North Carolina General Contractors Practice Exam

Igneous rock is formed from what material?

1. Molten magma

2. Compressed sediments

3. Weathered rock fragments

4. Liquid metals

The correct answer is: Molten magma

Igneous rock is formed from molten magma, which results from the cooling and solidification of hot, molten material within the Earth or at its surface. When magma rises to the surface and erupts as lava, it cools rapidly, forming extrusive igneous rocks like basalt or pumice. Alternatively, when magma cools slowly below the surface, it forms intrusive igneous rocks such as granite. This process is distinct from the formation of sedimentary or metamorphic rocks, which arise from different geological processes, such as the compaction of sediments or the transformation of existing rock under heat and pressure. Understanding that igneous rocks originate from molten material emphasizes the role of volcanic activity and the Earth's internal heat in shaping the crust.