Geology of Plutonism and Volcanism

Plutonism

• Plutonism encompasses all igneous geological activities occurring below Earth's surface.
• Magma intrusion into the crust, unable to reach the surface, creates ideal conditions for metallogenesis (formation of ore deposits).
• Essential components like oxides, fluorine, sulfur, and chlorine are necessary for magma creation.
• Magma solidifies and crystallizes predominantly within Earth's interior.

Volcanism

• Volcanism describes geological phenomena on Earth's surface, including volcano formation and hot springs.
• It involves the flow and transportation of igneous material from the planet's interior to the surface.
• Movement occurs through cracks (natural pipes) within the upper mantle.
• This process can extend to the terrestrial surface in various instances.

Magma Formation

• Magma formation, or melting, involves pressure and temperature changes within Earth.
• Decompression melting: Melting happens when a rock's pressure decreases while temperature remains roughly constant. This is often in upward movement of mantle material (or near the surface).
• Flux melting: Melting occurs when substances like water or carbon dioxide are added to the rock, lowering its melting point. This is particularly significant when the magma passes through the crust in relation to the surrounding rocks.
• Temperature greatly impacts the nature of the resultant magma.
  • At extremely high temperatures (over 1300°C), magma is largely liquid due to sufficient atomic energy.
  • As temperature decreases, silica tetrahedra formation and chain formation (polymerization) lead to higher viscosity, influencing volcanic eruption dynamics.

Magma After Formation

• After magma is formed, it can either intrude or extrude.
• Intrusion: Magma moves up into a volcano without erupting; it causes growth on the inside, similar to a balloon.
• Extrusion: Magma erupts, causing surface land formations (volcanoes) through the release of built-up gas pressure and cracks in the crust.

Factors Influencing Volcanic Eruptions

• Magma chamber depth influences the strength and intensity of volcanic eruptions.
  • Deeper magma chambers result in more powerful eruptions.
• The presence of water vapor and gases in the magma chamber plays a crucial role in eruption dynamics.
• Increased pressure due to magma and gases propels magma upwards.
• Volcanic activity and igneous rock formation are directly related to the processes and products described.