Oct 31, 2016 what are the types of tectonic plate boundaries. Understanding plate motions this dynamic earth, usgs. Types of volcanism associated with plate margins there are two types of plate margin. Continental drift, sea floor spreading and plate tectonics.
Three types of plate boundaries exist, with a fourth, mixed type. Earthquake epicenters occur mostly along tectonic plate boundaries, and especially on the pacific ring of fire. Igneous rocks and plate tectonics book summaries, test. The western margin of south america is a tectonically active region where the. The process of drawing a picture involves students much more deeply than reading or discussion. Early evidence for plate tectonics book summaries, test. Divergent boundaries occur where two plates move apart from each other. Global distribution of earthquakes and volcanoes plate. The next time you teach plate tectonics, consider a drawwithme presentation that will engage your students and help them understand the spatial and movement aspects of plate boundary environments. One of these is that plate tectonic processes have led to the evolution of the earth. In the previous chapter we learned about the crust as the solid outer layer of earth. What are the different types of plate tectonic boundaries. Convergent plates push boundaries together transform conservative plates. Various types of quantitative and semiquantitative information are available to constrain past plate motions.
When tectonic plates move, they do not move across the earth in a line as if pushing a book across a table. The earths crust is divided into six large pieces, and about twenty smaller pieces, by deep fault systems. Aside from all the details of plate tectonic theory explored below a couple of significant concepts come from plate tectonic theory. At an average rate of 33 feet per 100 years about 10 cmyear, a tectonic plate can move 62. Plate boundary zones broad belts in which boundaries are not well defined and the effects of plate interaction are unclear. Teaching plate tectonics with easytodraw illustrations. The third group of seamounts is composed of those making up. Third, the evidence and understanding of earth that would have supported plate tectonic theory simply didnt exist until the middle of the 20th century. This video was produced by rasa juras, an undergraduate at the university. This type of plate margin occurs when the two plates are moving away from each other, i. Geology2 plate tectonics from the late latin tectonicus, from the template. The theory encompasses the older concepts of continental drift, developed.
Remember, the earths lithosphere, which includes the crust and upper mantle, is made up of a series of pieces, or tectonic plates, that move slowly over time. Where the plates meet, their relative motion determines the type of boundary. American atlantic coast active margins divergent plate boundaries. Today, plate tectonics is the unifying theory of the entire field of. Basins can be described instead in terms of the type of substratum beneath the basin, the proximity of the basin to a plate margin, and the type of plate juncture nearest to the basin. Plates rip apart at a divergent plate boundary, causing volcanic activity and shallow earthquakes. It is thinner than the continental crust generally less than 10 kilometers thick and denser. Aug 23, 2017 warmed by the blazinghot core, the mantle churns in circular convection currents, dragging tectonic plates along for the ride. Convergent plate margins is a more complex margin including blueschist facies. The mediterraneanalpine region between the eurasian and african plates is a good example of a plate boundary zone. The rise of hot mantle material beneath the rift zone pushes the rift. Sfn is a scientific theory that describes the largescale motion of earths lithosphere.
It is at these plate boundaries that most volcanic activity occurs. From wikipedia, the free encyclopedia plate tectonics from greek, tekton builder or mason describes the large scale motions of earths lithosphere. Tectonic plates and plate boundaries earthquakes at a. Heres a short description of the 3 types of plate tectonics. Plate tectonics is the theory that earths outer shell is divided into several plates that glide over the mantle, the molten rocky layer above the core. Pacific belt also called the rim of fire follows the rim of the pacific ocean and hosts over 80 percent of the worlds shallow and medium.
Currently, there are seven or eight major plates in the earth. Divergent plates pull apart from each other convergent plates. An oceanic plate is a tectonic plate at the bottom of the oceans. Metamorphism through plate tectonics linkedin slideshare. Types of plate margin v olcanoes and earthquakes mainly occur along plate boundaries where magma can escape from the earths mantle or where stresses build up between 2 plates rubbing together. Describe the three types of plate boundaries and the features of each type of boundary. Divergent plate boundarypassive continental margins. Since the development of the theory, geologists have had to reexamine almost every aspect of. Recent advances focuses on key topics or areas where the greatest strides forward have been made, while also providing on.
As ideas concerning plate tectonics have evolved since the 1970s, it has become apparent that while the theory can be applied rigorously to the oceans, the same cannot be said of the continents. Tectonic plate boundaries that do not fall neatly into one of the above tectonic boundary types are called plate boundary zones. Exactly how this works is still a matter of debate. A constructive margin can also be called a divergent margin. Plate tectonics is a scientific theory describing the largescale motion of seven large plates and the movements of a larger number of smaller plates of the earths lithosphere, since tectonic processes began on earth between 3 and 3.
Earthquakes and plate tectonics book summaries, test. According to plate tectonic theory, the lithosphere is divided into rigid plates that interact with one another at their boundaries. Plate tectonics, our major paradigm for how the earth works, was established in the 1960ies following decades of observational research that culminated in key discoveries such as geomagnetic. Tectonic plates are responsible for shaping the earths crust. According to the plate tectonic theory, the lithosphere breaks up into the tectonic plates. Pdf introduction to plate boundaries and natural hazards. The current model types of plate boundaries passive margin n. Warmed by the blazinghot core, the mantle churns in circular convection currents, dragging tectonic plates along for the ride. Sep, 2019 according to plate tectonic theory, the lithosphere is divided into rigid plates that interact with one another at their boundaries. The denser plate is subducted underneath the less dense plate.
Plate tectonics during the past 40 years, a new model has emerged and revolutionized earth sciences like perhaps no other before. The earths structure and plate tectonics plate margins and. Plate tectonics is the scientific theory of large scale plate movements of the earth. Types of plate tectonic boundaries learn with flashcards, games, and more for free. Their movement results in three kinds of plate tectonic boundaries. Jun 12, 2017 metamorphism means change in the rock texture and mineral composition of a rock. Physical geology by steven earle is licensed under a creative commons attribution 4. Plate tectonics provides a basis for understanding the distribution and origin of mineral and energy resources in space and time rona, 1977. When there is a boundary between two diverging tectonic plates, such as between the north american and eurasian plates, it is known as a constructive plate margin.
Demonstrating the movement of the earths crust and how tectonic plates interact at plate margins. Early evidence for plate tectonics magma generation, igneous intrusions, metamorphism, volcanic action, earthquakes, faulting, and folding are usually the result of plate tectonic activity. Find the top 100 most popular items in amazon books best sellers. Tectonic motion first began around three billion years ago. Plate boundaries and natural hazards, geophysical monograph series. An exception to this includes hawaii, which is found in the middle of the pacific plate over a hot spot. When the earth originated it contained no continents, and consisted of only a few kinds of igneous rock roughly the composition of the moon. The plate being forced under is eventually melted and destroyed.
The transitions from thick continental to thin oceanic crust are passive continental margins because they are far away from the current plate boundary at the midatlantic ridge. Plate tectonics simple english wikipedia, the free. This substantially revised edition includes recently published information relating to plate tectonics and continental origin. The greatest quiz on tectonic plates youll ever attempt. Distinctly different from the two other classes of. Each plate is in motion relative to its neighbours, resulting in geological activity at the plate boundaries. Identify types of plate boundaries and compare their characteristic earthquake. Types of volcanism associated with plate margins essay. The earth is composed of layers of different composition and physical properties, principally the solid central core, the fluid peripheral core, the viscous mantle, and the solid. Midocean ridges formation of oceanic plates rift valleys gulf of california, rio grande valley, red sea, east africa.
Each boundary serves a different purpose, and mountains are also the result of activity on these boundaries. Volcanoes however, only occur at constructive and destructive plate margins. Because of the strength and rigidity of oceanic plates, deformation is focused. In the theory of plate tectonics the outermost part of the earths interior is made up of two layers, the outer lithosphere and the inner asthenosphere the lithosphere essentially floats on the. More felsic magmas, such as andesites and rhyolites, are associated with the edges of continental crust at subduction zones along converging plate boundaries. It is primarily made of mafic rocks, rich in iron and magnesium. Tectonics of sedimentary basins wiley online books. Divergent plate margins show greenschist facies metamorphism and the metamorphic rock is metabasalt. Plate tectonics the tectonic plates of the world were mapped in the second half of the 20th century.
There are three types of tectonic plate boundaries. Divergent boundaries occur along spreading centers where plates are moving apart and new crust is created by magma pushing up from the mantle. Earthquakes and plate tectonics earthquakes occur in well. The earths lithosphere, which includes the crust and upper mantle, is made up of a series of pieces, or tectonic plates, that move slowly over time. In other words, as new crust forms at oceanic ridges by magma. Plate tectonics is a theory of geology developed to explain the phenomenon of continental drift, and is currently the theory accepted by the vast majority of scientists working in this area. This chapter will examine the evidence for plate tectonics and the mechanism by which it works. The geosynclinal terminology used prior to the advent of plate tectonics is inadequate to describe fully the plate tectonic settings of sedimentary basins. The following quiz tests your knowledge on plate tectonics. Jul 28, 20 the plate tectonic theory is based on the continental drift concept the theory was first developed in the first decades of 20th century.
Continental drift, sea floor spreading and plate tectonics plate tectonics is a theory developed in the late 1960s, to explain how the outer layers of the earth move and deform. The key principle of plate tectonics is that the lithosphere exists as separate and distinct tectonic plates, which ride on the. Conservative transform plate boundaries slide across from each other now, lets take a look at each type of tectonic plate boundary in a bit more detail. Voluminous igneous intrusions and frequent volcanic eruptions. The central block drops to form a graben, and basaltic volcanism is abundant along the rifts faults. Nov 06, 2019 tectonic plates are responsible for shaping the earths crust. A large number of new figures have been added, and new sections included on meteorites, seismic tomography, mantle convection, accretionary terranes, mantle sources and evolution, continental growth, secular changes in earth history, also a new chapter on exogenic.
The earths tectonic plates, which make up the earths crust, float upon the hot rocks of the mantle below. At a convergent plate boundary, one plate dives subducts beneath the other, resulting in a variety of earthquakes and a line of volcanoes on the overriding plate. The earths structure and plate tectonics plate margins. This theoretical model builds on the concept of continental drift which was developed during the first few decades of the 20th century. There are 3 types of plate boundaries, depending on how the plates move relative to each other. Four types of boundaries between tectonic plates sciencing. Illustration of the main types of plate boundaries 55 k divergent boundaries.
The geometric fit between continents, such as between west africa and south america is still an important part of plate reconstruction. The theory has caused a revolution in the way we think about the earth. Every continent formed rises above the sea due to plate tectonics. The lithosphere is divided into plates, some of which are very large and can be entire continents heat from the mantle is the source of energy driving plate tectonics. A divergent plate boundary is formed where tensional tectonic forces result in the crustal rocks being stretched and finally split apart, or rifted. The theory of plate tectonics explains most of the features of earths surface. A synopsis of plate tectonics james madison university.
Plate tectonics simple english wikipedia, the free encyclopedia. The geosynclinal terminology used prior to the advent of plate tectonics is inadequate to describe fully the platetectonic settings of sedimentary basins. Plate boundaries the movement of tectonic plates is most evident at the boundaries between the plates. Dipietro, in geology and landscape evolution second edition, 2018. In particular, plate tectonics explains geologic features on the crust over a wide scale, such as the distribution of. Plate tectonics summary the earth is made up of 3 main layers core, mantle, crust on the surface of the earth are tectonic plates that slowly move around the globe plates are made of crust and upper mantle lithosphere there are 2 types of plates there are 3 types of plate boundaries volcanoes and earthquakes are closely. The occurrence of energy and mineral deposits can be related to plate tectonics in three ways.
In plate tectonic theory, the lithosphere is broken into tectonic plates, which undergo some large scale motions. The plate tectonic revolution of the 1960s provided the framework for detailed models on the structure of orogens and basins, summarized in a 1995 textbook edited by busby and ingersoll. The continents moved away from one another as parts of different tectonic plates. This image shows the three main types of plate boundaries. Tectonic plates and plate boundaries earthquakes at a plate. An example of a subduction zone formed from a convergent boundary is the chileperu trench. In plate tectonics, a convergent boundary, also known as a destructive plate boundary because of seduction, is an actively deforming region where two or more tectonic plates or fragments of the lithosphere move toward one another and collide.
Tectonic plates move at rates that vary from less than 6 feet per 100 years to 66 feet per 100 years 1. Plate tectonics is a scientific theory describing the largescale motion of seven large plates and. Igneous rocks and plate tectonics mafic basaltic and ultramafic magmas form along the divergent midoceanic ridges and are major components of new oceanic crust. I had an introductory class in geology in college which did not address plate tectonics and i had difficulty in keeping up with the terminology in this book. It is also possible, though less common, for geological activity to take place in the middle of plates. Voluminous igneous intrusions and frequent volcanic eruptions occur at two of the major types of plate boundaries. The earth is spherical, which requires that plates rotate about a pole of rotation that emanates upward from the center of earth to intersect the earths surface. Convergent boundaries a convergent boundary is where two tectonic plates push together. It causes earthquakes, volcanoes, the rise of mountains etc. I was able to manage a rudimentary understanding of this book. Earthquakes are found along all types of plate margins as shown on this map. Convergent boundaries destructive or active margins occur where two plates.
The eastern margins of north and south america and the western margins of europe and africa are. Earthquakes, faults, and folds take place at these boundaries. The type of plate boundary and the type of crust found on each side of. The theory of plate tectonics is now wellestablished and forms the basis of our current understanding of the structure and dynamics of our earth. Earthquakes can range in size from those that are so. Plate tectonics is a model that explains the origins of continents and oceans, folded rocks and. Plate tectonics from the late latin tectonicus, from the greek. Global plate tectonic movement an earthquake also known as a quake, tremor or temblor is the shaking of the surface of the earth resulting from a sudden release of energy in the earth s lithosphere that creates seismic waves. Subduction zones occur when one or both of the tectonic plates are composed of oceanic crust. Schematic representation of the three types of plate boundaries.
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