WHAT HAPPENS AFTER MAGMA IS FORMED | Magma Formation | Earth Science

Summary

The video explains the behavior and transformation of magma after its formation, discussing factors such as temperature, viscosity, and gas content. It covers magma generation processes, how density influences magma movement, and the role of viscosity in determining magma flow. The video also introduces Bowen's Reaction Series, explaining the crystallization of minerals as magma cools and differentiates into various types of rocks. Other key topics include magmatic differentiation, crystal fractionation, partial melting, magma mixing, and assimilation of surrounding rocks as magma rises. These processes shape the diversity of igneous rocks found on Earth.

Takeaways

• 🌋 Different types of magma have varying chemical compositions, temperatures, viscosities, and gas contents, influencing their formation and behavior.
• 💧 Magma rises due to its lower density compared to the surrounding rock, similar to how a rock sinks and a styrofoam floats in water.
• 🔥 Viscosity is key in determining how magma flows; high temperature and low silica content result in lower viscosity, making the magma flow more easily.
• ⛰️ Mafic magma is less viscous than silicic magma due to its higher temperature and lower silica content, leading to easier flow.
• 🌡️ The Bowen's reaction series explains how minerals crystallize from magma at different temperatures, with higher-temperature minerals forming first.
• 🧱 Magma can either be ejected through volcanoes or solidify beneath the surface, forming intrusive igneous rocks.
• 🌿 Magmatic differentiation refers to processes like crystal fractionation, partial melting, and magma mixing, which create different magma compositions from a single source.
• 🪨 Crystal fractionation happens when denser minerals crystallize first, settling out and leaving the remaining magma more silicic.
• 🌋 Magma mixing occurs when two types of magma merge, generating a single intermediate magma composition.
• 🌍 Assimilation involves magma incorporating surrounding crustal rocks, altering its chemical composition as it rises to the surface.

Q & A

What are the four factors that affect magma formation?

The four factors that affect magma formation are temperature, viscosity, gas content, and chemical composition.

Which type of magma has the highest viscosity and gas content?

Rhyolitic magma has the highest viscosity and gas content.

How does magma rise through the Earth's crust?

Magma rises through the Earth's crust due to its lower density compared to the surrounding rock. The difference in density creates buoyancy, allowing the magma to move upward.

What happens to magma at shallower levels if its density becomes similar to the surrounding rock?

At shallower levels, if the magma's density becomes similar to the surrounding rock, it reaches equilibrium, stops rising, and begins to accumulate and solidify.

How does viscosity affect the flow of magma?

Viscosity measures a fluid's resistance to flow. Magmas with lower viscosity flow more easily, while magmas with higher viscosity are more resistant to flow.

What is the relationship between temperature, silica content, and viscosity in magma?

Temperature and viscosity have an inverse relationship, meaning higher temperature lowers viscosity. Silica content and viscosity have a direct relationship, meaning higher silica content increases viscosity.

What is Bowen's Reaction Series, and what does it explain?

Bowen's Reaction Series is an idealized progression that explains how certain minerals form as magma cools. It describes the crystallization sequence of minerals based on their stability at different temperatures.

What are the two branches in Bowen's Reaction Series?

The two branches in Bowen's Reaction Series are the continuous branch and the discontinuous branch. These branches occur simultaneously as magma cools and minerals crystallize.

What is crystal fractionation, and how does it affect magma composition?

Crystal fractionation is the process by which the composition of magma changes as denser minerals crystallize first and settle, leaving the remaining magma more silicic (richer in silica).

What is magma mixing, and when does it occur?

Magma mixing occurs when two different magmas rise together, and the more buoyant magma overtakes the slower-rising one, resulting in a single intermediate magma.