Earth Science: Tectonic Plates Overview

Earth's Layers

• Earth has a layered structure, including the crust, mantle, outer core, and inner core.
• These layers differ in composition and density.

Tectonic Plates and Theories

• Earth's lithosphere is divided into numerous tectonic plates.
• Plate tectonics theory explains the movement and interaction of these plates.
• Evidence for plate tectonics includes:
  • Matching coastlines of continents.
  • Distribution of fossils and rocks.
  • Geological features like mountain ranges and volcanoes.
  • Earthquakes and volcanoes occurring along plate boundaries.

Tectonic Plate Movement

• Plates move slowly over Earth's mantle.
• The movement is driven by convection currents in the mantle.

Three Tectonic Boundary Types and Their Interactions

• Convergent Boundaries: Plates collide, leading to mountain ranges, volcanoes, and deep ocean trenches. Different outcomes depend on the type of crust involved.
• Divergent Boundaries: Plates move apart, forming new crust, ridges and rift valleys.
• Transform Boundaries: Plates slide past each other, causing earthquakes.

Minerals

• Minerals are naturally occurring, inorganic solids with a specific chemical composition and crystal structure.
• Minerals have unique properties, including:
  • Color
  • Hardness
  • Cleavage
  • Luster

Three Rock Types and Their Formation

• Igneous Rocks: Formed from cooled and solidified magma or lava.
• Sedimentary Rocks: Formed from the accumulation and cementation of sediments.
• Metamorphic Rocks: Formed from existing rocks changed by heat, pressure, or chemical reactions.

The Rock Cycle

• The rock cycle describes the continuous process of transformation between these three main rock types.
• Processes include weathering, erosion, melting, and solidification.