Midterm 1 - Important terms and concepts GEOL-1100: Dynamic Earth

Vocabulary flashcards covering key terms, definitions, and concepts from GEOL-1100 lectures 1–7.

Uniformitarianism

Geologic processes today also shaped Earth in the past.

Atom

Basic unit of matter: protons, neutrons, electrons.

Proton

Positive particle in nucleus; defines element.

Neutron

Neutral particle in nucleus; adds to mass.

Electron

Negative particle orbiting nucleus; controls chemical bonds.

Element

Substance defined by proton count; can't be broken down chemically.

Ion

Atom/molecule with charge (lost or gained electrons).

Anion

Negative ion (gained electrons).

Cation

Positive ion (lost electrons).

Isotope

Same protons, different neutrons (variants of an element).

Nucleosynthesis

Formation of atomic nuclei in stars and early universe.

Big Bang nucleosynthesis

Light element formation in early universe.

Stellar nucleosynthesis

Element formation inside stars via fusion.

Inner planets

Rocky planets: Mercury, Venus, Earth, Mars.

Outer planets

Gas/ice giants: Jupiter, Saturn, Uranus, Neptune.

Orbital eccentricity

How elliptical (non-circular) an orbit is.

Sun composition

Mostly hydrogen and helium (98\%).

Hydrogen

Lightest element; major part of Sun and gas giants.

Helium

Second most abundant in Sun; from hydrogen fusion.

Nuclear fusion in the Sun

Hydrogen to helium conversion, releasing energy.

Proton-proton chain

Dominant fusion reaction in the Sun.

Earth’s composition

Rich in iron, oxygen, silicon.

Planetary differentiation

Earth's materials sorted by density (core, mantle, crust).

Giant-impact hypothesis

Moon formed from Earth-Mars sized body collision.

Tidal force

Gravitational forces that deform bodies, creating tides.

Composition

Types of materials making up a body.

Temperature

Average kinetic energy of particles.

Pressure

Force per unit area by particles.

Volume

Amount of 3D space occupied.

Density

Mass per unit volume; key for Earth's layering.

Depth variation (geology)

How properties (T, P, D, C) change with Earth's depth.

Brittle

Rock fractures readily with little deformation.

Ductile

Rock deforms plastically without breaking.

Lithosphere

Rigid outer shell: crust and upper mantle.

Asthenosphere

Weak, flowing layer beneath lithosphere.

Mesosphere

Lower mantle region (solid).

Outer core

Liquid iron-nickel; generates magnetic field.

Inner core

Solid iron-nickel sphere at Earth's center.

Crust

Outermost solid shell (continental/oceanic).

Mantle

Layer between crust and core.

Core

Earth’s central metallic region.

Continental crust

Thicker, less dense, granitic rocks.

Oceanic crust

Thinner, denser, basaltic rocks.

Density sorting

Materials separate by density during differentiation.

Convection currents (Earth’s mantle)

Mantle movement by heat, drives plate tectonics.

Modern atmosphere composition

Mostly nitrogen (N2), oxygen (O2), argon (Ar).

Ozone (O3)

Trioxygen in stratosphere; absorbs UV.

Greenhouse gases

Gases (CO2, CH4, H2O) that trap heat.

Albedo

Reflectivity of Earth’s surface.

Solar luminosity

Total energy emitted by the Sun.

Earth’s magnetic field

From outer core liquid iron; shields from solar wind.

Biosphere

Zone of life; interacts with atmosphere/geosphere.

Oxygenic photosynthesis

Photosynthesis that releases oxygen.

Cellular respiration

Metabolic process releasing energy from molecules.

Nitrogen fixation

Converting N2 to usable forms (ammonia).

Carbon cycle

Carbon movement: atmosphere, biosphere, oceans, rocks.

Rocks vs minerals

Minerals are crystalline compounds; rocks are mineral aggregates.

Crystal structures

Ordered atom arrangement in a mineral.

Ionic bond

Electrons transferred between atoms.

Covalent bond

Electrons shared between atoms.

Metallic bond

Electrons shared collectively in metals.

Crystal formation

Growth from melt/solution into ordered lattices.

Mineral diagnostic properties

Features to identify minerals (color, luster, hardness, etc.).

Mohs hardness scale

Scale (1-10) for scratch resistance.

Conchoidal fracture

Curved, shell-like fracture (e.g., quartz).

Atomic substitution

One ion replaces another of similar size in a lattice.

Polymorph

Same formula, different crystal structure (e.g., diamond/graphite).

Native element

Mineral of a pure element (e.g., gold).

Mineral classes

Categories by chemistry: Silicates, Oxides, Sulfides, etc.

Silicate minerals

Most abundant crustal minerals (feldspar, quartz).

Silica tetrahedron

SiO_4^{4-} unit; basic silicate building block.

Important silicates

Quartz, Feldspar, Muscovite, Biotite, Amphibole, Pyroxene, Olivine, Garnet, Staurolite, Kaolinite, Chalcedony.

Non-silicate minerals

Minerals without silicate structures.

Major anions (non-silicates)

Key negative groups for mineral classes (O^{2-}, S^{2-}, SO4^{2-}, CO3^{2-}, F^{-}, Cl^{-}, Br^{-}, I^{-}).

Hematite

Iron oxide mineral (Fe2O3).

Pyrite

Iron sulfide (FeS_2); 'fool’s gold.'

Halite

Sodium chloride (NaCl); common halide.

Calcite

Calcium carbonate (CaCO_3); reacts with acid.

Evaporitic minerals

Minerals from water evaporation (sulfates, halides).