Science-Geology

TYPES OF ROCKS

  • Sedimentary Rocks: Formed by the accumulation of sediment, these rocks often contain fossils and provide clues about Earth’s history.

  • Igneous Rocks: Created from the cooling and solidification of magma, they can be classified as intrusive or extrusive based on their formation location.

  • Metamorphic Rocks: Resulting from the alteration of existing rocks through heat and pressure, these rocks can exhibit unique textures and mineral compositions

EARTH’S CRUST

  • The Earth's crust is the outermost layer of the planet, composed of a variety of rock types, including sedimentary, igneous, and metamorphic rocks, each contributing to the dynamic processes that shape the landscape.

  • The 4 layers of the earth are:

    • Crust: The layer that is the outermost part of the Earth, where we live, and is relatively thin compared to the other layers. It is made up of primarily made of a solid rock. The crust tends to be lighter than the materials below. Earth’s crust “floats” on the inner layers.

    • Mantle: The layer located beneath the crust. It is made up of a hot, thick, solid layer of partly melted rock.

    • Outer Core: The layer that is in between the mantle and the inner core. It is made up of dense, hot, region made of mostly liquid iron and nickel

    • Inner Core: The innermost layer of the Earth, composed primarily of iron and nickel, and is solid due to immense pressure despite the high temperatures.

VOCABULARY

  • Deposition-The layering down of sediments

  • Erosion-The movement of weathered rock materials from one place to another

  • Ice Wedging-When water gets between and in the cracks of the rocks and freezes so that it widens the rocks

  • Valley-Any low region of land between hills OR mountains

  • Plains-A flat area

  • Delta-Sediment builds up causing the river to fan out over a broad area

  • Fiords-A long narrow inlet of the sea

  • Weathering-When a mineral is slowly but naturally worn down

  • Mechanical Weathering-Weathering that is caused by a physical force

  • Chemical Weathering-Weathering that occurs when there is a chemical reaction between air, water, or another substance in the materials in the minerals

  • Biological Weathering-When something is growing in between the rocks so it wedges the rocks apart

The difference between magma and lava is that magma is inside of the volcano and lava is when magma spews out of the volcano.

Factors that cause the erosion of weathered rock materials are:

  • ice

  • water

  • gravity

  • wind

Weathering and erosion are different because erosion is the movement of weathered minerals

Rock cycle:

Metamorphic melts and cools into an igneous rock, then the igneous rock is eroded into sediments and the sediments layer and compact together to make a sedimentary rock, then the rock is heated and turns into a metamorphic rock and the process starts again.

8 Properties of classifying rocks:

  • color

  • streak

  • luster

  • texture

  • cleavage

  • crystal structure

  • reaction to certain chemicals

  • hardness