1. Properties of Magma Chapter 3-2

2. Viscosity Liquids resistance to flow Magma’s viscosity varies Depends on temperature and silica content The higher the silica content, the higher the viscosity The higher the temperature, the lower the viscosity

3. Viscosity Silica is a major ingredient in magma (50%-70%) High silica content high viscosity (slow) light colored lava Ex: rhyolite Low silica content low viscosity (fast) Dark colored lava Ex: basalt

4. Temperature Temperature of magma/lava can range from 750°C to 1,175°C The hotter the magma, the lower the viscosity (flows faster) The cooler the magma, the higher the viscosity (flows slowly)

5. Types of Lava pahoehoe Fast moving Hot Low viscosity Looks like a mass of wrinkles, billows, and rope-like coils aa Slower moving Cooler High viscosity Forms rough surface of jagged lava rocks