geomorphological processes

rocks

there are three types of rock igneous metamorphic sedimentary rocks

igneous rock

igneous rocks are formed from molten rocks

the two types of igneous rocks

the molten rock which erupts onto the Earth's surface is called lava. lava cools to form rocks with smaller crystals example basalt

another type of igneous rock

the molten rock found under the Earth's surface is called magma. magma cools slowly to form rocks with larger crystals. example granite

metamorphic rocks

formed from other rocks as a result of volcanic action

volcanic activity

rocks which come into contact with magma are heated and changed to new rocks

extreme pressure

extreme pressure caused by tectonic movements can also alter rocks. example clay becomes slate

weathering

the natural breakdown of rocks at the Earth's surface

physical weathering

physical weathering happens when the weather breaks down rocks without altering them chemically

two key types

freeze thaw weathring and onion skin weathering

freeze thaw weathering

water seeps into cracks. temperature drops down below 0 degrees Celsius. water freezes and becomes ice. ice expands and creates pressure. pressure widens the crack.

onion skin weathering

the high temperature heats the rock. surface of the rock expands. temperature drops down at night. rock contracts. the surface of the rock peels.

chemical weathering

it involves chemical reactions between rain water and rocks.

biological weathering

biological weathering is the breakdown of rocks by plants animals and insects

biological weathering by plants

roots from trees and plants grow into the crack. the root widens the crack and breaks it

biological weathering by animals and insects

creatures that live underground helps to break up softer rocks just as clay

erosion

wearing away the land by wind, river, ice, sea

process of erosion

attrition, abartion, hydraulic action, plucking