PSS/EVSC 201 Introduction to Geology Exam 3 Study Guide

A set of 80 flashcards covering key vocabulary and concepts in geology related to mass wasting and metamorphic rocks, assisting students in exam preparation.

Differential stress

Tends to deform objects into oblong or flattened forms.

Protolith

The original rock from which a metamorphic rock forms, also known as parent rock.

Regional metamorphism

Type of metamorphism commonly associated with mountain building at convergent plate boundaries.

Correlation of rock layers

The process of matching rocks from different locations based on physical continuity, similarity of rock types, or fossil assemblages.

Mass wasting

Refers to the movement of soil, rock, and debris down a slope due to gravity.

Driving force for mass wasting

Gravity is the primary driving force behind mass wasting events.

Shear strength

Resistance to movement or deformation of soil, affected by water content.

Debris flow

A rapidly moving, turbulent mass of broken-up bedrock and debris.

Creep

The very slow downslope movement of soil and debris.

Contact metamorphism

Characterized by high temperatures without significant differential stress.

Foliation

The alignment of mineral grains in metamorphic rocks, which indicates the texture of the rock.

Progressive metamorphism of shale

The transformation sequence begins with shale, then slate, then phyllite, followed by schist.

Mudflow

A flowing mixture of soil and water, typically moving down a channel.

Earthflow

Soil moving downslope as a coherent mass.

Pore pressure

Refers to the effect of water that forces soil grains apart.

Soil saturation

When soil is completely saturated with water, it becomes heavier and less viscous.

Landslide

A general term that encompasses various types of mass wasting events.

Rotational slide

Movement along a curved surface.

Solifluction

The gradual flow of water-saturated soil over impermeable material.

Debris avalanche

A rapid downslope movement of debris and other materials.

Normal force of gravity

The force acting perpendicular to the slope that holds material in place.

Permafrost

Material that remains continuously frozen for many years.

Talus

An apron of fallen rock fragments found at the base of a slope affected by rockfall.

Hydrostatic pressure

Pressure exerted by fluids at equilibrium due to the force of gravity.

Earthflow characteristics

Flow of water-saturated soil over impermeable material.

High relief

Areas with significant difference in elevation which impact the likelihood of debris flow.

Frost wedging

The process of rock disintegration caused by freeze-thaw cycles.

Human impact on mass wasting

Construction and other human activities can destabilize slopes.

Viscosity

Resistance to flow in fluids and semi-fluids, affecting mass wasting processes.

Shear force/stress

The force that acts parallel to the slope, influencing stability.

Sediment

Unconsolidated material of any size at the Earth's surface.

Mass wasting classification

Based on factors like type of material, rate of movement, and type of movement.

Debris flow prevention

Retaining walls and vegetation can help prevent mass wasting events.

Absence of vegetation

An area lacking vegetation is more susceptible to mass wasting.

Construction impact

Adding weight to a slope can destabilize it and lead to mass wasting.

Slope failure

Occurs when gravitational forces exceed the strength of materials on a slope.

Bioturbation

The disturbance of soil by living organisms, affecting soil structure.

Gravitational forces

The forces that cause materials to slide down slopes.

Mass wasting disaster

The catastrophic movement of soil, rock, and debris usually triggered by natural events.

Mass wasting factors

Includes slope angle, water content, vegetation, and geological structure.

Vegetated slopes

Less likely to experience mass wasting due to root structure supporting soil.

Frictional resistance

The force that opposes motion between two surfaces in contact.

Earthquake-triggered slides

Movements can be initiated by seismic events disrupting stability.

Rate of movement

A critical factor in defining types of mass wasting, from creep to rapid slides.

Groundwater drainage

Can reduce mass wasting likelihood by lowering pore pressure.

Precipitation effects

Heavy rainfall can increase pore pressure and lead to mass wasting events.

Slope stability

The ability of a slope to resist failure under gravitational forces.

Rockfall

Rapid dislodging of rocks from a slope due to gravity.

Lahar

A volcanic mudflow resulting from heavy rain mixing with volcanic ash.

Shock forces

Forces generated by explosions or impacts that can trigger mass wasting.

Colluvial material

Soil and debris transported by gravity.

Stream undercutting

Occurs when a stream cuts into a slope, destabilizing it.

Sliding mass types

Includes translational, rotational, and debris slides.

Soil composition

Types of minerals and organic matter that influence stability.

Vegetation root systems

Help to anchor soil and reduce erosion and mass wasting.

Mass wasting solutions

Implementing engineering solutions like drainage and grading.

Psychological aspects

Understanding human perception of slope stability and risks involved.

Deceleration pressure

Affects the momentum of sliding materials down a slope.

Critical angle of repose

The steepest angle at which a sloped surface formed of a particular material is stable.