- Slides: 17
Rocks and the Rock Cycle
n n Rock- is a solid mixture of crystals of one or more minerals. Every mineral- has a unique set of physical properties, which can include color, hardness and the way the mineral breaks.
n Rocks are classified by 3 main types (based on how they form) igneous rock n sedimentary rock n Metamorphic rock n
n Igneous rock- forms when hot, liquid rock or magma cools and hardens. This type forms deep inside the Earth or at sites of volcanic activity.
n Sedimentary rock- forms when rocks are broken down into smaller pieces that harden into new rock. *forms on the earths surface
• In the process of erosion, rivers move sediment from one place to another Rivers Transport Sediment
• Finally, the sediment is deposited in layers Sedimentary Rock Layers After compaction and cementation sedimentary rock is formed
n Metamorphic rock- forms when rock is heated and squeezed.
n The Rock Cycle- is the continual process by which new rock forms from old rock material. Through the rock cycle, each type of rock can become any other type of rock.
The Rock Cycle (draw cycle in your notebook)
Processes that Shape the Earth March 20, 2012
n Weathering- the process of water, ice, wind and heat breaking down rocks. This is important because weathering breaks rocks into smaller pieces. These pieces make up sediments that form sedimentary rocks.
n Erosion- process where grains of rock are removed from their source. Erosion moves the sediment to a place where the sediments can collect.
n Deposition- the process in which water, ice, wind and gravity drop newly formed sediments.
Compaction: happens when sediments are deeply buried, placing them under pressure because of the weight of overlying layers. This squashes the grains together more tightly. Cementation - loose sediments are glued together by natural glues like calcite and silica. Some glues are stronger than others
n Heat and Pressure- If the temperature and pressure are high enough at the bottom of the stack, the rock can change into metamorphic rock.
n Uplift- is the process by which regions of the Earth’s crust rise to higher elevations.