Topic: How is the Earth's crust built?

Author: Magdalena Jankun

Target group

1rd grade students of high school and technical high school (basic scope)

Core curriculum

V. Litosphere: relationship between the interior structure of the Earth and the tectonics of lithosphere plates, internal and external processes shaping the Earth's surface and their effects, rocks.

Student:

1) explains the connection between the Earth's interior structure and lithospheric plate motion and its influence on the genesis of endogenous processes;

2) explains the course of the main internal processes leading to the diversification of the Earth's surface (epicogenic movements, tectonic movements, volcanism, plutonism, earthquakes);

The general aim of education

You will describe the structure of the Earth's crust.

Criteria of success

• You will characterize the Earth's crust;

• You will name the structure of the Earth's crust.

• You will discuss the basaltic and granite zones of the Earth's crust;

• You will show the largest tectonic plates on the map of world;

Key competences

• communication in the mother tongue;

• communication in a foreign language;

• learning to learn;

• digital competence.

Methods / forms of work

• using ICT tools;

• activity with educational material and multimedia on the epodreczniki.pl platform;

• individual activity, activity in pairs, and collective activity.

Teaching aids

• e‑textbook for teaching geography;

• interactive whiteboard;

• multimedia projector;

• tablets/computers;

• physical map of world;

• map of world: tectonic plates;

• geographical atlases.

Lesson plan overview

Before classes

1. The teacher begins the lesson with the question: “What do you think - is the Earth physically changing? If yes, in what sense? Discussion.

2. Then, the teacher asks the students if they know or remember what the tectonic plate theory is. The students write their associations related to this theory on the interactive whiteboard.

3. Next, the teacher reminds students of the structure of the Earth's interior. The teacher uses an interactive exercise such as matching of elements. The teacher asks a chosen student to put the Earth's interior layers in a correct order on the interactive whiteboard.

4. In the scheme entitled „Structure of the Earth’s interior” in the abstract, the teacher indicates the outermost one - the Earth's crust. The teacher emphasizes that this is the thinnest layer of the lithosphere, which includes all of the chemical elements.

Realisation

1. The students search for information of which elements is the Earth's crust made on the Internet or in sources given by the teacher. They present the results of their work on the class forum: it is mainly made of silicon and aluminium compounds. It is formed by magma, sedimentary and metamorphic rocks.

2. The whole class analyses a table entitled „Approximate composition of the elements constructing the Earth's crust”.

3. The students get familiar with the lesson material in the abstract.

4. The teacher emphasizes that the thickness of the Earth's crust varies: from several kilometres in oceanic areas to several dozen kilometres in continental areas. Therefore, the oceanic crust and the continental crust are separated. The Earth's crust is in constant movement, both horizontally and vertically.

5. Work with geographical atlases. Using the map of world: geological structure, search for the largest tectonic plates. The selected students indicate the place of occurrence of these plates on the physical map of world. An analysis of the illustration entitled „Lithospheric „ in the abstract. The teacher comments.

6. The teacher plays a film about the theory of tectonic plates „Plate Tectonics: An Introduction” on the PBS LearningMedia webside.

7. The students work in pairs and look for the meanings of such concepts as spreading, subduction. The selected pairs will explain the terms on the class forum.

8. Joint analysis of the scheme entitled „Spreading and subduction on the boundaries of lithospheric plates”.

Summary

1. Interactive exercises to summarize the information learnt during the lesson.

2. The teacher assesses the students' activity during the lesson, appreciating their engagement and commitment.

3. Homework for the students. Using the geographical atlas, list the countries on the border of the Eurasian plate and the African plate.

The following terms and recordings will be used during this lesson

Terms

Texts and recordings

How is the Earth's crust built?

From the very beginning of its existence, geology has asked questions about how the mountains were created, why volcanoes erupt, what causes earthquakes. Not more than 100 years ago, in 1912, a revolutionary hypothesis was born known as the continental drift, now called from the surname of its creator - Wegener's theory. At the time, he was unable to explain the cause of the slow movement of continental and oceanic plates, but this concept gained more and more recognition over time. It was only when the ocean floor was studied several dozen years later that the validity of Wegener’s hypothesis was confirmed and developed into a scientific theory of tectonics of the lithospheric plates. This theory gives answers to most questions asked by modern geology. It assumes that the lithosphere zone is divided into huge plates that cover the entire planet and float on a plastic mantle. They can move apart, creating places called the spreading zones (proliferation). If two plates collide with each other, usually one of them (usually the oceanic one) slides under the other (most often the land‑based one), and the line of such a collision is called the subduction zone. The lithospheric plates can also move parallel to each other along the line of faults.

In the place where the oceanic ridge runs, there is a zone of spreading, i.e. the growth of the oceanic crust. Ocean ridge forms a network around the entire Earth. Volcanic phenomena and frequent earthquakes can be observed in this zone.