Earth Science Compressed Study Guide

Comprehensive set of vocabulary flashcards derived from the Earth Science study guide, covering key concepts in mineralogy, petrology, geology, plate tectonics, volcanology, soil science, scientific foundations, and basic chemistry.

Mineral

A naturally occurring, inorganic solid with a definite chemical composition and a crystal structure.

Rock

A natural solid made of one or more minerals or mineral-like materials.

Luster

How light reflects off the surface of a mineral.

Cleavage

The property of a mineral breaking along flat or smooth planes.

Fracture

The property of a mineral breaking irregularly.

Streak

The color of a mineral's powder.

Hardness

A mineral's resistance to scratching.

Mohs Scale

A relative scale ranking mineral hardness from $1$ (Talc) to $10$ (Diamond).

Quartz

A mineral composed of $SiO_2$ with a hardness of $7$ that has no cleavage and exhibits fracture.

Calcite

A mineral composed of $CaCO_3$ with a hardness of $3$ that exhibits cleavage, fizzes with dilute HCl, and displays double refraction.

Double Refraction

An optical property where light splits into $2$ paths, causing an object viewed through the mineral to appear doubled.

Mica

A sheet-like mineral with excellent cleavage that splits into thin sheets, including muscovite and biotite.

Weathering

The process that breaks rock down into smaller pieces.

Erosion

The process that moves sediment from one location to another.

Igneous Rock

Rock formed from the cooling and crystallization of magma or lava.

Phaneritic Texture

An igneous rock texture featuring large crystals formed from slow cooling, usually intrusive like granite.

Aphanitic Texture

An igneous rock texture featuring small crystals formed from faster cooling, usually extrusive.

Glassy Texture

An igneous rock texture with no visible crystals formed from extremely fast cooling, like obsidian.

Porphyritic Texture

An igneous rock texture featuring both large and small crystals resulting from two different cooling rates.

Quenching

Extremely rapid cooling of magma or lava that can create a glassy texture.

Dike

An intrusive igneous body that cuts across existing rock layers.

Sill

An intrusive igneous body that goes between existing rock layers.

Batholith

A very large intrusive igneous body formed deep underground.

Laccolith

A dome-shaped igneous intrusion that pushes overlying rock layers upward.

Magma Chamber

An underground magma storage body.

Granite

An intrusive igneous rock characterized by a phaneritic texture, large crystals, and slow cooling.

Obsidian

An extrusive igneous rock characterized by a glassy texture formed by very fast cooling.

Clastic Sedimentary Rock

Sedimentary rock made of weathered pieces of older rocks, such as sandstone, shale, and conglomerate.

Chemical/Biochemical Sedimentary Rock

Sedimentary rock formed when minerals precipitate from water and/or biological activity, such as some limestone.

Compaction

The sedimentary process of squeezing sediment together under pressure.

Cementation

The sedimentary process where minerals glue sediment particles together.

Lithification

The process of turning sediment into solid rock through compaction and cementation.

Metamorphic Rock

Rock created when existing rock is changed by heat, pressure, and fluids without melting completely.

Foliation

A layered or aligned appearance in metamorphic rock caused by differential stress aligning minerals.

Asthenosphere

The weak, ductile upper mantle layer that slowly flows and allows tectonic plates to move over it.

Outer Core

Earth's liquid layer composed of iron and nickel whose movement creates Earth's magnetic field.

Inner Core

Earth's solid innermost layer made mostly of iron and nickel, kept solid by extreme pressure.

Divergent Boundary

A tectonic boundary where plates move apart under tension stress, creating mid-ocean ridges, rift valleys, and new crust.

Convergent Boundary

A tectonic boundary where plates move together under compression stress, causing subduction, volcanoes, earthquakes, and trenches.

Transform Boundary

A tectonic boundary where plates slide past each other under shearing stress, primarily causing earthquakes.

Subduction

The process where one tectonic plate sinks beneath another.

Alfred Wegener

The scientist who proposed the hypothesis of continental drift using evidence like continental fit, matching fossils, and climate data.

Seafloor Spreading

The process where new oceanic crust forms at mid-ocean ridges and moves outward.

Harry Hess

The scientist associated with the theory of seafloor spreading.

Magma

Molten rock located underground.

Lava

Molten rock at Earth's surface.

Volatiles

Dissolved gases in magma or lava, such as water vapor and $CO_2$.

Viscosity

A fluid's resistance to flow.

Shield Volcano

The largest and broadest type of volcano with gentle slopes formed by low-viscosity lava.

Stratovolcano

A tall and steep volcano made of layers of lava and volcanic material, common at subduction zones.

Cinder Cone

A smaller, steep volcano constructed mainly of volcanic fragments.

Hotspot

A mantle plume of hot material rising from deep mantle to generate magma, creating a chain of volcanoes as a plate moves over it.

Flux Melting

Melting caused by adding volatiles to mantle rock, lowering its melting temperature.

Blocky Lava

Viscous lava flow characterized by a rough, broken, or blocky surface.

Pahoehoe

Lava flow characterized by a smooth or ropy surface.

Aa

Lava flow characterized by a rough, jagged surface.

Mechanical Weathering

The breakdown of rock into smaller pieces without changing its chemical composition.

Frost Wedging

Mechanical weathering process where water enters cracks, freezes, expands, and breaks rock.

Root Wedging

Mechanical weathering process where plant roots grow into cracks and exert pressure to break rock.

Humus

Partially decomposed organic material found in soil.

Soil Triangle

A chart used to determine soil classification based on percentages of sand, silt, and clay.

Uniformitarianism

The principle stating that the same natural processes operating today also operated in the past ('the present is the key to the past').

Catastrophism

The concept that Earth is primarily shaped by sudden, major events like volcanic eruptions, earthquakes, or asteroid impacts.

Objective Observation

A measurement or observation made without personal opinion.

Numerical Data

Data represented using numbers (e.g., $25^\circ\text{C}$, $40\%$).

Pseudoscience

Claims presented as scientific that lack reliable scientific evidence or methods.

Geosphere

The solid portion of Earth, including rocks, minerals, and soil.

Hydrosphere

All liquid and frozen water on Earth, including oceans, rivers, lakes, and groundwater.

Atmosphere

The gases surrounding Earth.

Biosphere

All living organisms on Earth.

Proton

A positively charged subatomic particle located in the nucleus of an atom.

Neutron

A neutral subatomic particle ($0$ charge) located in the nucleus of an atom.

Electron

A negatively charged subatomic particle located outside the nucleus of an atom.

Cation

A positively charged ion formed when an atom loses electrons.

Cohesion

The property of water molecules sticking to other water molecules.

Adhesion

The property of water molecules sticking to other non-water substances.