1 / 22

Rocks!!!

Rocks!!!. Ch. 3. What is a rock?. Any solid mass of mineral or mineral-like matter that occurs naturally as part of our planet 3 types Igneous Sedimentary Metamorphic. The rock cycle.

naiya
Télécharger la présentation

Rocks!!!

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Rocks!!! Ch. 3

  2. What is a rock? • Any solid mass of mineral or mineral-like matter that occurs naturally as part of our planet • 3 types • Igneous • Sedimentary • Metamorphic

  3. The rock cycle • Interactions among Earth’s water, air, land, and living things can cause rocks to change from one type to another • A continuous process

  4. Igneous Rocks • Forms when lava or magma hardens. • Lava: • Molten rock on the surface of the Earth • Magma: • Molten rock beneath Earth’s surface.

  5. Igneous Rock Formation • Igneous rocks are formed by the cooling of molten rocks and the crystallization of minerals.

  6. Types of igneous rocks • Intrusive Igneous rock: forms when magma hardens beneath Earth’s surface • Extrusive Igneous Rock: forms when lava hardens on the surface of the Earth

  7. Classifying igneous rocks • Igneous Rocks are classified based on their texture and composition.

  8. Texture classification • Texture: size, shape, and arrangement of interlocking crystals. • Course Grained: slow cooling, large crystals. • Fine Grained: rapid cooling, small interconnected mineral grains. • Glassy: looks like glass, extrusive igneous rocks. Ex. Obsidian • Porphyrite: large crystals embedded in a matrix of much smaller crystals.

  9. Composition classification • Composition: based on proportions of light to dark minerals • Basaltic Composition • Contains many dark silicates minerals and plageoclase feldspar • Rich in magnesium and iron • Ex: basalt and gabbro • Granitic Composition • Made almost entirely of light-colored silicate minerals like quartz and feldspar • 0 to 25% dark minerals • Biotite and amphibole

  10. Composition classification • Andesitic Composition • Between basltic and granitic composition • At least 25% dark minerals • Ultramafic Composition • Composed mainly of iron and magnesium rich mineral • Almost entirely dark minerals

  11. Igneous chart

  12. What is a Sedimentary rock? • Forms when existing rocks are broken down into sediment then compacted and cemented together • Processes • Cementing • Compaction

  13. How do they form? • Weathering: Any process that break rocks into sediments • Erosion : The removal of weathered rocks • Deposition: when an agent of erosion (water, wind, ice, or gravity) loses energy, it drops the sediment • Compaction: is a process that squeezes or compacts sediments together • Cementation: takes place when dissolved minerals are deposited in the tiny spaces among the sediments

  14. Classification of sedimentary rocks • Classified by the way they form • Clastic or chemical

  15. Clastic sedimentary rocks • Made of weathered bits of rocks and minerals • Grouped according to the size of the sediment.

  16. Clastic sedimentary rocks

  17. Chemical sedimentary rocks • Form when dissolved minerals precipitate from water solution • Biochemical Sedimentary Rock: made from once living organisms (like shells and skeleton remains) • Ex: limestone, chalk, conquina, rock salt, and bituminous coal

  18. What is a metamorphic rock? • Form when existing rocks are changed by heat and pressure • Metamorphism: means “change form”

  19. What causes metamorphism? • Heat: provides the energy needed to drive chemical reactions which causes existing minerals to recrystallize • Pressure: applied in all directions on a rock which causes spaces between mineral grains to close • Hydrothermal Solutions: hot, water based solutions that promote recrystallization by dissolving original minerals and then depositing new ones

  20. Classification of Metamorphic Rocks • Classified by texture and composition • Foliated • Rock with layered or banded appearance • Ex: Gneiss • Nonfoliated • No layered or banded appearance • Contains only one mineral • Ex: Marble

  21. Classification of foliated metamorphic rocks

  22. Classification of non-foliated metamorphic rocks

More Related