Types of Lava

• Lava Textures

  Vesicular, Pumice, Amygdaloidal, Columnar Jointing
• Lava

  Pillow Lava, Pahoehoe, Aa
• Lava Flows


  Lava Tubes
• Pillow Lava


  Formed by underwater eruptions lf mafic magma

  Glassy on outside and fine grained on the inside
• Pahoehoe


  As the external layer of rock cools and solidifies it forms a rope like pattern of rock as the liquid lava continues to move underneath
• Aa


  Made of sharp, angular and jagged blocks of basalt

  Cooked surface layer breaks up into these fragments as molten lava continues to flow underneath
• Lava Tubes


  Sub-surface tunnels within lava flows that have been formed as the fluid lava has continued to flow down slope

  Solid top and base is formed as it cools and solidified against the ground and atmosphere
• Pumice


  Highly vesicular rhyolite, so light that it flows on water
• Columnar Jointing


  Forms when thick lava flows, cools more slowly. As it cools, Seperate cooling centres develop and the rock contracts towards these centres producing a polygonal pattern of vertical joints