited or Negligible Later Overprints 2.1.1 The Grunehogna Craton, Dronning Maud Land 2.1.2. The Archaean Napier Complex, Enderby Land 2.1.3. The Archaean Vestfold Block, Prydz Bay 2.1.4. Archaean in the Denman Glacier / Obruchev Hills Area 2.1.5. The Archaean t ...
True Polar Wander: Linking Deep and Shallow
... plate-tectonic componenr of APW (Figure 1). J\\ost powerfully, TPW must be recognized in the paleomagnetic record as an APvV component common to all plates in the celestial or geomagnetic reference II·ames. Plate-tectonic motion is expected to vary considerably, and even possibly sum to zero (no net ...
... plate-tectonic componenr of APW (Figure 1). J\\ost powerfully, TPW must be recognized in the paleomagnetic record as an APvV component common to all plates in the celestial or geomagnetic reference II·ames. Plate-tectonic motion is expected to vary considerably, and even possibly sum to zero (no net ...
PNAS-2014-Anderson-1..
... and most volatile material in the crust and exosphere. Core formation occurred early (9, 15), producing heat that dissipated over time. Radioactive elements were concentrated in the crust and uppermost mantle (7, 13) at that time. The entire planet cooled substantially from its initial state and is ...
... and most volatile material in the crust and exosphere. Core formation occurred early (9, 15), producing heat that dissipated over time. Radioactive elements were concentrated in the crust and uppermost mantle (7, 13) at that time. The entire planet cooled substantially from its initial state and is ...
Subcontinental Lithosphere
... than the original material. This residue is less dense is because garnet, a very dense phase, is preferentially removed during melting. Thus both the crustal and mantle parts of the continental lithosphere have relatively low density, which may help to explain its stability. If the subcontinental li ...
... than the original material. This residue is less dense is because garnet, a very dense phase, is preferentially removed during melting. Thus both the crustal and mantle parts of the continental lithosphere have relatively low density, which may help to explain its stability. If the subcontinental li ...
Three distinct types of hotspots in the Earth`s mantle
... raises the well-known di⁄culty of establishing a reliable kinematic connection between the two hemispheres through Antarctica. This has most recently been addressed by Raymond et al. [17], who discuss the importance of an extinct plate boundary within the Adare trough in Antarctica. Based on updated ...
... raises the well-known di⁄culty of establishing a reliable kinematic connection between the two hemispheres through Antarctica. This has most recently been addressed by Raymond et al. [17], who discuss the importance of an extinct plate boundary within the Adare trough in Antarctica. Based on updated ...
A-Level Handbook V4 - Earth Science Teachers` Association
... 1.1.1 An overview of planetary geology and ideas for the origin of the solar system (a) Describe the overall structure of the solar system including gas giants and terrestrial planets with a dense inner core, and current theories of its origin and age. ...
... 1.1.1 An overview of planetary geology and ideas for the origin of the solar system (a) Describe the overall structure of the solar system including gas giants and terrestrial planets with a dense inner core, and current theories of its origin and age. ...
UNIT AS GL2a OR GL2b - Earth Science Teachers` Association
... 1.1.1 An overview of planetary geology and ideas for the origin of the solar system (a) Describe the overall structure of the solar system including gas giants and terrestrial planets with a dense inner core, and current theories of its origin and age. ...
... 1.1.1 An overview of planetary geology and ideas for the origin of the solar system (a) Describe the overall structure of the solar system including gas giants and terrestrial planets with a dense inner core, and current theories of its origin and age. ...
The Westward Drift of the Lithosphere: A rotational drag?
... content of asthenospheric rocks can significantly influence their viscosity (Hirth and Kohlstedt, 1996; Mei et al., 2002). In deformation experiments on partially molten olivine aggregates, Hirth and Kohlstedt (1995a; 1995b) found that the viscosity of the upper mantle can be reduced by more than on ...
... content of asthenospheric rocks can significantly influence their viscosity (Hirth and Kohlstedt, 1996; Mei et al., 2002). In deformation experiments on partially molten olivine aggregates, Hirth and Kohlstedt (1995a; 1995b) found that the viscosity of the upper mantle can be reduced by more than on ...
SCIENCE CHINA Magmatism during continental collision
... 2010), with a 12–15 Myr gap from the initial collision. Some researchers suggested that the uplift of the Himalaya Orogen began at 50 Ma (An et al., 2001), which is contemporaneous with the UHP metamorphism. Up to now, the India plate is still moving northward at a speed of 3–4 cm yr−1. Therefore, f ...
... 2010), with a 12–15 Myr gap from the initial collision. Some researchers suggested that the uplift of the Himalaya Orogen began at 50 Ma (An et al., 2001), which is contemporaneous with the UHP metamorphism. Up to now, the India plate is still moving northward at a speed of 3–4 cm yr−1. Therefore, f ...
On the origin and tectonic significance of the intra-plate
... 2.1. The orogenic belts of Grenvillian-type age at the SW active margin In a large region at the southwestern part of the Amazonian Craton, rocks belonging to the Rondonian-San Ignacio and Sunsas orogenic provinces are exposed. Their tectonic development occurred at the end of the Mesoproterozoic, r ...
... 2.1. The orogenic belts of Grenvillian-type age at the SW active margin In a large region at the southwestern part of the Amazonian Craton, rocks belonging to the Rondonian-San Ignacio and Sunsas orogenic provinces are exposed. Their tectonic development occurred at the end of the Mesoproterozoic, r ...
Petrogenesis of felsic igneous rocks associated with the
... complex, the Nuorunen granite, and the Sumian volcanic rocks is found. U–Pb age determinations indicate that the main magmatic evolution of the Archean complex in Koillismaa took place at 2800–2700 Ma, whereafter the area was cratonized before the early Paleoproterozoic rifting began. The Koillismaa ...
... complex, the Nuorunen granite, and the Sumian volcanic rocks is found. U–Pb age determinations indicate that the main magmatic evolution of the Archean complex in Koillismaa took place at 2800–2700 Ma, whereafter the area was cratonized before the early Paleoproterozoic rifting began. The Koillismaa ...
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... The Neoproterozoic Era (Fig. 1) is when Earth and life on it began to appear modern. This was when the first complex animals developed, ice ages became common, and the atmosphere became rich with oxygen. The great Pacific Ocean basin formed, alongside the Atlantic Ocean's ancestor Iapetus. Some of t ...
... The Neoproterozoic Era (Fig. 1) is when Earth and life on it began to appear modern. This was when the first complex animals developed, ice ages became common, and the atmosphere became rich with oxygen. The great Pacific Ocean basin formed, alongside the Atlantic Ocean's ancestor Iapetus. Some of t ...
Cenozoic Formations from Erbil to Kore
... front of rising mountain chains. The molasse is deposited in a foreland basin)It is largely made up of coarse and thick fluviatile and estuarine conglomerates, products of erosion of the rising mountain--ranges-, deposited –mane or more sinking through in front of those rangesThe formation is compos ...
... front of rising mountain chains. The molasse is deposited in a foreland basin)It is largely made up of coarse and thick fluviatile and estuarine conglomerates, products of erosion of the rising mountain--ranges-, deposited –mane or more sinking through in front of those rangesThe formation is compos ...
Generation of new continental crust by sublithospheric silicic
... this paper, which is focused to test Taylor's andesite model, an outline of the most debated topic in relation to the generation of the rocks forming the continental crust is given in the next section with the aim of offering a reference framework on the problem of continental crust generation. 2. T ...
... this paper, which is focused to test Taylor's andesite model, an outline of the most debated topic in relation to the generation of the rocks forming the continental crust is given in the next section with the aim of offering a reference framework on the problem of continental crust generation. 2. T ...
Chapter 20: Anorthosites
... Highly felsic nature and their location in continental areas they share with granitoid rocks The felsic mineral, however, is a calcic plagioclase, which, along with associated high-temperature mafic minerals, suggests a stronger similarity to basaltic rocks ...
... Highly felsic nature and their location in continental areas they share with granitoid rocks The felsic mineral, however, is a calcic plagioclase, which, along with associated high-temperature mafic minerals, suggests a stronger similarity to basaltic rocks ...
Geology of granite - Royal Society of Western Australia
... The genesis of granite is intimately related to the dynamic structure of the Earth. Granite is the main component of continents; it is one of the oldest known rocks; and the geological history of granite provides the main evidence about the growth and evolution of continents through time. Granite fo ...
... The genesis of granite is intimately related to the dynamic structure of the Earth. Granite is the main component of continents; it is one of the oldest known rocks; and the geological history of granite provides the main evidence about the growth and evolution of continents through time. Granite fo ...
univERsity oF copEnhAGEn
... the cratonic keel down to depths of at least 220 –250 km was formed during a relatively short time interval by a fast tectono-magmatic event, rather than by gradual addition of new lithospheric material to the lithospheric base over a long period of time. Moreover, isotopic ages indicate that the ma ...
... the cratonic keel down to depths of at least 220 –250 km was formed during a relatively short time interval by a fast tectono-magmatic event, rather than by gradual addition of new lithospheric material to the lithospheric base over a long period of time. Moreover, isotopic ages indicate that the ma ...
History of Earth
The history of Earth concerns the development of the planet Earth from its formation to the present day. Nearly all branches of natural science have contributed to the understanding of the main events of the Earth's past. The age of Earth is approximately one-third of the age of the universe. An immense amount of biological and geological change has occurred in that time span.Earth formed around 4.54 billion years ago by accretion from the solar nebula. Volcanic outgassing probably created the primordial atmosphere, but it contained almost no oxygen and would have been toxic to humans and most modern life. Much of the Earth was molten because of frequent collisions with other bodies which led to extreme volcanism. One very large collision is thought to have been responsible for tilting the Earth at an angle and forming the Moon. Over time, the planet cooled and formed a solid crust, allowing liquid water to exist on the surface.The first life forms appeared between 3.8 and 3.5 billion years ago. The earliest evidences for life on Earth are graphite found to be biogenic in 3.7-billion-year-old metasedimentary rocks discovered in Western Greenland and microbial mat fossils found in 3.48-billion-year-old sandstone discovered in Western Australia. Photosynthetic life appeared around 2 billion years ago, enriching the atmosphere with oxygen. Life remained mostly small and microscopic until about 580 million years ago, when complex multicellular life arose. During the Cambrian period it experienced a rapid diversification into most major phyla. More than 99 percent of all species, amounting to over five billion species, that ever lived on Earth are estimated to be extinct. Estimates on the number of Earth's current species range from 10 million to 14 million, of which about 1.2 million have been documented and over 86 percent have not yet been described.Geological change has been constantly occurring on Earth since the time of its formation and biological change since the first appearance of life. Species continuously evolve, taking on new forms, splitting into daughter species, or going extinct in response to an ever-changing planet. The process of plate tectonics has played a major role in the shaping of Earth's oceans and continents, as well as the life they harbor. The biosphere, in turn, has had a significant effect on the atmosphere and other abiotic conditions on the planet, such as the formation of the ozone layer, the proliferation of oxygen, and the creation of soil.