Composition of Lava

Lava is primarily composed of silicate minerals, such as feldspar, pyroxene, and olivine. The composition of lava can vary depending on the type of volcano and the geological processes involved.

Types of Lava

There are different types of lava based on their composition and viscosity:

• Basaltic Lava: This type of lava is low in viscosity and flows easily. It often forms shield volcanoes and is commonly found at divergent plate boundaries.
• Andesitic Lava: Andesitic lava has higher viscosity and can lead to explosive eruptions. It is associated with stratovolcanoes and convergent plate boundaries.
• Rhyolitic Lava: Rhyolitic lava is highly viscous and can result in violent eruptions, forming lava domes and pyroclastic flows. It is often found at continental hotspots.

Lava Eruptions

Volcanic eruptions can be classified based on the type of lava they produce:

• Effusive Eruptions: These eruptions involve the outpouring of lava in relatively gentle flows, often associated with shield volcanoes.
• Explosive Eruptions: Explosive eruptions involve the ejection of ash, rock fragments, and gases, often resulting from high-viscosity lava.

Landforms Created by Lava

Lava can create various landforms, including:

• Lava Flows: These are streams of molten rock that can cover large areas as they cool and solidify.
• Volcanic Cones: The accumulation of lava and volcanic materials can form volcanic cones, such as shield volcanoes, stratovolcanoes, and cinder cones.
• Lava Plateaus: Extensive lava flows can create large plateaus when they cover a widespread area.
• Lava Domes: Thick, viscous lava can form steep-sided domes as it piles up around a vent.

Study Guide: Understanding Lava

To understand lava, students should focus on the following key points:

1. Define the composition and properties of lava.
2. Compare and contrast the types of lava based on their viscosity and eruption characteristics.
3. Explain the different types of volcanic eruptions and their association with specific lava compositions.
4. Identify and describe the landforms created by lava flows and eruptions.
5. Discuss the impact of volcanic activity and lava flows on the environment and human communities.

[Lava] Related Worksheets and Study Guides:

• VolcanoesScience • Eighth Grade
• VolcanoesScience • Seventh Grade