Together, these plates constitute the lithosphere, from the greek lithos, meaning rock. Since the development of the theory, geologists have had to reexamine almost every aspect of. Plate tectonics is the movement of lithospheric plates relative to each other. Plate tectonics is the theory that explains the global distribution of geological phenomena.
Scientists believe in the plate tectonics theory because of the following pieces of evidence. Modern continents hold clues to their distant past. Along spreading centers in the sea floor, melted rock rises through cracks, cools, and forms new crust that builds up midocean ridges. Tectonic theory synonyms, tectonic theory pronunciation, tectonic theory translation, english dictionary definition of tectonic theory. Continental drift timeline activity sheet continental drift. Tectonic theory definition of tectonic theory by the. An engaging video explores plate tectonics, from the evidence to support the theory to their movement.
According to the theory, earth has a rigid outer layer, known as the lithosphere, which is typically about 100 km 60 miles thick and overlies a plastic moldable, partially molten layer called the asthenosphere. Earths surface layer, 50 to 100 km 30 to 60 miles thick, is rigid and is composed of a set of large and small plates. Scientists found evidence from molten material, magnetic stripes, and drilling samples to back up wegeners theory. The lithosphere is broken up into seven very large continental and oceansized plates, six or seven mediumsized regional. Theory of continental drift proposed by alfred wegener in 1912, but not widely accepted until seafloor spreading was discovered in 1960.
Evidence for plate tectonics the evidence for plate tectonics is very conclusive. Indications of tectonic activity among the classes of evidence for continental drift and the underlying plate tectonics we may list the shapes of many continents are such that they look like they are separated pieces of a jigsaw puzzle. According to the theory of plate tectonics, the earths lithosphere is broken into distinct plates which are. He needed evidence such as fossils found on different continents, the matching shapes of the continents, rock evidence from different continents that match and the mechanism of tectonic plate movement. Plate tectonics is the theory used to explain the structure of the earths crust and many of the associated phenomenon. Students will research the evidence collected to support the theory of plate tectonics as we know it. The theory of plate tectonics grew out of earlier hypotheses and observations collected during exploration of the rocks of the ocean floor. Information includes alfred wegener plate tectonic evidence plate facts and fill in questions. 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 motion in the mantle the asthenosphere is caused by convection currents. This lesson engages students by giving them a task that requires research, critical thinking and analysis all while covering content like the theory of plate tectonics, plate boundaries and convection in the mantle optional. Some students have the misconception that after pangaea broke apart, this change became permanent. The evidence for plate tectonics is very conclusive. Problems with plate tectonics speculations science forums. 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. Sep 17, 2009 the theory of plate tectonics explains how plates and their continents move. Fossils tell us when and where plants and animals once existed.
Today, we have a much broader set of evidence in favor of the hypothesis. Plate tectonics describes the distribution and motion of the plates. This is because convection cell currents have not been proved conclusively to exist due to technological limitations we have never been able to get deep enough into earth to prove the theory. 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. It may be fantastic, but that is exactly what is happening. It has the power to explain many phenomena, such as volcanoes and earthquakes. Powerpoint click to download the ms powerpoint file 146 mbytes pdf click to view or download the presentation in pdf 5 mbytes ht ml cl ick to view the presentation in html format. Students often have the misconception that plates are evenly distributed, and thus tectonic events are evenly distributed. In 1912, wegener noticed that the coastlines of the east coast of south america and the west. In part 1, students view flash interactives and quicktime videos which delineate the relationship between volcanoes, earthquakes and plate boundaries and discuss the ancient continent of pangaea. The second discovery was the magnetic variances in the basaltic rock found on the ocean floor along the midatlantic ridge, the phenomenon is now known as. The plate tectonics revolution in the earth sciences has provided a valuable new framework for understanding longterm landform development. In its slow convergence of ideas and evidence, the history of plate tectonics holds lessons for todays.
Dec 17, 2019 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. Plate tectonic theory had its beginnings in 1915 when alfred wegener proposed his theory of continental drift. This theory is widely accepted due to the many kinds of evidence that support it. While the lateral extent of modern plate can be easily defined by earthquake activity, its thickness is not physically defined. First, the age of the crust is youngest at the plate boundaries where older rock is pushed up and the. Plate tectonics theory, formerly known as the theory of continental drift, is well supported in geology, geography and biology. Locations of earthquakes and volcanoes show the plate boundaries and ocean floor features.
Learn vocabulary, terms, and more with flashcards, games, and other study tools. Plate tectonics theory is taught in science classrooms around the world, but just 50 years ago it was a hotly contested theory. Chapter 1 plate tectonics power point linkedin slideshare. The surface of the earth is divided into a number of rigid plates that extend from the surface to the base of the lithosphere. Continental drift theory alfred wegener, 1922 plate tectonics breakup of pangea. It is a very well supported theory, and while scientific debate continues about small parts or local effects, the overall concept is accepted as good as fact. Origins of plate tectonic theory earth science visionlearning. 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. In 1967, mckenzie and parker suggested the theory of plate tectonics. This project takes about 710 days to complete and requires students to w. The theory provides a working model for analyses of phenomena that scientists observe. Some of the worksheets below are tectonic plates worksheets, predicting tectonic activity, definition of plate composition, plate movement, types of plate boundary, continentcontinent collision, handson activities, with colorful diagrams along with questions and answers at.
The theory encompasses the older concepts of continental drift, developed. Alfred wegener and continental drift it was not until 1912 that the idea of moving continents was seriously considered as a fullblown scientific theory called continental drift introduced in two articles published by a 32yearold german meteorologist named alfred lothar wegener alfred lothar wegener 18801930 earned a. Work in pairs sharing one computer with internet access. The theory of plate tectonics explains how plates and their continents move. What is some evidence for the plate tectonics theory. Practically effective listen to lou dc animation commentaries prolly shoulda known better bohmans. Plate tectonics introduction and map activity introduction to the basics of plate tectonics. On the basis of plate tectonic theory, most scientists now accept wegeners ideas about continental drift and pangea. In essence, platetectonic theory is elegantly simple. Some life rode on diverging plates, became isolated, and evolved into new species. Dec 09, 2019 some of the worksheets below are tectonic plates worksheets, predicting tectonic activity, definition of plate composition, plate movement, types of plate boundary, continentcontinent collision, handson activities, with colorful diagrams along with questions and answers at the end of each page. The theory of plate tectonics activityworksheet 1 the theory of plate tectonics worksheet objective. What are the limitations of the plate tectonic theory. Plate tectonic theory states that the earths lithosphere, or outer shell, is divided into several huge plates that glide on the slowly moving rock of earths surface.
Section 3 theory of plate tectonics key free pdf file. In plate tectonics, students are introduced to the theory behind this geophysical phenomenon and investigate the evidence that supports it. Plate tectonics and marine geology geosciences libretexts. Completed timelines can be done in any format ranging fro. Plate tectonics is the theory that explains how large pieces of the earths outermost layer, called tectonic plates, move and change shape. Third, the evidence and understanding of earth that would have supported plate tectonic theory simply didnt exist until the middle of the 20th century. The theory has caused a revolution in the way we think about the earth. What evidence did scientists find in the himalayas that support the theory of plate tectonics.
I hope this will point out a nuance that has been being passed over numerous times. It probably started to break apart from about 240 million to 200 million years ago after having been assembled from earlier continents only a few tens of millions of years earlier. The evidence against plate tectonic theory is due to the mechanics of plate movement. The theory of plate tectonics worksheet teachengineering. Evidence from fossils, glaciers, and complementary coastlines helps reveal how the plates once fit together. 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 the major structural features of the earths surface. The theory of plate tectonics geology lumen learning. There are three main pieces of evidence that support plate tectonic theory the first is the age of the earths crust showing that new rock has been formed and it still likely to be forming. Wegeners theory and sea floor maps were used to develop the theory of plate tectonics. This volume was an early classic during the controversial years before the general acceptance of plate tectonic theory. The analysis of the location of worldwide earthquakes shows scholars where major tectonic plates meet. Plate tectonics grew out of a theory that was first developed in the early 20th century by the meteorologist alfred wegener.
Section 2 the theory of plate tectonics key concept tectonic plates the size of continents and oceans move at rates of a few centimeters per year in response to filename. Remind students that because of the magma underneath the plates, tectonic plates are always moving. It is very well supported theory, and while scientific debate continues about small parts or local effects, the overall concept is accepted as good as fact. This chapter will examine the evidence for plate tectonics and the mechanism by which it works. These plates move in a number of different directions, and their movement is responsible for geological events such as mountain formation, volcanic activity, earthquakes, and. The theory of plate tectonics proposes that the lithosphere is divided into a series of plates that fit together like the pieces of a jigsaw puzzle. Dec 06, 2017 evidence for plate tectonics mounts on europa. From almost the creation of the first true maps of the earth, people started. Principally it refers to the movement and interaction of the earths lithosphere. The idea that the earths crust is made up of huge tectonic plates that are floating on an ocean of molten hot magma seemed too fantastic to be believed. 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 have drifted apart the pictures show continental drift theory from 225 million years to present. Plate tectonics the original conjectures concerning plate tectonics were based on circumstantial evidence like the shapes of continents being such that they would fit well if pushed together. From wikipedia, the free encyclopedia plate tectonics from greek, tekton builder or mason describes the large scale motions of earths lithosphere.
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. The concept of plate tectonics was formulated in the 1960s. This includes the formation, movement, collision and destruction of plates and the resulting geological events such as seismicity, volcanism. Theory of plate tectonics the theory that pieces of earths lithosphere are in constant motion on the asthenosphere. In the early 1960s, the emergence of the theoryof plate tectonicsstarted a revolution in the earth sciences. Along spreading centers in the sea floor, melted rock rises through cracks, cools, and. Plate tectonics is the unifying theory of the earth how did the theory develop. Recent seismic evidence for convection and mixing throughout the mantle seems at odds with the. Plate tectonics the tectonic plates of the world were mapped in the second half of the 20th century. Seafloor spreading was proposed as a mechanism to drive the movement of the continents on the basis of symmetrical patterns of reversed and normal magnetic rocks on the sea. Because of the strength and rigidity of oceanic plates, deformation is focused. Continental drift, sea floor spreading and plate tectonics.
The deep sea drilling project extracted samples of the ocean floor that provided evidence to support the hypothesis of seafloor spreading and the theory of plate tectonics. A plate can comprise both oceanic and continental lithosphere. List and describe the evidence for the plate tectonics theory. Gather evidence to explain the theory of plate tectonics. Although plate tectonics is a relatively young idea in comparison with unifying theories from other sciences e. The project requires that they find 15 distinct bodies of evidence for plate tectonics and find the scientists who are credited for each. Evidence that led to the development of plate tectonic theory in the 1960s came primarily from new data from the sea floor, including topography and the magnetism of rocks. A middle school lesson on plate tectonics theory for grades 68.
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