Igneous rocks
This presentation is the property of its rightful owner.
Sponsored Links
1 / 14

Igneous Rocks PowerPoint PPT Presentation


  • 39 Views
  • Uploaded on
  • Presentation posted in: General

Igneous Rocks. “Liquid Hot Magma!”. Igneous Rocks. Rocks formed from cooling of lava or magma Lava-Melted rock erupted from volcanoes and deposited on the earth’s surface. Cools quickly. Magma-Melted rock that sits inside the earth in a magma chamber. Cools slowly. Magma Chamber.

Download Presentation

Igneous 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.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Igneous rocks

Igneous Rocks

“Liquid Hot Magma!”


Igneous rocks1

Igneous Rocks

  • Rocks formed from cooling of lava or magma

  • Lava-Melted rock erupted from volcanoes and deposited on the earth’s surface. Cools quickly.

  • Magma-Melted rock that sits inside the earth in a magma chamber. Cools slowly.

Magma Chamber


Types of igneous rocks

Types of Igneous Rocks

  • 2 major types: Intrusive and Extrusive

  • Intrusive igneous rocks cool and harden inside the earth.

  • Extrusive igneous rocks cool and harden on the earth’s surface or outside the earth.


Intrusive igneous rocks

Intrusive Igneous Rocks

  • Form when magma cools before reaching the surface.

    • Cool very slowly

    • Intrusive igneous rocks have large, interlocking crystals because they cooled slowly inside the earth.

    • Examples are Granite, Gabbro, Diorite, and Unakite (Virginia’s State Rock!)

Granite

  • Unakite


Extrusive igneous rocks

Extrusive Igneous Rocks

  • Form when lava erupts and hardens on the surface.

    • Cool very quickly

    • Extrusive igneous rocks have fine (small) to no crystal grains at all.

    • A rock with no visible grains is called a volcanic glass (examples are pumice and obsidian).

    • Examples are Obsidian, Pumice, Scoria, Basalt, Tuff, Porphyry (cools inside then erupts), Rhyolite, Andesite.

Rhyolite

Obsidian


Texture of igneous rocks

Texture of Igneous Rocks

  • Grain Size (Glassy, Fine, Medium, Coarse)

  • Grain Shape (Irregular, Angular)

  • Sorting:

    • Glassy: Looks like glass (Obsidian, Pumice)

    • Aphanitic: Can’t see crystals (Scoria, Tuff)

    • Porphyritic: Large crystals in fine matrix (Porphyry)

    • Phaneritic: Medium to Large interlocking crystals (Granite, Diorite, Gabbro)


Textures

Textures

Glassy

Phaneritic

Aphanitic

Porphyritic


Vesicles

Vesicles

  • Vesicles are holes found ONLY in Igneous rocks.

  • Formed from trapped gasses when lava erupts

  • Examples: Scoria, Pumice, Basalt (sometimes)


Tectonic plate boundaries

Tectonic Plate Boundaries

  • Places where tectonic plates converge, diverge, or slip past each other.


Igneous rocks form at convergent boundaries

Igneous Rocks form at Convergent Boundaries

  • Ocean-Continent Convergent Boundary.

  • Forms volcanoes like those in Washington State.


Igneous rocks form at divergent boundaries

Igneous Rocks form at Divergent Boundaries

  • Divergent Boundary or Spreading Ridge

  • Forms volcanoes like those that make up Iceland and the mid-Atlantic Ridge.


Mid atlantic ridge

Mid-Atlantic Ridge


Igneous rocks form at hot spots

Igneous Rocks Form at Hot Spots

  • A hot spot is where magma rises to the surface in the middle of a plate and not a plate boundary.

  • Forms volcanoes like those in Hawaii or Yellowstone.


Hot spots

Hot Spots

Hawaii

Yellowstone


  • Login