Physical Geology Composition of materials, tectonic cycle, Formation and identification of rock types

The Rock Cycle The rock cycle is the continuous destruction and formation of rocks from one form to another driven by geologic forces 3 Types of Rocks Igneous Rocks Sedimentary Rocks Metamorphic Rocks

The Rock Cycle The parent material of all rock is magma. Magma is molten rock underneath the Earth’s surface Lava is molten rock above the Earth’s surface Why is this considered the parent source?

The Rock Cycle Once magma cools and crystallizes, it forms Igneous Rocks Igneous Rocks, like all other rocks, can be broken down (weathered) into smaller fragments of rocks

The Rock Cycle Once the rocks are weathered, they are transported to various locations. The transport of materials is referred to as erosion. After new materials are eroded, they are dropped off in their new locations. The dropping of sediments is referred to as deposition.

The Rock Cycle Sediments then undergo processes that eventually form sedimentary rocks. Sediments are pressed together through processes of compaction The compacted sediments stay together through cementation

The Rock Cycle Once rocks are formed, they undergo extensive heat and pressure to become metamorphic rocks. Metamorphic rocks can be weathered into sediments or melted into magma as they transform into other rock types

Things to Consider All Igneous rocks are formed from the cooling and crystallization of magma. All Sedimentary rocks are made through the processes of compaction, cementation, and lithification. All Metamorphic rocks are formed from heat and pressure.

Tectonics, earthquakes & volcanoes Earth’s Interior Tectonics, earthquakes & volcanoes

Interior structure The Earth is divided into several layers based on similar temperatures, materials, pressure, and depth

Interior Structure The materials that make up the Earth separated as the Earth cooled. The lighter materials rose to the surface and the heavier materials sunk to the center. Movement of heavy metals in the liquid outer core is responsible for the Earth’s magnetic field.

Interior Structure HOT MATERIAL RISES, COOL MATERIAL SINKS The mantle of the Earth is made of a mixture of hard, rigid rocks in the lower mantle and plastic, more flexible rocks in the upper mantle. The differences in temperature between the upper and lower portions of the mantle plus the flexibility of the upper mantle cause currents of material that move the crust above the mantle. HOT MATERIAL RISES, COOL MATERIAL SINKS

Interior structure The crust of the Earth is broken up into sections called tectonic plates made up of the lithosphere.

Interior Structure Oceanic crust is heavier and more dense so it sinks and stays below the water. Continental crust is lighter and less dense so it rises above the water.

Plate Tectonics History of plate movement based on current evidence.

Plate tectonic movement

Plate movement Plates meet at locations called plate boundaries. Where these plates meet movement causes activities like earthquakes, volcanoes, and mountain building

Plate movement Divergent Boundaries: places where the tectonic plates are moving apart Examples: mid-ocean ridges, rift valleys

Plate movement Divergent Boundaries Seafloor spreading: as oceanic plates move apart new ocean floor is built by cooling lava

Plate movement Divergent Boundaries Continental Rift Valleys: places in the middle of a continental plate where spreading is occurring

Plate movement Convergent Boundaries: plate boundaries where two plates are moving together - Types of convergent boundaries rely on the type of crust that is being moved together

Plate movement Convergent Boundaries Oceanic vs. Continental -forms where a piece of oceanic crust is subducted (pulled under)beneath a section of continental crust Subduction zone: Ocean plate slides under continental plate and forms a deep-ocean trench and continental volcanic arc

Plate movement Convergent Boundaries Oceanic vs. Oceanic - Forms when one oceanic plate is subducted under another oceanic plate. - Creates a deep ocean trench and a volcanic island arc

Plate movement Convergent Boundaries Continental vs. Continental - Forms when two continental plates collide and form mountain ridges

Plate movement India and Eurasia Collision

Plate Movement Transform Fault Boundary: plate boundary where two plates move past each other along a fault (break in the crust) - High numbers of earthquakes occur in these areas Example: San Andreas Fault

Evidence of plate tectonics Earthquake: shaking and trembling that results from sudden movement of part of the Earth’s crust Reasons Why Earthquakes Occur: - Volcanic eruption -collapse of a cavern -impact of meteor -major cause: stress that builds up and causes faulting

earthquakes Common Earthquake Locations Most earthquakes occur along plate boundaries Pacific ring of fire: an area surrounding the pacific ocean with a high concentration of earthquakes and volcanoes.

Tectonic plate movement Tsunami: series of large waves caused by the displacement of a large volume of water - Often triggered by earthquakes, volcanic eruptions, landslides, or glaciers breaking

Evidence of plate tectonics Volcanism: any activity that includes the movement of magma toward the surface of the Earth Volcano: a place where magma comes to the surface