Lava Color Viscosity Speed of Flow Rock Formed Silica Content high high slow light rhyolite low low fast dark basalt Magma Types Magma Properties Can Vary Not all magma is the same. The composition and viscosity of magma can vary. These properties affect how fast the lava flows and the type of volcano that forms. Although magma is a complex mixture, it is primarily composed of silica. Magma can contain from 50 to 70 percent silica. aa - high viscosity pahoehoe - low viscosity Magma Viscosity Viscosity is a liquid's resistance to flow. High viscosity magma is sticky and flows very slowly. Low viscosity magma flows more quickly. Temperature Affects Magma & Lava Higher temperatures make magma and lava more fluid, lowering the viscosity. Pahoehoe is a type of very hot, fast-moving lava with low viscosity. Slower- moving, cooler, high-viscosity lava is known as aa. quartz silica 50-70 % silica quartz silica 50-70 % silica 0 1400 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 temper atur e viscosit y Different Types of Lava Magma with high silica content has a higher viscosity and produces light-colored lava that later forms rhyolite. Magma with less silica and a lower viscosity produces dark lava that forms basalt. Properties of Magma © Copyright NewPath Learning. All Rights Reserved. 94-4535 Visit www.newpathlearning.com for Online Learning Resources. Some photos courtesy of USGS.
Pause and Review Complete the concept map for the properties of magma. Fill in the chart below. Properties of Magma © Copyright NewPath Learning. All Rights Reserved. 94-4535 Visit www.newpathlearning.com for Online Learning Resources. is and flows is and flows MAGMA viscosity types is composed of Lava Color Viscosity Speed of Flow Rock Formed Silica Content high low Magma Types