heres some stuff that might be usefull but you have to decide how to write it up. and dont forget to credit the posters here, this web site and the reference sites.
According to the theory of plate tectonics, the crust is divided into a number of large and small plates that float on and travel independently of the mantle. Plate motions are responsible for continental drift and seafloor spreading and for most volcanic and seismic activity on Earth.
Some geological processes, such as those that make mountains or wear them down, typically take place at imperceptible rates. Sudden events, however, can change the landscape in a minute (for example a single earthquake can create a 3-meter-high fault scarp, alter stream courses, and drop the valley floor 1 meter).
The surface of Earth is constantly changing, as the continents slowly drift about on the turbulent foundation of partially molten rock beneath them. Collisions between landmasses build mountains; erosion wears them down. Slow changes in the climate cause equally slow changes in the vegetation and animals inhabiting a place.
Read more: Earth - Physical Parameters Of Earth, The Formation Of Earth, Beyond The Atmosphere, Life - Earth's surface, Earth's atmosphere and weather
The lands of our planet are in a constant, though slow, state of change. Landmasses move, collide, and break apart according to a process called plate tectonics. The lithosphere is not one huge shell of rock; it is composed of several large pieces called plates. These pieces are constantly in motion, because Earth's interior is dynamic, with its core still molten and with large-scale convective currents in the upper mantle. The giant furnace beneath all of us moves our land no more than a few centimeters a year, but this is enough to have profound consequences.
Where a crustal plate rides over another one, burying and melting it in the hot regions below the lithosphere, volcanoes rise, dramatically illustrated by Mt. St. Helens in Washington and the other sleeping giants that loom near Seattle and Portland. Where lands lie wide and arid, they are sculpted into long, scalloped cliffs, as one sees in the deserts of New Mexico, Arizona, and Utah. Without ever being aware of it, we humans spend our lives on the ultimate roller coaster.
Look up the meaning of the the words Mantle, lithosphere, crust and include definitions for these words in your assigment.
perhaps you could include a cutaway pic of the earth showing the variouse layers of the earth.