Definition of the theory of plate tectonics pdf

Some life rode on diverging plates, became isolated, and evolved into new species. The modern theory of the motions of earths outer layers is called plate tectonics. Plate tectonics definition of plate tectonics by the. Theories of the movement of continents were offered by a number of. Theory of plate tectonics advances in technology in the 1960s led to the development of the theory of plate tectonics which validated but improved upon wegeners earlier theory of continental drift. Lithosphere is divided into plates that slide around on top of the slowly moving mesosphere tectonic plates it occurred after the breakup of pangaea, and since then the continents. For billions of years, earth has been remodeling itself.

Following the recognition of magnetic anomalies defined by. In 1967, mckenzie and parker suggested the theory of plate tectonics. It provides a framework for understanding many of earths features, such as mountains, earthquakes, and volcanoes, as well as the distribution of fossils and the ages of rocks. Earth spins on its axis, making a full rotation roughly every 24 hours. The earth is the only planet known to currently have plate tectonics. 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.

The theory explains the presentday tectonic behavior of the earth, particularly the global distribution of mountain building. Wegener proposed that the continents plowed through crust of ocean basins, which would explain why the outlines of many coastlines like south america and africa look like they fit together like a puzzle. The fundamental concepts for geosynclinal theory were introduced in james halls presidential address for the geological society of america at the meeting of the american association for the advancement of science at montreal in 1857 knopf, 649. Geological understanding of plate tectonics durham university. Plate tectonics, theory dealing with the dynamics of earths outer shell that revolutionized earth sciences by providing a uniform context for. The drawing above is a cross section of the earth showing the. Plate tectonic theory of mountain building geography. Under the plates is a weaker layer of partially melted rock.

As plates move, the new crust gradually moves away from the ridge. The interaction of the spin and the magnetic minerals inside the earth creates earths magnetic field, stretching between the north and south. The theory, or idea, of plate tectonics says that earth s outer layer is made up of large, moving pieces called plates. We now know that, directly or indirectly, plate tectonics influences nearly. These plates are rigid segments that move in relation to one another at one of three types of plate boundaries. The theory of plate tectonics states that the earths solid outer crust, the lithosphere, is separated into plates that move over the asthenosphere, the molten upper portion of the mantle. Plate movements are responsible for most continental and ocean floor features and for the distribution of most rocks and minerals within earths crust. Plate tectonic theory had its beginnings in 1915 when alfred wegener proposed his theory of continental drift. Continental drift gained acceptance in the 1960s when the theory of plate tectonics provided a mechanism that would account for the movement of the continents. When the concept of seafloor spreading came along, scientists recognized that it was the mechanism to explain how continents could move around earths surface. Central to the theory of plate tectonics is the concept of. Fossils tell us when and where plants and animals once existed. Plate tectonic theory arose out of the hypothesis of continental drift proposed by. The term tectonics comes from a greek word meaning to build.

New oceanic crust is formed through magma rising through the gap and cooling. Earths tectonic plates collide with and dive beneath one another at convergent boundaries. Plate tectonics is the theory that the outer rigid layer of the earth the lithosphere is divided into a couple of dozen plates that move around across the earths surface relative to each other, like slabs of ice on a lake. Experiencing, listening to the extra experience, adventuring, studying, training, and more practical happenings may back you to. The theory of plate tectonics is now widely accepted. Plate tectonics is the unifying theory of the earth how did the theory develop. Plate tectonics is the theory that explains the global distribution of geological phenomena.

Plate tectonics has been one of the most successful theories in the history of the. Seafloor spreading helps explain continental drift in the theory of plate tectonics. The theory of plate tectonics chapter 14 lesson 3 p510519 a free powerpoint ppt presentation displayed as a flash slide show on id. Pdf critical analysis of the plate tectonics model and causes of. According to the theory of plate tectonics, the earths lithosphere is broken into distinct plates which are. There is no clear definition of the forces operating in plate tectonics and. Its now widely accepted that the formation of supercontinents like pangea can be explained by plate tectonicsthe scientific theory which states that earths surface is made up of a system of plates that float on top of a deeper plastic layer. As a member, youll also get unlimited access to over 79,000 lessons in math, english, science, history, and more. Evidence from fossils, glaciers, and complementary coastlines helps reveal how the plates once fit together.

Plate tectonics is a theory developed in the late 1960s, to explain how. Oceanic and continental plates come together, spread apart, and interact at boundaries all over the planet. Plate tectonics is a theory that explains the features and movement of earths surfaces currently and in. Plate tectonics is the surface manifestation of mantle convection, but the large contrast in viscosities between the lithosphere and the deeper mantle leads to departures from a simple boiling pot. Seafloor spreading theory during the 1960s, alternating magnetic properties were discovered in the rocks found on the seafloor. Plate tectonic theory is a comprehensive theory which offers explanations for various relief features and tectonic events viz. The earths crust is made up of seven main tectonic plates and numerous smaller plates. What evidence exists to support the theory of plate tectonics. Plate tectonics definition, a theory of global tectonics in which the lithosphere is divided into a number of crustal plates, each of which moves on the plastic asthenosphere more or less independently to collide with, slide under, or move past adjacent plates. Find definitions and descriptions of key plate tectonics vocabulary words and concepts used in teaching and learning about plate tectonics. Plate tectonics is the grand, unifying theory of earth sciences, combining the concepts of continental drift and seafloor spreading into one holistic theory that explains many of. Magnetism is part of the evidence for plate tectonic theory.

The mantle contains hot molten rock magma heated by energy from the earths core. In the early 1960s, the emergence of the theoryof plate tectonicsstarted a revolution in the earth sciences. Huge masses of molten rock rise from deep inside earth, cool into a solid, travel along our planets surface and then sink back down. There is sufficient proof to support it, and it is an important aspect of geology, oceanography, geophysics and even paleontology. For the rest of us, plate tectonics is a simple theory that helps make sense of the earths face. But through wegeners persistence, perseverance, and openmindedness to the contributions of others, the theory of continental drift evolved into the widely accepted theory today of plate tectonics. Plate tectonic theory definition of plate tectonic. The major mountainbuilding idea that was supported from the 19 th century and into the 20 th is the geosynclinal theory. Plate tectonics it was from the continental drift theory, convection current theory and the theory of seafloor spreading, the theory of plate tectonics was formulated. According to wikipedia, plate tectonics from the late latin tectonicus, from the greek. Plate tectonics is a theory that the earths lithosphere the crust and upper mantle is divided into a number of large, platelike sections that move as distinct masses.

Tectonic plates definition, theory, sizes of major and minor tectonic plates, convergenet, divergent and transform boundries, etc study notes. We now know that, directly or indirectly, plate tectonics influences nearly all geologic processes, past and present. The theoretical model builds on the concept of continental drift. The theory of plate tectonics grew out of earlier hypotheses and observations. Principally it refers to the movement and interaction of the earths lithosphere. The plate tectonics theory refers to the largescale movement of the seven major plates along with several other smaller plates that form the earths lithosphere, for the last hundreds of millions of years. The theory of plate tectonics geology lumen learning.

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. Continental drift, sea floor spreading and plate tectonics. Plate tectonics is the most important concept in modern geology. What does magnetism have to do with plate tectonics.

Its discovery provided a mechanism for continental drift that alfred wegener could not explain. Like the scientists before us, we will now merge the ideas of continental drift and seafloor spreading into the theory of plate tectonics. Continents are drifting across the face of our planet. This includes the formation, movement, collision and destruction of plates and the resulting geological events such as seismicity, volcanism, continental drift, and. Indeed, the notion that the entire earths surface is continually shifting has profoundly changed the way we view our world. Plate tectonics definition of plate tectonics by merriam. Tectonic plates are composed of oceanic lithosphere and. Modern continents hold clues to their distant past. Earth science students can use this as a quick reference tool. Modern uses of the word theory derive from the original definition, but have taken on new shades of meaning, still based on the idea of a theory as a thoughtful and rational explanation of the general nature of things. Tectonic theories attempt to explain why mountains, earthquakes. Seafloor spreading occurs at divergent plate boundaries which subsequently create midocean ridges. The theory of plate tectonics critique and interpret major types of evidence supporting the theory of plate tectonics.

Evidence that supports the theory of plate tectonics includes distribution of rock formation and fossils, shapes of existing continents, ocean floor features, and seismic and volcanic activity. Crust mantle core crust lithosphere plate movement the crust is broken into plates that move. Plate tectonics from the late latin tectonicus, from the greek. Geosynclinal theory the emergence and evolution of plate.