Plate tectonics (from the Late Latin tectonicus, from the Greek: τεκτονικός "pertaining to building")[1] is a scientific theory which describes the large scale motions of Earth's lithosphere. The theory builds on the older concepts of continental drift, developed during the first decades of the 20th century (one of the most famous advocates was Alfred Wegener), and was accepted by the majority of the geoscientific community when the concepts of seafloor spreading were developed in the late 1950s and early 1960s. The lithosphere is broken up into what are called tectonic plates. In the case of the Earth, there are currently seven to eight major (depending on how they are defined) and many minor plates. The lithospheric plates ride on the asthenosphere. These plates move in relation to one another at one of three types of plate boundaries: convergent, or collisional boundaries; divergent boundaries, also called spreading centers; and conservative transform boundaries. Earthquakes, volcanic activity, mountain-building, and oceanic trench formation occur along these plate boundaries. The lateral relative movement of the plates varies, though it is typically 0–100 mm annually
Pangaea
Pangaea, Pangæa, or Pangea (pronounced /pænˈdʒiːə/ pan-jee-ə,[1] from Ancient Greek πᾶν pan "entire", and Γαῖα Gaia "Earth", Latinized as Gæa) was the supercontinent that existed during the Paleozoic and Mesozoic eras about 250 million years ago, before the component continents were separated into their current configuration.The name was coined during a 1926 symposium discussing Alfred Wegener's theory of continental drift. In his book The Origin of Continents and Oceans (Die Entstehung der Kontinente und Ozeane) first published in 1915, he postulated that all the continents had at one time formed a single supercontinent which he called the "Urkontinent", before later breaking up and drifting to their present locations.The single enormous ocean which surrounded Pangaea was accordingly named Panthalassa
Changes in the crust:
1. Stratigraphy of the arc. Change the properties of the rock that is plastic. Can be classified into two types of rock layers bend bend the hood. The curve is a curve of the roof of the boat rocks the hood up. A curve that curves down
2. The faults are classified into three categories - normal faults. A fault with the dip of the plane of motion. The stone ceiling moves down - reverse faults. A fault with the dip of the plane of motion. The ceiling has moved up the rock - along the fault. A fault with the dip of the plane of motion through 90 degrees.
Continental slope
The continental shelf is the extended perimeter of each continent and associated coastal plain. Much of the shelf was exposed during glacial periods, but is now submerged under relatively shallow seas (known as shelf seas) and gulfs, and was similarly submerged during other interglacial periods.The continental margin, between the continental shelf and the abyssal plain, comprises a steep continental slope followed by the flatter continental rise. Sediment from the continent above cascades down the slope and accumulates as a pile of sediment at the base of the slope, called the continental rise. Extending as far as 500 km from the slope, it consists of thick sediments deposited by turbidity currents from the shelf and slope. The continental rise's gradient is intermediate between the slope and the shelf, on the order of 0.5-1°.The Karoo Ice Age from 360–260 Ma (million years ago) was the second major ice age of the Phanerozoic Eon. It is named after the glacial tills found in the Karoo region of South Africa
Mesosaurus
had a long skull that was larger than that of Stereosternum and had longer teeth. The teeth are angled outwards, especially those at the tips of the jaws. The bones of the postcranial skeleton are thick, having undergone pachyostosis. Mesosaurus is unusual among reptiles in that it possesses a cleithrum. A cleithrum is a type of dermal bone that overlies the scapula, and is usually found in more primitive bony fish and tetrapods. The head of the interclavicle of Mesosaurus is triangular, unlike those of other early reptiles, which are diamond-shaped
LystrosaurusLystrosaurus (meaning "shovel lizard", pronounced /ˌlɪstrəˈsɔrəs/) was a genus of Late Permian and Early Triassic Period dicynodont therapsids, which lived around 250 million years ago in what is now Antarctica,India , and South Africa
CynognathusCynognathus crateronotus was a metre-long predator of the Early to Middle Triassic. It was one of the more mammal-like of the "mammal-like reptiles", a member of a grouping called Eucynodontia. The genus Cynognathus had an almost worldwide distribution. Fossils have so far been recovered from South Africa, South America, China and Antarctica
LystrosaurusLystrosaurus (meaning "shovel lizard", pronounced /ˌlɪstrəˈsɔrəs/) was a genus of Late Permian and Early Triassic Period dicynodont therapsids, which lived around 250 million years ago in what is now Antarctica,
CynognathusCynognathus crateronotus was a metre-long predator of the Early to Middle Triassic. It was one of the more mammal-like of the "mammal-like reptiles", a member of a grouping called Eucynodontia. The genus Cynognathus had an almost worldwide distribution. Fossils have so far been recovered from South Africa, South America, China and Antarctica
The tectonic assembly of the continents of Euramerica (later with the Uralian orogeny, into Laurasia) and Gondwanaland into Pangaea, in the Hercynian-Alleghany Orogeny, made a major continental landmass within the Antarctic region, and the closure of the Rheic Ocean and Iapetus Ocean saw disruption of warm water currents in the Panthalassa Ocean and Paleotethys Sea, which led to progressive cooling of summers, and the snowfields accumulating in winters, causing mountainous alpine glaciers to grow, and then spread out of highland areas, making continental glaciers which spread to cover much of Gondwanaland
Glossopteris
The Glossopteridales arose in the Southern Hemisphere around the beginning of the Permian (299 million years ago). Their distribution across several, now detached, landmasses led Eduard Suess, amongst others, to propose that the southern continents were once amalgamated into a single supercontinent - Gondwana. These plants went on to become the dominant elements of the southern flora through the rest of the Permian but disappeared in almost all places at the end of the Permian (251 million years ago). The only convincing Triassic records are very earliest Triassic leaves from Nidpur , India
Oceanic ridge
continuous submarine mountain chain extending approximately 80,000 km (50,000 miles) through all the world’s oceans. Individually, ocean ridges are the largest features in ocean basins. Collectively, the oceanic ridge system is the most prominent feature on Earth’s surface after the continents and the ocean basins themselves. In the past these features were referred to as mid-ocean ridges, but, as will be seen, the largest oceanic ridge, the East Pacific Rise, is far from a mid-ocean location, and the nomenclature is thus inaccurate. Oceanic ridges are not to be confused with aseismic ridges, which have an entirely different origin. ridge
Paleomagnetism
Oceanic ridge
continuous submarine mountain chain extending approximately 80,000 km (50,000 miles) through all the world’s oceans. Individually, ocean ridges are the largest features in ocean basins. Collectively, the oceanic ridge system is the most prominent feature on Earth’s surface after the continents and the ocean basins themselves. In the past these features were referred to as mid-ocean ridges, but, as will be seen, the largest oceanic ridge, the East Pacific Rise, is far from a mid-ocean location, and the nomenclature is thus inaccurate. Oceanic ridges are not to be confused with aseismic ridges, which have an entirely different origin. ridge
Paleomagnetism
Paleomagnetism is the study of the record of the Earth's magnetic field in rocks. Certain minerals in rocks lock-in a record of the direction and intensity of the magnetic field when they form. This record provides information on the past behavior of Earth's magnetic field and the past location of tectonic plates. The record of geomagnetic reversals preserved in volcanic and sedimentary rock sequences (magnetostratigraphy) provides a time-scale that is used as a geochronologic tool. Geophysicists who specialize in paleomagnetism are called paleomagnetists.
Convection cell
A convection cell is a phenomenon of fluid dynamics that occurs in situations where there are density differences within a body of liquid or gas. The convection usually requires a gravitational field but in microgravity experiments, thermal convection has been observed without gravitational effects being needed.Fluids are materials that exhibit the property of flow. Both gases and liquids have fluid properties, and in sufficient quantity, even particulate solids such as salt, grain, and gravel show some fluid properties. When a volume of fluid is heated, it expands and becomes less dense and thus more buoyant than the surrounding fluid. The colder, denser fluid settles underneath the warmer, less dense fluid and forces it to rise. Such movement is called convection, and the moving body of liquid is referred to as a convection cell. This particular type of convection, where a horizontal layer of fluid is heated from below, is known as Rayleigh-Bénard convection.
Plate
The Earth's rocky outer crust solidified billions of years ago, soon after the Earth formed. This crust is not a solid shell; it is broken up into huge, thick plates that drift atop the soft, underlying mantle.The plates are made of rock and drift all over the globe; they move both horizontally (sideways) and vertically (up and down). Over long periods of time, the plates also change in size as their margins are added to, crushed together, or pushed back into the Earth's mantle. These plates are from 50 to 250 miles (80 to 400 km) thick
Continental plate
The current continental and oceanic plates include: the Eurasian plate, Australian-Indian plate, Philippine plate, Pacific plate, Juan de Fuca plate, Nazca plate, Cocos plate, North American plate, Caribbean plate, South American plate, African plate, Arabian plate, the Antarctic plate, and the Scotia plate. These plates consist of smaller sub-plates
Oceanic plate
The theory of plate tectonics (meaning "plate structure") was developed in the 1960's. This theory explains the movement of the Earth's plates (which has since been documented scientifically) and also explains the cause of earthquakes, volcanoes, oceanic trenches, mountain range formation, and many other geologic phenomenon
The current continental and oceanic plates include: the Eurasian plate, Australian-Indian plate, Philippine plate, Pacific plate, Juan de Fuca plate, Nazca plate, Cocos plate, North American plate, Caribbean plate, South American plate, African plate, Arabian plate, the Antarctic plate, and the Scotia plate. These plates consist of smaller sub-plates
Oceanic plate
The theory of plate tectonics (meaning "plate structure") was developed in the 1960's. This theory explains the movement of the Earth's plates (which has since been documented scientifically) and also explains the cause of earthquakes, volcanoes, oceanic trenches, mountain range formation, and many other geologic phenomenon
Divergent plates
In plate tectonics, a divergent boundary or divergent plate boundary (also known as a constructive boundary or an extensional boundary) is a linear feature that exists between two tectonic plates that are moving away from each other. Divergent boundaries within continents initially produce rifts which produce rift valleys. Most active divergent plate boundaries occur between oceanic plates and exist as mid-oceanic ridges. Divergent boundaries also form volcanic islands which occur when the plates move apart to produce gaps which molten lava rises to fill
In plate tectonics, a divergent boundary or divergent plate boundary (also known as a constructive boundary or an extensional boundary) is a linear feature that exists between two tectonic plates that are moving away from each other. Divergent boundaries within continents initially produce rifts which produce rift valleys. Most active divergent plate boundaries occur between oceanic plates and exist as mid-oceanic ridges. Divergent boundaries also form volcanic islands which occur when the plates move apart to produce gaps which molten lava rises to fill
Convergent plates
In plate tectonics, a convergent boundary, also known as a destructive plate boundary (because of subduction), is an actively deforming region where two (or more) tectonic plates or fragments of lithosphere move toward one another and collide. As a result of pressure, friction, and plate material melting in the mantle, earthquakes and volcanoes are common near convergent boundaries. When two plates move towards one another, they form either a subduction zone or a continental collision
Transform plates
A transform fault or transform boundary, also known as conservative plate boundary since these faults neither create nor destroy lithosphere. This is a type of fault whose relative motion is predominantly horizontal in either sinistral or dextral direction. Furthermore, transform faults end abruptly and are connected on both ends to other faults, ridges, or subduction zones
A transform fault or transform boundary, also known as conservative plate boundary since these faults neither create nor destroy lithosphere. This is a type of fault whose relative motion is predominantly horizontal in either sinistral or dextral direction. Furthermore, transform faults end abruptly and are connected on both ends to other faults, ridges, or subduction zones
Fold
The term fold is used in geology when one or a stack of originally flat and planar surfaces, such as sedimentary strata, are bent or curved as a result of permanent deformation. Synsedimentary folds are those due to slumping of sedimentary material before it is lithified. Folds in rocks vary in size from microscopic crinkles to mountain-sized folds. They occur singly as isolated folds and in extensive fold trains of different sizes, on a variety of scales. Folds form under varied conditions of stress, hydrostatic pressure, pore pressure, and temperature - hydrothermal gradient, as evidenced by their presence in soft sediments, the full spectrum of metamorphic rocks, and even as primary flow structures in some igneous rocks. A set of folds distributed on a regional scale constitutes a fold belt, a common feature of orogenic zones
The term fold is used in geology when one or a stack of originally flat and planar surfaces, such as sedimentary strata, are bent or curved as a result of permanent deformation. Synsedimentary folds are those due to slumping of sedimentary material before it is lithified. Folds in rocks vary in size from microscopic crinkles to mountain-sized folds. They occur singly as isolated folds and in extensive fold trains of different sizes, on a variety of scales. Folds form under varied conditions of stress, hydrostatic pressure, pore pressure, and temperature - hydrothermal gradient, as evidenced by their presence in soft sediments, the full spectrum of metamorphic rocks, and even as primary flow structures in some igneous rocks. A set of folds distributed on a regional scale constitutes a fold belt, a common feature of orogenic zones
Axial plane
The transverse plane (also called the horizontal plane, axial plane, or transaxial plane) is an imaginary plane that divides the body into superior and inferior parts. It is perpendicular to the coronal and sagittal planes.
The transverse plane (also called the horizontal plane, axial plane, or transaxial plane) is an imaginary plane that divides the body into superior and inferior parts. It is perpendicular to the coronal and sagittal planes.
Fault
In geology, a fault is a planar fracture or discontinuity in a volume of rock, across which there has been significant displacement. Large faults within the Earth's crust result from the action of tectonic forces. Energy release associated with rapid movement on active faults is the cause of most earthquakes, such as occurs on the San Andreas Fault, California.A fault line is the surface trace of a fault, the line of intersection between the fault plane and the Earth's surface
Normal fault
Normal faults generally occur in places where the lithosphere is being stretched. Consequently they are the chief structural components of many sedimentary rift basins (e.g. the North Sea) where they have major significance for hydrocarbon exploration. They can also be found in deltas, at the rear edges of huge gravitation slumps and slides. Normal faults can show diffeent geometries - and a few are shown here. In some situations the faults can become gently dipping at depth so that they have a spoon (or listric) shape. Other normal faults are found in batches, dipping in the same direction, with rotated fault blocks between. These are termed domino faults. Although most active normal faults can be shown to dip at angles steeper than 50 degrees, there are examples of very low-angle normal faults. These are often termed "detachments" - although this is a pretty vague term! Detachments show gentle dips and often expose high grade metamorphic rocks in their footwalls. These footwalls can be termed metamorphic core complexes.
In geology, a fault is a planar fracture or discontinuity in a volume of rock, across which there has been significant displacement. Large faults within the Earth's crust result from the action of tectonic forces. Energy release associated with rapid movement on active faults is the cause of most earthquakes, such as occurs on the San Andreas Fault, California.A fault line is the surface trace of a fault, the line of intersection between the fault plane and the Earth's surface
Normal fault
Normal faults generally occur in places where the lithosphere is being stretched. Consequently they are the chief structural components of many sedimentary rift basins (e.g. the North Sea) where they have major significance for hydrocarbon exploration. They can also be found in deltas, at the rear edges of huge gravitation slumps and slides. Normal faults can show diffeent geometries - and a few are shown here. In some situations the faults can become gently dipping at depth so that they have a spoon (or listric) shape. Other normal faults are found in batches, dipping in the same direction, with rotated fault blocks between. These are termed domino faults. Although most active normal faults can be shown to dip at angles steeper than 50 degrees, there are examples of very low-angle normal faults. These are often termed "detachments" - although this is a pretty vague term! Detachments show gentle dips and often expose high grade metamorphic rocks in their footwalls. These footwalls can be termed metamorphic core complexes.
Reverse faults are exactly the opposite of normal faults. If the hanging wall rises relative to the footwall, you have a reverse fault. Reverse faults occur in areas undergoing compression (squishing). If you imagine undoing the motion of a reverse fault, you will undo the compression and thus lengthen the horizontal distance between two points on either side of the fault.
Strike-slip fault
STRIKE-SLIP FAULTS Displace rock units along strike Steeply dipping faults Horizontal displacement
