Rocks and Soil

• The three main types of rocks are sedimentary, metamorphic, and igneous.
• Metamorphic rock is formed by changes to existing rocks due to heat and pressure.
• Sedimentary rock is formed from the accumulation and cementation of smaller pieces of pre-existing rocks or organisms.
• Sedimentary rock is formed from the accumulation of weathering products such as sand, mud, or shell fragments that have been compacted together over time.
• Metamorphic rock forms when existing rocks undergo changes due to heat and pressure, resulting in new minerals forming within the original rock structure.
• Sedimentary rock is made up of small pieces of other rocks that have been broken down into smaller particles called sediments.
• Weathering is the breakdown of rocks at or near Earth's surface.
• Rock layers can be used as evidence of past geological events such as volcanic eruptions, earthquakes, and floods.
• Extrusive (volcanic) igneous rock - lava quickly cools at Earth's surface
• Igneous rock can be further classified into two categories based on whether it cools above or below the Earth's surface.
• Rock cycle refers to the process whereby one type of rock can be transformed into another through weathering, erosion, deposition, and other processes.
• Rock can be classified based on its texture (grain size) and composition (mineral content).
• Igneous rock can be further classified into two categories based on how it cools and solidifies:
• Intrusive (plutonic) igneous rock - magma slowly cools underground
• The three main types of rocks are igneous, metamorphic, and sedimentary.
• Sedimentary rocks form from the accumulation of sediment deposited by water, wind, ice, or gravity.
• Sedimentary rocks are formed from sediments that have been compacted and cemented together over time.
• Metamorphism occurs when existing rocks undergo changes due to heat, pressure, and chemical reactions.
• Metamorphic rocks are formed when existing rocks undergo changes due to heat, pressure, and chemical reactions.