lab 5 igneous rocks
Download
Skip this Video
Download Presentation
Lab 5 – Igneous Rocks

Loading in 2 Seconds...

play fullscreen
1 / 11

Lab 5 – Igneous Rocks - PowerPoint PPT Presentation


  • 258 Views
  • Uploaded on

Lab 5 – Igneous Rocks. Volcanic hazards Tungurahua, near Banos, Ecuador. Igneous rocks. Igneous rocks – formed from cooled molten rock Intrusive (magma) – coarse grained Extrusive (lava) – fine grained Two stages – fine grained matrix with larger crystals (phenocrysts).

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Lab 5 – Igneous Rocks' - natan


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
  • Igneous rocks – formed from cooled molten rock
  • Intrusive (magma) – coarse grained
  • Extrusive (lava) – fine grained
  • Two stages – fine grained matrix with larger crystals (phenocrysts)
igneous textures
Igneous Textures
  • Glassy texture – very rapid cooling of viscous lava  volcanic glass
  • Aphanitic texture – rapid cooling, ign. rocks with crystals too small to see (fine grained)
  • Phaneritic texture – slow cooling, ign. rocks with crystals that are visible (coarse grained 1-10mm)
igneous textures1
Igneous Textures
  • Pegmatitic texture – last to cool, very course grained crystals (>1cm)
  • Porphyritic texture – represents two periods of cooling, composed of large crystals (phenocrysts) in a fine grained matrix
  • Vesicular texture – ign. rocks with vesicles in them  cause by gas bubbles being trapped in the cooling lava.
slide8
Aphanitic

Phaneritic

Glassy

Porphyritic

Vesicular

Pegmatitic

felsic v mafic
Felsic v. Mafic
  • Felsic
    • Quartz, plagioclase feldspar, K-spar, and muscovite
    • Light in color (generally)
  • Mafic
    • Biotite, amphibole, pyroxene, and olivine
    • Dark in color (generally)
how to identify
How to Identify
  • Identify color (light/dark), but be careful!
  • Identify the minerals in the rock (if it’s not too fine grained)
  • Identify textures
  • Classify the rock using the flow chart in Fig. 5.2 and Fig. 5.3
ad