Study your flashcards anywhere!

Download the official Cram app for free >

  • Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off

How to study your flashcards.

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

A key: Read text to speech.a key


Play button


Play button




Click to flip

22 Cards in this Set

  • Front
  • Back
molten rocks formed deep below the surface of the earth
molten rocks formed at or near the surface of the earth
Phaneritic texture:
course-grained; took a long time to cool and crystals had time to form
Aphanitic texture:
fine-grained (can't see the texture); it cooled very quickly in volcanic environments
Porphyritic texture:
composed of at least 2 minerals having a big difference in grain size
What are the two stages of porphyritic texture?
large phenocysts form deep inside the earth; matrix grains crystallize closer to Earth's surface
Glassy texture:
non-crystalline with no mineral grains because they had no time to crystallize; display conchoidal fracture
vesicular texture:
refers to holes, pores, or cavities within the igneous rock; the result of gas expansion
pyroclastic texture:
numerous grains or fragments welded together by heat of volcanic eruption
What is the range of silica for felsic rocks?
What is the range of silica for intermediate rocks?
What is the range of silica for mafic rocks?
What is the range of silica for ultra-mafic rocks?
less than 45%
What color are felsic rocks and where are they formed?
light; continents
What color are mafic rocks and where are they formed?
dark; oceans
concordant, mushroom-shaped; pushes up but doesn't break through
usually discordant; must be 100 sq. km; largest of all intrusive, plutonic strucutures; majority contain felsic or intermediate magma
concordant; shaped like a table
discordant; cuts across existing rock layers; flat like a table
same basic minerals, but crystals are much larger in size; few inches to several hundred ft thick
process that the hot batholith pluton alters the surrounding country rock
occurs in the country rock; process of detaching pieces of country rock by rising magma