Mafic lava

Definition

Mafic lava is a type of lava that is rich in magnesium and iron, characterized by its darker color and relatively low viscosity. This type of lava typically flows easily and can cover large areas, leading to the formation of broad, shield volcanoes. Mafic lava is significant because it shapes the geology of various celestial bodies and influences volcanic activity across the solar system.

5 Must Know Facts For Your Next Test

1. Mafic lava has a lower silica content than felsic lava, which contributes to its fluidity and allows it to travel greater distances before solidifying.
2. The eruption of mafic lava typically produces less explosive volcanic activity compared to more viscous lavas, leading to different types of landforms.
3. Mafic lava is found on various celestial bodies, including the Moon and Mars, indicating that volcanism is a widespread phenomenon in the solar system.
4. The composition of mafic lava contributes to the formation of unique geological features like flood basalt provinces and large igneous provinces on Earth.
5. Mafic lavas can form pillow structures when they erupt underwater, showcasing their ability to adapt to different environments.

Review Questions

• How does the composition of mafic lava influence its physical properties and behavior during volcanic eruptions?
  • Mafic lava has a higher content of magnesium and iron and lower silica levels compared to other types of lava. This composition results in a lower viscosity, allowing it to flow more easily and cover larger areas. Because of this fluidity, mafic lava typically produces less explosive eruptions, leading to the formation of broad shield volcanoes rather than steep stratovolcanoes. The physical properties influenced by its composition play a crucial role in determining the nature of volcanic activity.
• Discuss how the presence of mafic lava affects the geological features observed on different planetary bodies within the solar system.
  • Mafic lava significantly influences the geological features seen on various celestial bodies. On Earth, it leads to broad shield volcanoes and extensive basalt plateaus, while on Mars, large flood basalts can be traced back to ancient mafic volcanic activity. The Moon also showcases vast plains called 'maria,' which were formed by ancient mafic lava flows. Studying these features helps scientists understand volcanic history and tectonic processes across the solar system.
• Evaluate the implications of mafic lava flows for understanding past volcanic activity on other planets and how it informs our knowledge of planetary evolution.
  • The study of mafic lava flows on planets like Mars and Venus provides key insights into their volcanic histories and geological evolution. These flows indicate past geothermal activity and can suggest whether these bodies may have had conditions suitable for life. By evaluating the characteristics and distribution of mafic lavas across different planets, researchers can make inferences about tectonic movements, atmospheres, and potential habitability. Understanding these patterns enhances our knowledge about planetary processes and how they compare to Earth's geology.

Related terms

Basalt: A common type of mafic rock that forms from the rapid cooling of mafic lava, characterized by its fine-grained texture and dark color.

Shield Volcano: A type of volcano built primarily by the flow of low-viscosity mafic lava, resulting in broad, gentle slopes.

Volcanism: The process by which magma from within the Earth's mantle reaches the surface, resulting in the eruption of lava, ash, and gases.