Question

consider these statements regarding the examples of Igneous rocks,

1. Granite and Gabbro are types of igneous rocks.
2. Breccia and Tuff are categorized as igneous rocks
3. Basalt is formed from the solidification of magma.

• A. iii only
• B. All of these
• C. ii, iii
• D. ii only

Answer 1

Answer:

B. All of these

Igneous Rocks: Examples and Formation

Understanding Igneous Rocks

• Igneous rocks are formed through the cooling and solidification of molten rock (magma or lava).

• They are one of the three main rock types, alongside sedimentary and metamorphic rocks.

Statement 1: Granite and Gabbro

• Granite is a common type of intrusive igneous rock. It forms when magma cools slowly beneath the Earth's surface. It is typically coarse-grained and composed mainly of quartz, feldspar, and mica.

• Gabbro is also an intrusive igneous rock, forming from the slow cooling of magma deep within the Earth. It is a coarse-grained rock, darker in color than granite, and rich in minerals like pyroxene and plagioclase feldspar. Both are classic examples often cited in geology.

Statement 2: Breccia and Tuff

• Breccia is a clastic sedimentary rock, formed from angular fragments of pre-existing rocks cemented together. It is not an igneous rock.

• Tuff is a type of igneous rock, specifically an extrusive igneous rock. It is formed from volcanic ash and small fragments of rock that are ejected during a volcanic eruption and then solidify. While Breccia is sedimentary, Tuff is indeed igneous.

Statement 3: Basalt Formation

• Basalt is a common extrusive igneous rock. It forms when lava cools and solidifies rapidly on the Earth's surface after a volcanic eruption. The rapid cooling results in a fine-grained texture.

• The process described (solidification of magma/lava) is the fundamental way igneous rocks are formed.