Continental margins on the leading edges of tectonic plates, like those around the rim of. 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. Because a transform plate boundary is, by definition, a location where two plates are. Plate tectonics simple english wikipedia, the free. The movement of the plates toward or away from each other either directly or indirectly creates the major geologic features at earths surface. Passive margins are only passive in that they are not active plate boundaries. Since then better understanding and technology have refined the theory to explain how the earth has been shaped. The initiation of plate tectonics on earth is a critical event in our planets history. Plate margins are characterized by a combination of tectonic and topographic features. Find the top 100 most popular items in amazon books best sellers. The layer below the lithosphere is the asthenosphere. Plate tectonics khan academy mini lecture duration. Plate boundaries convergent, divergent, and transform.
The oceanic plate is denser than the continental plate so, as they move together, the oceanic plate is forced underneath the continental plate. Active margins are commonly the sites of tectonic activity. The earth is composed of layers of different composition and physical properties, principally the. It just took 3 billion years of plate tectonic processes to get the. Earthquakes and volcanic eruptions affect people all over the world. 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. The central block drops to form a graben, and basaltic volcanism is abundant along the rifts faults. Oct 05, 2015 a geography display that shows the different types of plate boundaries margins. Constructive where two plates oceanic or continental diverge move apart. As the oceanic plate is forced below the continental plate it melts to form magma and earthquakes are. The strikingly similar paleozoic sedimentary sequences on all southern continents and also in india are an example of evidence that supports continental drift.
Divergent plate boundarypassive continental margins geology. The movements of these plates can account for noticeable geologic events such as earthquakes, volcanic eruptions, and more subtle yet sublime events, like the building of mountains. A converging plate boundary the plate on the left subducts under the right hand plate. The difference between passive and active plate margins. The tectonic setting and tectonic history of a continental margin are probably the most important factors that control the character of a continental shelf and coast. It is normally taught to a year 11 bottom set and as a result contains basic tasks. The earths lithosphere, which includes the crust and upper mantle, is made up of a series of. For large plates, spin toroidal motion contributes a major portion of the net toroidal energy. The theory of plate tectonics is a widely accepted scientific theory that has wide application. In the theory of plate tectonics convergent plate junctures are the loci of orogeny1, marked surficially by arctrench systems2, and the margin of one plate is consumed in a trench subduction zone.
Tectonic plate boundaries that do not fall neatly into one of the above tectonic boundary types are called plate boundary zones. Earths tectonic plate boundaries are unusual because they can consist of continent and ocean crust. Plate tectonics explained in a simplified way for students to grasp the major concepts of plate motion and plate boundaries convergent, divergent and transform. The rise of hot mantle material beneath the rift zone pushes the rift. Along these boundaries, earthquakes are common and magma molten rock. Plates are composed of the crust and a part of the upper mantle, these two parts together are called the lithosphere. The lithosphere is the brittle outer layer of the solid earth. The formational process is called tectonics, and is manifested to those of us living on earth by earthquakes, volcanos, and mountain building in general. A constructive margin can also be called a divergent margin.
The high areas coastal plain and shelf are underlain by continental crust, while oceanic crust underlies low regions continental rise and. When did plate tectonics begin on earth, and what came before. From wikipedia, the free encyclopedia plate tectonics from greek, tekton builder or mason describes the large scale motions of earths lithosphere. This page explains the different types of plate margins, and gives a case study example of each one. The scientists have been busy the last decades with refining the theory. Plate tectonics describes why so many of the minerals. Typically they consist of a continental shelf, continental slope, continental rise, and abyssal plain. Continental drift, plate tectonics, and the bible the. While the lateral extent of modern plate can be easily defined by earthquake activity, its thickness is not physically defined.
Most divergent margins have oceanic crust on either side oceanic ridges, but very young ones might involve a continent. The earth surface has continuously been changing ever since it was formed, especially regarding the geomorphological and geological phenomena. Model the structural layers of the earth, investigate the data that led to the theory of plate tectonics, and discover the relationship between plate tectonics and earthquakes, volcanos, and mountains, through data analysis and handson activities. Plate tectonics, volcanism, and the structure of the earth. An example of a subduction zone formed from a convergent boundary is the chileperu trench. It is the name for the collective area that encompasses the continental shelf. Aug 05, 2009 an active margin is a tectonic plate boundary, a passive margin is a compositional transition within a tectonic plate. Plate tectonics cube display 4 types of plate margin. Write the correct number under each of the illustrations below.
A medium growth rate 5090mm per year forms a less well defined rift and a fast growing ridge 90mm per year forms a smooth crest. A read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks on a figure, or views or downloads the fulltext. Plates of lithosphere move because of convection currents in the mantle. The current model types of plate boundaries convergent plate boundaries. The theory encompasses the older concepts of continental drift, developed.
They are caused by the movement of tectonic plates. It states that earths outer shell is made up of many different plates, all which glide over top the earths mantle. Yet, apart from the frequent use of cliches such as tectonic shift by economists, journalists, and politicians, the science itself is rarely mentioned and poorly understood. This type of plate margin occurs when the two plates are moving away from each other, i. Four types of boundaries between tectonic plates sciencing. There are three major types of plate boundaries, each associated with the formation of a variety of geologic features. Modified from an introduction to grand canyon geology, by l. Continental drift, sea floor spreading and plate tectonics. Usually, one of the converging plates will move beneath the other, a process known as subduction. Constructive, destructive, conservative and collision. What are the limitations of the plate tectonic theory.
An exception to this includes hawaii, which is found in the middle of the pacific plate over a hot spot. Plate boundaries can be located by outlining earthquake epicenters. Plate margins can be places where the plates diverge, converge, or slip laterally past each other. Since the development of the theory, geologists have had to reexamine almost every aspect of. A divergent boundary occurs when two tectonic plates move away from each other. All this evidence, both from the ocean floor and from the continental margins, made it clear around 1965 that continental drift was feasible and the theory of plate tectonics, which was defined in a series of papers between 1965 and 1967, was born, with all its extraordinary explanatory and predictive power. As you probably know the theory of plate tectonics posits the outer layer of the earth consist of plates which move relative to each other driven by convection in the mantle. Plate tectonics could be essential for life astrobiology. Lecture 4 plate tectonics mechanisms and margins1 lecture. A continuous kinematic model of platetectonic motions. Plate tectonics is the process of continents on the earth drifting and colliding, rock grinding and scraping, mountain ranges being formed, and earthquakes tearing land apart. Conservative plate boundary tectonic plate margin where two. The content examines the development of the plate tectonic theory and provides information on ridges, hotspots, plate motions, and human interactions.
There are three types of tectonic plate boundaries. A divergent plate boundary is formed where tensional tectonic forces result in the crustal rocks being stretched and finally split apart, or rifted. Three types of tectonic plates boundaries and associated transform faults. Aug 31, 2010 twentyyear study yields precise model of tectonic plate movements more information. Topics covered on the quiz include the theory of plate tectonics and how to. The tectonic plates of the world were mapped in the second half of the 20th century. Transform boundaries conservative occur where two lithospheric plates slide, or perhaps more. These tectonic plates rest upon the convecting mantle, which causes them to move. Price, 1999, grand canyon association, grand canyon, arizona. Superimposed in red are the more than 400 national park system sites. When plate tectonics began shaping the earths surface has been a matter of debate, but new evidence from ancient rocks in greenland suggests a start date.
Tectonics comes from the greek word meaning builder. You can think of the tectonic setting as a first order control on the morphology of a coastal zone. Plate tectonics is the geologic theory that earths crust is made up of rigid plates that float on the surface of the planet. 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. It uses a series of animations, diagrams and word fills to further students understanding. As summarized in chapter 3, magma is formed at three main platetectonic settings. Each plate is in motion relative to its neighbours, resulting in geological activity at the plate boundaries. Tectonic processes occurring within the continental crust are also focussed on the plate boundaries and a consequence of melting within and above the subducting margins, or are due to the closure of oceans when the constructive margins are absent or overridden. With a slow growth rate 1015mm per year a deep rift valley is created under the ocean. What are the different types of plate tectonic boundaries. The story of plate tectonics this web version of a book by jacquelyne kious and robert tilling at the usgs, covers plate tectonics from a historical perspective. A passive margin is the transition between oceanic and continental lithosphere that is not an active plate margin.
Lithosphere is divided into plates that slide around on top of the slowly moving mesosphere tectonic plates it occurred after the breakup of. Plate tectonic motions affect earths rock cycle, climate, and the evolution of life. Tectonic boundary definition of tectonic boundary by the. Earths surface is divided into a few large, thick plates that move slowly and change in size plate is a large, mobile slab of rock that is part of earths surface, bounded on four sides by weak plane surfaces plate. How many different kinds of plate boundaries are there. Plate tectonics is the fundamental representation of motion and deformation of earths surface over at least the last several geological time periods wessel and muller, 2015 and we rely on. The theory of plate tectonics was advanced in the 1960s and 1970s to generate new information about the earths ancient magnetism, the nature of the ocean floor, the flow of heat from the earths interior, and earthquake and volcanic distribution with the main aim of explaining how the earth works. Plate tectonics plate tectonics evidence supporting the hypothesis. The theory of plate tectonics explains the relative movement of crustal plates that are juxtaposed with each other to form an interlocking pattern of plate boundaries, oceanic trenches, mountain ranges, etc. Tectonic plate meaning in the cambridge english dictionary. Plate tectonics examples, body, process, earth, type, form. Plate tectonics plate tectonics is a theory that has only been around for a couple of decades. The mediterraneanalpine region between the eurasian and african plates is a good example of a plate boundary zone. Dynamical instability produces transform faults at midocean ridges.
These boundary zones have plate movement deformation that occurs over a broad region, or belt. This image shows the three main types of plate boundaries. The actively accreting prism uplifted the shelf edge forming the. Collision where two continental plates converge meet. If two tectonic plates collide, they form a convergent plate boundary. Hot magma rises to the surface to produce an igneous rock known as basalt. This sketch summarizes the type of plate margins and the geological processes going on underneath your feet.
Feb 05, 2016 this lesson looks at the 4 different plate margins. Plate tectonics defines the movements and features of the earths surface now and in the past. Continental boundary a boundary between lithospheric plates where the plates move toward each other and one plate is recycled into the mantle. In a plate tectonic framework, the area spanned the continental shelf and coastal plain of an ancient passive continental margin. The lithosphere, which is the rigid outermost shell of a planet the crust and upper mantle, is broken up into tectonic plates. Tectonic plates are pieces of the rocky outer layer of the earth known as the crust. In the theory of plate tectonics, a boundary between two or more plates. The time lag between the first protosubduction about 4 billion years ago and global tectonics. The theory of plate tectonics geology lumen learning. Plate tectonics is a revolutionary theory on a par with modern genetics. Plate tectonics the environmental literacy council. Crust mantle core crust lithosphere plate movement the crust is broken into plates that move.
Earth has 7 major plate tectonic boundaries and 10 or so minor ones. The main tectonic plates boundaries and boundary types the theory of plate tectonics or continental drift was not accepted for many years largely due to there not being any credible explanation available of a driving force that would be necessary for powering the movement of land masses that were continental in scale and which could only be thought of as being of truly immense weight. Plate boundaries the different types of plate boundaries gcse geography duration. These plates are constantly moving, and volcanoes and earthquakes are found at plate boundaries. The absence of sufficient mechanism for plate motion, the uncertainty regarding the existence of seafloor spreading, and the doubts about subduction cause us to question the popular geologic syntheses known as plate tectonics. Students extend and finish the mind map example based on the information provided i. Full lesson looking at the different properties of tectonic boundaries. Because of the mountainous terrain, most of the rivers are fairly short, and the continental shelf is narrow to nonexistent, dropping off quickly into the depths of the subduction trench. Because of the low gradient and shallow depths, shelf environment are. Exactly how this works is still a matter of debate. Types of tectonic plate margins science flashcards quizlet. What features form at plate tectonic boundaries ocean.
Sizes of tectonic or lithospheric plates thoughtco. Tectonics, plate boundaries lesson teaching resources. The theory of plate tectonics is also referred to as continental drift. The point at which this happens is called the subduction zone. Plates rip apart at a divergent plate boundary, causing volcanic activity and shallow earthquakes. The theory of plate tectonics was put forward in the 1960s. Volcanoes 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. In this plate tectonic framework, large scale deformation is the local response of. Plate tectonics have changed the surface of the earth, but could they be key to life on this planet and others. Basic concepts from this simple illustrative model are then expanded to derive an analytically continuous model of presentday plate tectonic motions. The destruction of the crust takes place along plate boundaries where plates are moving toward each other, and creation of the crust occurs where plates are moving away from eachother. The concept of plate tectonics was formulated in the 1960s.
Level 3 910 marks midpoint 9 a fully developed answer, with good elaboration of a range of variations between plate margins. This diagnostic sequence consists of glacial deposits called tillites, followed by sandstones and finally coal measures, typical of warm moist climates. It coincided with a time when a large amount of research was being conducted about the ocean floors. The theory has caused a revolution in the way we think about the earth. Plate tectonics from wikipedia, the free encyclopedia plate tectonics from the late latin t e c t oni c us, from the greek. Like seams of a baseball, tectonic plate boundaries wrap around the earth. When two tectonic plates meet, we get a plate boundary. Divergent plate boundarypassive continental margins. The earths lithosphere is composed of seven or eight major plates 12 facts you should know about plate tectonics.
The largescale movements of continents across earths surface driven by the plate tectonic system. Plate tectonics the tectonic plates of the world were mapped in the second half of the 20th century. Plate tectonics evidence supporting the hypothesis. 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. Geological survey map of tectonic plates show 21 of the major plates, as well as their movements and boundaries. Learn vocabulary, terms, and more with flashcards, games, and other study tools. 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. Apr 28, 20 imho, warren hamilton, in his 2007 paper, earths first two billion yearsthe era of internally mobile crust, and, even more so, in his 2011 paper, plate tectonics began in neoproterozoic time, and plumes from deep mantle have never operated, has made a very compelling case that plate tectonics did not, and indeed could not, begin until the neoproterozoic, at the earliest. View notes lecture 4 plate tectonics mechanisms and margins1 from geo 101 at oregon state university. Plate tectonics, theory dealing with the dynamics of earths outer shell that revolutionized earth sciences by providing a uniform context for understanding mountainbuilding processes, volcanoes, and earthquakes as well as the evolution of earths surface.
There are different types of plate margins where plates interact. Also known as continental drift, the theory of plate tectonics is the reasoning behind why and how continents are constantly moving. Plate margins and collision zones plate margins and. Teach your students about plate tectonics using these classroom resources. This quiz and corresponding worksheet will help you gauge your knowledge of the types of tectonic plate boundaries. Convergent colliding boundaries are shown as a black line with teeth, divergent spreading boundaries as solid red lines, and transform sliding alongside boundaries as solid black lines. Along convergent boundaries, subduction, or one plate moving under another, carries the lower one down into the mantle. Notes on plate tectonics plate tectonics states that the earths crust and upper mantle are broken into sections, called plates. One type of motion is produced by seafloor spreading. Here is a table listing the lithospheres tectonic plates by order of size. A rounded answer with a full comparison most of features given in table above of the two main types of plate margin. Plate tectonic models for orogeny at continental margins nature. 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. In addition to the two primary types of continental margins, there also are.
262 1549 58 1344 1370 509 172 1264 1318 349 1011 1414 1293 1088 503 1036 1486 548 1514 1168 1025 819 869 1379 1351 750 1145 658 79 1125 178 511 1328 195 1397 858 848 695 73