Unit 2 Preparation (Definitions)

All the key terms on the study guide

Define HANGING WALL & FOOTWALL

Hanging wall: Rock ABOVE the fault

Footwall: Rock BELOW the fault

Describe a NORMAL fault

Caused by tension + moves DOWN (hanging wall)

Describe a REVERSE fault

Caused by compression + moves UP (hanging wall)

Describe a THRUST fault

Caused by compression + moves at a LOW ANGLE (hangwall moves up)

Describe a STRIKE-SLIP fault

Caused by shear + moves sideways

Describe a FAULT SCARP

A step/cliff made by a fault.

Describe a ARC VOLCANO

Chain of volcanoes (Above a subduction zone)

Describe an ISLAND ARC VOLCANO

Arc volcanoes on islands (Above a subduction zone)

Describe Wadati-Benioff Zone

Sinking plate = Earthquake

Describe Mid-Ocean Ridge

Plates seperate = new crust

Describe Continental Rift

Continents pull apart

Describe Hot Spot

Hot mantle creates magma & volcanoes

Define: Focus (Hypocenter) VS. Epicenter

Focus: Earthquake underground

Epicenter: Point directly above it (on the surface)

Define an earthquake

Ground shaking from sudden movements (sudden slipping under a fault)

Define Seismic Waves

Energy waves from an earthquake

What are the BODY waves & SURFACE waves

Body: P & S Waves

Surface: Love & Rayleigh

Note: P waves = parallel, S waves = perpendicular, L waves = side to side, R = Rolling/Up-and-Down

Define a YIELD POINT

A permanent change in the material (Shape)

Define Modified Mercalli Scale

Measures intensity

Define Richter Scale

Measures magnitude

Define Moment Magnitude Scale

Measures energy (released)

Define a TSUNAMI

Large ocean waves (due to underwater earthquakes)

Define an ANTICLINE & SYNCLINE

Anticline: Rock layers fold up (Rainbow shape)

Syncline: Rock layers fold down (Upside down rainbow shape)

Define Basin & Dome

Basin: Rock layers bend DOWN

Dome: Rock layers bend UP

Define a MINERAL (what it is)

Natural, Non-Living, Solid, Organized (Specific crystal structure), Specific (Composition)

Define an IGNEOUS ROCK

Formed by cooled magma/lava

Define a SEDIMENTARY ROCK

Formed by small pieces of rock (sediments) and organic material.

Define a METAMORPHIC ROCK

A solid rock changed by heat, pressure, or stress (no melting)

Define Bowen’s Reaction Series

The order of minerals as magma cools

Define ULTRAMAFIC

VERY low in Silica, Rich in Iron & Magnesium (Ex. Peroditie)

Define MAFIC

Low in Silica, Rich in Iron & Magnesium (Dark) (Ex. Extrusive: Basalt / Intrusive: Gabbro)

Define INTERMEDIATE

Medium in Silica (Ex. Extrusive: Andesite / Intrusive: Diorite)

Define FELSIC

High in Silica (Light) (Ex. Extrusive: Rhyolite / Intrusive: Granite)

Define Phaneritic & Aphanitic

Phaneritic: Big crystals + Slow cooling (Intrusive)

Aphanitic: Small crystals + Fast cooling (Extrusive)

Define Porphyritic

Large crystals + Small crystals (2 cooling stations)

Define Pyroclastic

Pieces from volcanic eruptions

Define Vesicular

Holes in rocks (due to gas being trapped inside)

Define Glassy

Fast cooling

Define Shield, Cinder cone, & Composite (Stratovolcano) volcanoes

1. Shield: Wide + Big (Mafic)

2. Cinder Cone: Small + Steep (Felsic)

3. Composite (Stratovolcano): Tall + Cone shaped (Intermediate)

Define Physical VS Chemical Weathering

Physical: Breaks rocks

Chemical: Changes minerals

Define SEDIMENTARY MATURITY

How much the sediment matured/changed

Define BEDS

Layers of sediments/rocks

Define CROSS-BEDS

Angled layers of sediments

Define GRADED-BEDS

Big/Coarse = Bottom / Small/Fine = Top

Define RIPPLE MARKS

Small ridges created by Water/Wind

Define MUD CRACKS

Mud dries, then cracks

Define SOIL

Sediments + Organic material

Define SOLID-STATE DIFFUSION

Atoms move/rearrange (but remain solid)

Define FOLIATION

Flat minerals LINE UP

Define MASS WASTING

Earth’s material moving downhill due to gravity

Define ROCK FALL / DEBRIS FALL / TOPPLES

Fall/Trip = Downhill (Tip downhill)

Define TALUS

Rock debris at the bottom of steep slopes

Define TRANSLATIONAL & ROTATIONAL Landslides

Translational: FLAT surface

Rotational: CURVED surface

(Materials slide)

Define DEBRIS FLOW

A mass of loose material flowing downhill

Define SOIL CREEP

VERY SLOW movement of soil moving downhill