Basaltic Lava

Basaltic lava is a type of lava that is associated with basalt, a common extrusive igneous rock. This type of lava is characterized by its low viscosity and high fluidity, which allows it to flow over long distances before solidifying. Basaltic lava is commonly associated with volcanic activity in shield volcanoes, such as those found in Hawaii.

Composition

Basaltic lava is primarily composed of basalt, which is a fine-grained, mafic igneous rock. It is rich in iron and magnesium minerals, giving it a dark color. The high iron content is responsible for the black color of basaltic lava flows.

Characteristics

Basaltic lava has several distinctive characteristics:

• Low viscosity: Basaltic lava has a low viscosity, meaning that it flows easily. This results in long, fluid lava flows that can cover large areas.
• High temperature: Basaltic lava is typically very hot, with temperatures ranging from 1000°C to 1200°C.
• Pahoehoe and Aa: Basaltic lava can form two distinct surface textures: pahoehoe, which is smooth and rope-like, and aa, which is rough and blocky.

Volcanic Features

Basaltic lava is associated with several volcanic features, including:

• Shield volcanoes: Basaltic lava flows are often found in shield volcanoes, which have broad, gently sloping profiles due to the fluid nature of the lava.
• Lava tubes: Basaltic lava can form lava tubes, which are natural conduits through which lava travels beneath the surface.
• Lava fields: Extensive areas covered by basaltic lava flows are known as lava fields or lava plains.

Study Guide

When studying basaltic lava, consider the following key points:

1. Describe the composition of basaltic lava and the minerals it contains.
2. Explain the characteristics of basaltic lava, including its viscosity, temperature, and surface textures.
3. Discuss the volcanic features associated with basaltic lava, such as shield volcanoes, lava tubes, and lava fields.
4. Compare and contrast basaltic lava with other types of lava, such as andesitic and rhyolitic lava.
5. Examine the environmental impacts and uses of basaltic lava, such as its effects on landscapes and its potential for use in construction materials.