Small fragments of rocks are called sediments. These sediments are transported and deposited by wind, water, etc. These loose sediments are compressed and hardened to form sedimentary rocks. For example, sandstone is made from grains of sand.

Minerals are naturally occurring substances which have certain physical properties and definite chemical composition.

Different minerals are formed under different pressure and temperature conditions. Igneous or magmatic minerals are formed due to crystallization or cooling down of lava and magma. Metamorphic minerals are those which are formed when some other mineral changes its composition when subjected to heat and pressure.

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Exogenic forces are the forces that work on the surface of the earth while endogenic forces are those forces that act in the interior of the earth.

Endogenic movements: The energy emanating from within the earth is the main force behind endogenic geomorphic processes. The earth movements are mainly of two types: diastrophism and sudden movements. Diastrophism: All processes that move, elevate or build up portions of the earth’s crust come under diastrophism.

Exogenic processes include geological phenomena and processes that originate externally to the Earth’s surface. They are genetically related to the atmosphere, hydrosphere and biosphere, and therefore to processes of weathering, erosion, transportation, deposition, denudation etc.

The principal energy sources for endogenic processes are heat and the redistribution of material in the earth’s interior according to density (gravitational differentiation). The earth’s deep heat originates chiefly from radiation.

Endogenic (or endogenetic) factors are agents supplying energy for actions that are located within the earth. Endogenic factors have origins located well below the earth’s surface. The term is applied, for example, to volcanic origins of landforms, but it is also applied to the original chemical precipitates.

Endogenic cycles, of which the phosphorus cycle is an example, are those that occur below or directly on the surface of the geosphere without a significant atmospheric component; most biogeochemical cycles are exogenic cycles in which the atmosphere serves as a conduit and often as a reservoir.

Processes caused by forces from within the Earth are endogenous processes. Exo is a prefix meaning “out”, and endo is a prefix meaning “in”. Many exogenous (extraterrestrial) forces are caused by other bodies in the Solar System. For example, the Moon causes tides in the Earth’s oceans and other big bodies of water.

Endogenic processes in geology are a function of a body’s internal geodynamic activity. The study of endogenic processes and their resulting landforms and landscapes puts important constraints on the internal evolution and the surface history of a geologic body.

Geological processes form rock over millions of years. Rocks can break into sediment and become pressed and glued together to form sedimentary rock. Sedimentary rock can change into metamorphic by added head and pressure from subduction of plates.

Among them are:

• Earthquakes.
• Eruptions of Volcanoes.
• Tsunamis.
• Landslides.
• Subsidence.
• Floods.
• Droughts.
• Hurricanes.