GEO 101 Exam 1 Study Guide Vocabulary

A set of vocabulary flashcards covering key geological concepts, Earth formation, plate tectonics, and mineralogy based on the GEO 101 Exam 1 Study Guide.

Science

A systematic field of study aimed at understanding the natural world through observation, experimentation, and evidence.

Geology

The scientific study of the Earth, its materials, structures, processes, history, and the forces that shape it over time.

Hypothesis

A proposed, testable explanation for an observation or phenomenon that can be supported or refuted through scientific investigation.

Theory

A well-substantiated, comprehensive explanation of a natural phenomenon supported by a vast body of evidence and extensive testing.

Big Bang Theory

The prevailing cosmological model explaining the origin and expansion of the universe from a singular high-density, high-temperature state.

Terrestrial Planets

Inner, rocky planets characterized by solid, metallic and silicate compositions, including Mercury, Venus, Earth, and Mars.

Ice/Gas Giants

Outer planets composed primarily of hydrogen, helium, water, ammonia, and methane gases and icy materials, including Jupiter, Saturn, Uranus, and Neptune.

Biosphere

The global ecological system integrating all living beings and their relationships across Earth's surface, atmosphere, and hydrosphere.

Lithosphere

The rigid, brittle outer layer of Earth comprising the crust and uppermost solid mantle, broken into tectonic plates.

Hydrosphere

All the water on or near Earth's surface, including oceans, lakes, rivers, glaciers, groundwater, and water vapor.

Atmosphere

The gaseous envelope surrounding Earth, retained by gravity, that forms weather patterns and protective layers.

Asthenosphere

The weak, ductile, and partially molten layer of the upper mantle directly beneath the lithosphere that allows tectonic plate movement.

Continental Crust

The thicker, lower-density, primarily felsic (granitic) portion of Earth's crust that forms the landmasses and continental shelves.

Oceanic Crust

The thinner, higher-density, primarily mafic (basaltic) portion of Earth's crust underlying ocean basins.

Plate Tectonics

The unifying geological theory stating that Earth's outer shell is divided into several rigid plates that move across the asthenosphere.

Continental Drift

The early 20th-century hypothesis proposed by Alfred Wegener stating that Earth's continents were once connected and slowly drifted apart.

Convection

The transfer of thermal energy through fluid motion driven by density differences, serving as a primary driver of Earth's mantle circulation.

Ridge Push

A tectonic driving force where elevated ocean ridges create a gravitational pull pushing young, hot oceanic lithosphere away from the ridge crest.

Slab Pull

A primary tectonic driving force resulting from cold, dense subducting oceanic lithosphere sinking into the mantle under gravity.

Paleomagnetism

The study of the record of Earth's historic magnetic field preserved in magnetic minerals within rocks over geological time.

Seafloor Spreading

The process occurring at ocean ridges where new oceanic crust forms through volcanic activity and gradually moves away from the ridge axis.

Divergent Margins

Tectonic plate boundaries where two plates pull apart from each other, leading to seafloor spreading or continental rifting.

Convergent Margins

Tectonic plate boundaries where two plates move toward each other, resulting in subduction or continental collision.

Atolls

Ring-shaped coral reefs, islands, or series of islets surrounding a central body of water called a lagoon, typically formed around submerged volcanic islands.

Hotspot

An area in Earth's mantle where thermal plumes of hot material rise to generate persistent volcanism independent of tectonic plate boundaries.

Polymorph

Minerals that possess the exact same chemical composition but exhibit different crystalline structures and physical properties.

Mineral

A naturally occurring, inorganic solid with a definite chemical composition and an ordered internal crystalline structure.

Rock

A naturally occurring solid aggregate composed of one or more minerals or mineraloids.

Felsic Minerals

Silicate minerals enriched in lighter elements like silicon, oxygen, aluminum, potassium, and sodium, typically lighter in color and less dense.

Mafic Minerals

Silicate minerals enriched in heavier elements like iron and magnesium, typically darker in color and denser.

Silicates

The most abundant group of rock-forming minerals on Earth, characterized by a fundamental framework of silicon-oxygen tetrahedra.

Crystal Habit

The characteristic external shape or growth appearance of an individual crystal or aggregate of crystals.

Cleavage

The tendency of a mineral to break along specific flat planes of structural weakness within its crystalline lattice.

Streak

The color of a mineral in its finely powdered form, observed by rubbing the mineral across an unglazed porcelain plate.