Volcanology

1. Basaltic
   1. From oceanic plate
2. Andesetic
3. Rhyolitic

1. Decompression melting
   1. Pressure
2. Flux melting
   1. Addition of water
      1. Lowers temperature
3. Transfer of heat

1. Andesitic and rhyolitic lava flows
   1. Siliceous lava flows
      1. Thick stubby flows that does not move far from the vent
2. Basaltic Lava
   1. Pahoehoe flow

      Nota:

      • As basaltic lava flow are exposed to the atmosphere and cools, it advances as a series of small lobes and toes that cotinually break out from a cooled crust
      1. Bizarre shapes
   2. Aa flow

      Nota:

      • Higher viscous basaltic and andesitic lava, while cooling forms a rough surface composed of broken lava blocks. The surface may cool, but the interior remains molten and continue to advance.
      1. Jumbled mass of angular blocks
   3. Pillow lava flow

      Nota:

      • Surface of basaltic lava cool quickly under water, while the inside is still molten. The surface cracks and the molten magma oozes out. The process continues resulting in piles of lava pillow stacked above one another
      1. Elongated, interconnected flow lobes that are circular in cross section

Nota:

• Super dangerous! Can kill organisms by direct ingestion or by absorption onto plants followed by ingestions by organisms

1. Carbon dioxide, chlorine, sulfur and fluorine gases

Nota:

• Explosive bursting of bubbles will fragment the magma into clots of liquid that cool as they fall through the air

1. Ash and dust
2. Volcanic bombs and lapilli

   Nota:

   • Lava fragments that were ejected, consist mostly of gas bubbles
3. Tephra fall

   Nota:

   • Clouds of gas and tephra that rise above a volcano produce an eruption column that can rise up to 45km , picked up by the wind, and eventually fall to the surface after being carried for some distance
4. Volcanic block

   Nota:

   • Solic rock fragment greater than 64mm in diameter that was ejected from a volcano. Consist of solidified pieces of old lava flows from a volcano's cone
5. Pyroclastic flow

Nota:

• Formed by non-explosive low viscosity basaltic magma

1. Gentle upper slopes, steeper lower slopes
2. Thin lava flows built up over a central vent

Nota:

• Short viscuous lava

1. Steep upper slopes, gentle lower slopes