The physical processes on Earth create constant change. These processes—including movement in the tectonic plates in the crust, wind and water erosion, and deposition—shape features on Earth's surface.
You learned about the three rock types: igneous, sedimentary, and metamorphic. You also learned that all of these rocks can change. In fact, any rock can change to become any other type of rock. These changes usually happen very slowly. Some changes happen below Earth’s surface. Some changes happen above ground. These changes are all part of the rock cycle. The rock cycle describes each of the main types of rocks, how they form, and how they change.
The figure below shows how the three main rock types are related to each other (Figure below). The arrows within the circle show how one type of rock may change to rock of another type. These are the processes that change one rock type to another rock type.
<span>The cycle of processes by which water circulates between the earth's oceans, atmosphere, and land, involving precipitation as rain and snow, drainage in streams and rivers, and return to the atmosphere by evaporation and transpiration is called water cycle. The first picture is a picture of the water cycle.
</span>The nitrogen cycle<span> is the biogeochemical </span>cycle<span> by which </span>nitrogen is converted into various chemical forms as it circulates among the atmosphere and terrestrial and marine ecosystems. The conversion of nitrogen<span> can be carried out through both biological and physical processes.</span>