Presentation on theme: "Minerals & Rock Unit Notes 7 th Grade Science. Rocks Are divided into 3 groups based on how they were formed Sedimentary Metamorphic Igneous Are made."— Presentation transcript:
Minerals & Rock Unit Notes 7 th Grade Science
Rocks Are divided into 3 groups based on how they were formed Sedimentary Metamorphic Igneous Are made of one or more minerals
Do not stay the same Continually changed by processes such as Weathering, Erosion Compaction, Cementation, Melting, and Cooling.
EARTH MATERIALS CHANGE BACK AND FORTH AMONG THE DIFFERENT TYPES OF ROCKS. The Rock Cycle Rocks can change to and from the 3 types
Processes that form Sedimentary Rock Weathering: the breaking down of the Earth’s material by natural processes (Water, Wind, Ice, Chemicals, etc.) into smaller pieces or sediments Erosion: weathered rock and soil particles are moved from place to place Deposition: weathered sediments are laid down in a new location creating new landforms or rocks Compaction: heavy sediments press down on the layers beneath Cementation: dissolved minerals flow between the sediments and cement them together
Melting: caused by heat and pressure around the rock to form magma Solidification: magma cools and hardens Recrystallization: while cooling, rock can develop crystals, depending on conditions Processes that form Igneous & Metamorphic Rock
Complete the following: Turn in your Rock Cycle Directed Reading & Earthquake/Volcano Test Corrections Get the 2 Directed Readings from the table Have something to write with Clear off your table
Complete the following: Turn in your Rock Cycle Directed Reading, Comic Strip & Earthquake/Volcano Test Corrections Get the Igneous Rock Directed Reading from the table Get out your Minerals & Rocks Notes Have something to write with Clear off your table
Igneous Igneous is Latin for “born of fire” Formed from cooling magma or lava
Forms when magma cools and solidifies Some reaches the surface of earth before cooling, other cools under the surface
Form below ground from magma Usually has coarse crystals (grains) from cooling slowly Some have large and small crystals Form above ground from lava Usually have small or no crystals from cooling quickly Intrusive (Example: Granite) Extrusive (Examples: Pumice & Obsidian)
intrusive extrusive Into the Bedrock On top (Exit) (crystals) (no crystals)
Complete the following: Get out your Minerals & Rocks Notes Get the Paper from the table Have a Textbook Have something to write with
But then the EARTH’S elements Will not leave the ROCK alone!
Ice Wind Water ice water wind
THEY BREAK UP THE STONE
That ROCK changed again! DEPOSIT & COMPRESS THE SEDIMENTS One way Sedimentary Rock can be formed
Sedimentary Rock Formed from sediments (rock fragments, mineral grains, animal and plant remains) that are pressed or cemented together or when sediments precipitates out of a solution. Sediments are moved by wind, water, ice, or gravity.
Water or wind breaks down (Weathering), moves (Erosion), and deposits sediment (Deposition) The heavy sediments press down on the layers beneath (Compaction) Dissolved minerals flow between the sediments and cement them together (Cementation)
Sedimentary Rocks & Fossils Deposited sedimentary rocks form horizontal layers called STRATA. Process of arranging sedimentary rocks into layers is STRATIFICATION Scientist know that the layers and fossils on top are YOUNGER than the fossils in lower layers LAW OF SUPERPOSITION
Types of Sedimentary Rocks Clastic: made of broken pieces of other rocks. Organic: remains of once living plants and animals are deposited in thick layers called fossils Chemical: minerals dissolved in lakes, seas, or underground water Limestone made when calcite precipitates from sea water Rock salt made from evaporation of sea waters
Igneous Metamorphic Sedimentary The Rock Cycle ?
Igneous Metamorphic Sedimentary The Rock Cycle squished kinda melted
Bands ( CAN ) Form Metamorphic means “changed”
Metamorphic Rocks Rocks changed due to intense heat and high pressure “Meta-” means “changed” and “-morphosis” means “shape” in Greek Igneous, Sedimentary and other Metamorphic rocks can change to become Metamorphic rocks
m How Metamorphic Rocks Change Pressure from overlying rock layers High heat, but not enough to melt the rock Rocks may be flattened or bent or atoms may be exchanged to form new materials. Think of metamorphic rocks as a squished peanut butter and jelly sandwich in your lunch.
Types of Metamorphic Rock Foliated Has visible parallel layers or bands you can see Example: Gneiss formed from rearrangement of minerals in Granite into bands Not layered & no bands are formed Example: Marble formed from Limestone Non-Foliated
Igneous metamorphic Sedimentary The Rock Cycle
The Rock Cycle
Oldest Rocks Here ! Youngest Rocks Here ! Volcano Roots here!