Magmatism is a process of formation and movement of magma, which is mostly composed of elements silicon and oxygen. This process happens in the interior of the Earth when solid rocks melt through the process of melting. The process is affected by three factors, namely: 1. pressure in a process known as decompression which happens in the mantle; 2. temperature in a process known as heating which happens in the crust; and 3. composition in a process known as assimilation which happens in the crust. When magma is erupted from a volcano, it is called lava. When it cooled and solidified, it becomes igneous rock.
Magmatism is a process of formation and movement of magma, which is mostly composed of elements silicon and oxygen. This process happens in the interior of the Earth when solid rocks melt through the process of melting. The process is affected by three factors, namely: 1. pressure in a process known as decompression which happens in the mantle; 2. temperature in a process known as heating which happens in the crust; and 3. composition in a process known as assimilation which happens in the crust. When magma is erupted from a volcano, it is called lava. When it cooled and solidified, it becomes igneous rock
The Correct Answer and Explanation is:
Corrected Version:
Magmatism is the process of formation and movement of magma, which is primarily composed of the elements silicon and oxygen. This process occurs in the Earth’s interior when solid rocks undergo partial melting. Three main factors influence the formation of magma:
- Pressure – In a process known as decompression melting, pressure decreases, typically in the mantle, allowing rocks to melt.
- Temperature – In a process called thermal melting, increasing temperature, often in the crust, causes rocks to melt.
- Composition – In a process known as assimilation, the incorporation of surrounding rock material (with different chemical compositions) into the magma can alter its melting point and facilitate melting, usually occurring in the crust.
When magma erupts from a volcano, it is called lava. Once it cools and solidifies, it forms igneous rock.
Explanation:
Magmatism is a fundamental geological process responsible for the generation and movement of magma within the Earth. Magma is a molten or partially molten mixture of rocks, dominantly made up of silicon (Si) and oxygen (O), which together form silicate minerals. This process plays a crucial role in the rock cycle and the formation of the Earth’s crust.
Magma forms through partial melting of solid rock in the Earth’s mantle or crust. Three primary factors control this melting:
- Decompression melting occurs when hot mantle rocks rise toward the surface. As pressure decreases with ascent, rocks can melt without a temperature increase. This commonly happens at mid-ocean ridges and mantle plumes.
- Thermal melting (or heating) involves an increase in temperature that causes rocks to melt. This often occurs when mantle-derived magma intrudes into the crust and heats surrounding rocks.
- Assimilation involves the melting and incorporation of surrounding rock material into the magma. This can change the magma’s composition and lower the melting point, enhancing magma production.
Once magma reaches the surface through volcanic eruptions, it is known as lava. As lava cools and crystallizes, it forms igneous rocks, which are classified as either intrusive (if they solidify beneath the surface) or extrusive (if they solidify after eruption).
Understanding magmatism helps geologists study volcanic activity, the formation of new crust, and the thermal evolution of the Earth.
