Shield Volcano Lab Review

1
Shield Volcano Lab Review

• Activity 4 Geologic Field Notebook

2

• Which magma created the highest viscosity lava?
• Which magma created the lowest viscosity lava?
• Why would different lab groups get different
  results?
• Would you say that lavas erupted by Hawaiian
  volcanoes are high or low viscosity?
• Fairly low because they move easily.

3

• How does the low viscosity lava affect the shape
  of a shield volcano?
• The lava spreads out which creates a more broad
  shape.
• Do you think these lavas had a high or low silica
  content?
• They have a low silica content because they have
  a low viscosity. High silica content lavas have
  a high viscosity.

4

• What color rock does low silica lava create?
• The low silica rock in the Hawaiian shield
  volcanoes creates dark rocks.
• What do you know about how temperature of a fluid
  affects that fluids viscosity?
• Generally the higher the temperature, the lower
  the viscosity or the more easily it flows.

5

• Now think back to the model of the Earth. Where
  is the mantle hotter? Near the surface or deeper?
• The mantle is hotter the deeper it is in the
  Earth.
• Where in the mantle would the lava in shield
  volcanoes come from?
• The mantle in shield volcanoes would come from
  deeper in the mantle because it is hotter and it
  flows easily.(low viscosity)