WJEC Eduqas GCE A LEVEL Geology Flashcards

This set of 500 vocabulary flashcards covers the complete WJEC Eduqas GCE A Level Geology specification, including terms from Fundamentals of Geology, Interpreting the Geological Record, Geological Themes, and technical mathematical and scientific skill requirements.

WJEC Eduqas GCE A LEVEL Geology

An A level qualification providing comprehensive coverage of Earth studies, including structures, evolution, and dynamics, starting for award from 2019.

Component 1

Geological Investigations: A 2 hour 15 minute written examination accounting for $35\%$ of the qualification.

Component 2

Geological Principles and Processes: A 1 hour 45 minute written examination accounting for $30\%$ of the qualification.

Component 3

Geological Applications: A 2 hour written examination accounting for $35\%$ of the qualification.

Practical Endorsement

A non-exam assessment of practical competency reported separately and not contributing to the final grade.

Ofqual Qualification Number

$$603/0859/X$$

Qualifications Wales Designation Number

$$C00/1174/5$$

Lithophile

Part of the Goldschmidt system classifying Earth's elements that associate with the silicate crust.

Siderophile

Part of the Goldschmidt system classifying Earth's elements that associate with the metallic core (iron-loving).

Chalcophile

Part of the Goldschmidt system classifying Earth's elements that associate with sulfur.

Atmophile

Part of the Goldschmidt system classifying Earth's elements that exist as gas and are found in the atmosphere.

Chondrites

Undifferentiated meteorites whose bulk composition is comparable to that of the Earth.

Commonest rock-forming minerals

Silicates, which are built from silicon-oxygen tetrahedra.

Silicon-oxygen tetrahedra structures

Includes single, chain, sheet, and framework silicates.

Mineral

A naturally occurring inorganic chemical compound or element with a composition expressed as a chemical formula.

Rock

An aggregate composed of minerals, pre-existing rocks, or fossils.

Primary crustal elements

The eight main elements comprising the Earth's crust: O, Si, Al, Fe, Ca, Na, K, and Mg.

Crystalline texture

A rock texture characterized by interlocking crystals, typically indicating an igneous or metamorphic origin.

Clastic texture

A rock texture composed of fragments (clasts) of pre-existing minerals and rocks, typical of sedimentary rocks.

Magnification Formula

$$\text{magnification} = \frac{\text{size of image}}{\text{size of real object}}$$

Physical weathering

The breakdown of rock into smaller fragments by processes like insolation and freeze/thaw cycle.

Chemical weathering

The alteration of silicate and carbonate rocks through hydrolysis, carbonation, solution, and oxidation.

Biological weathering

Weathering involving physical and chemical changes caused by living organisms.

Traction

A mode of transport where large particles are rolled or slid along a bed by a flow.

Saltation

A mode of transport where particles are bounced along a bed.

Suspension

A mode of transport where fine particles are carried within the body of the flow.

Solution

A mode of transport where minerals are dissolved in water.

Flocculation

A process in sedimentary environments where individual clay particles stick together to form larger clusters or flocs.

Precipitation

The process by which solid material settles out of a liquid solution, forming sedimentary rocks like evaporites.

Sorting

The distribution of grain size in a sediment or sedimentary rock, reflecting the energy and duration of transport.

Graphic log

A visual representation of an unfamiliar geological sequence using a vertical scale and specific symbols.

Diagenesis

The physical and chemical changes occurring in sediments after deposition and during their conversion to rock.

Lithification

The process of turning sediment into rock through compaction, recrystallisation, cementation, and pressure solution.

Porosity

The volume of void spaces in a rock or sediment.

Permeability

The ability of a rock or sediment to allow fluids to pass through it.

Immature sedimentary rock

A rock characterized by a wide range of mineral compositions and/or lithic clasts.

Mature sedimentary rock

A rock with restricted mineralogies dominated by species resistant to weathering and erosion, like quartz.

Radiogenic heat

Heat produced within the Earth by the decay of radioactive isotopes.

Primordial heat

Residual heat from the Earth's formation.

Conduction

Heat transfer through solid rock without the movement of the material itself.

Convection

Heat transfer through the mantle via the movement of hot, less dense material rising and cooler, denser material sinking.

Geothermal gradient

The rate of increase in temperature with depth in the Earth's interior.

Pluton

A large body of intrusive igneous rock formed when magma cools deep underground.

Dyke

A sheet-like igneous intrusion that cuts across the bedding or foliation of the host rock (discordant).

Sill

A sheet-like igneous intrusion that is parallel to the bedding or foliation of the host rock (concordant).

Euhedral

An igneous crystal shape showing well-formed and distinct faces.

Subhedral

An igneous crystal shape with partially formed faces.

Anhedral

An igneous crystal shape lacking well-formed faces.

Equicrystalline

A texture where all crystals in an igneous rock are of approximately the same size.

Porphyritic

A texture containing large crystals (phenocrysts) set in a finer-grained groundmass.

Vesicular

A texture characterized by small holes (vesicles) formed by gas bubbles trapped in cooling lava.

Tuff

A rock formed from fragmental volcanic material (pyroclastic) ejected during an eruption.

Pillow structure

A rounded, sack-like structure formed when lava is extruded underwater.

Aa

A type of basaltic lava flow with a rough, blocky, and jagged surface.

Pahoehoe

A type of basaltic lava flow with a smooth, billowy, or ropy surface.

Columnar joints

Regularly spaced vertical cracks that form as a lava flow cools and contracts.

Partial melting

The process where only a portion of a solid is melted, often occurring at divergent boundaries to create basaltic magma.

Divergent plate margin

A tectonic boundary where two plates move away from each other, often leading to decompression melting of mantle rocks.

Convergent plate margin

A tectonic boundary where plates move toward each other, leading to subduction and andesitic magma generation.

Mantle plume

A localized column of hot mantle rock that rises toward the surface, generating basaltic magma in hotspots.

Nuées ardentes

Incandescent, fast-moving clouds of hot gas and volcanic ash (pyroclastic flows).

Lahar

A volcanic mudflow or debris flow consisting of a slurry of pyroclastic material and water.

Metamorphism

The mineralogical or textural change of rocks in response to changes in temperature and/or pressure without melting.

Contact metamorphism

Thermal metamorphism occurring near igneous intrusions, producing non-foliated rocks.

Regional metamorphism

Metamorphism occurring over large areas associated with mountain building and high pressure/temperature.

Foliation

A planar arrangement of mineral grains or structural features in a metamorphic rock (e.g., slaty cleavage, schistosity).

Hooke's Law

A physical principle relating stress and strain, identifying elastic, brittle, and plastic behavior in rocks.

Yield strength

The stress level at which a rock begins to deform plastically.

Dip

The maximum angle of inclination of a planar feature (like a bedding plane) from the horizontal.

Strike

The direction of a horizontal line on the surface of a dipping planar feature.

Limb

The side of a geological fold.

Hinge

The line of maximum curvature in a fold.

Axial plane trace

The line formed by the intersection of the axial plane with a surface.

Anticline

A fold that is convex upward, usually with the oldest rocks in the core.

Syncline

A fold that is concave upward, usually with the youngest rocks in the core.

Normal fault

A dip-slip fault where the hanging wall moves down relative to the footwall, caused by tension.

Reverse fault

A dip-slip fault where the hanging wall moves up relative to the footwall, caused by compression.

Strike-slip fault

A fault where the movement is predominantly horizontal, classified as sinistral (left) or dextral (right).

Unconformity

A hiatus or gap in the geological record representing a period of erosion or non-deposition.

Uniformitarianism

The geological principle that the present is the key to the past.

Facies

The total characteristics of a rock unit reflecting its depositional environment (lithofacies and biofacies).

Brachiopod

A marine invertebrate with two unequal valves (pedicle and brachial) and bilateral symmetry across the valves.

Bivalve

A marine or freshwater mollusc with two equal valves and bilateral symmetry between the valves.

Pedicle valve

The larger valve of a brachiopod, often containing the foramen.

Foramen

An opening in a brachiopod shell through which the pedicle (a fleshy stalk) protrudes.

Umbones

The beak-like projections at the top of a bivalve or brachiopod valve.

Pallial line

A mark on the interior of a bivalve shell showing where the mantle was attached.

Pallial sinus

An indentation in the pallial line of a bivalve, indicating the presence of retractable siphons.

Cephalopod suture line

The line formed by the junction of a chamber wall (septum) and the outer shell wall in cephalopods.

Glabella

The central, raised part of a trilobite's cephalon (head).

Thorax

The segmented midsection of a trilobite's body.

Pygidium

The tail piece of a trilobite.

Graptolite

Extinct colonial marine organisms with proteinaceous skeletons consisting of stipes and thecae.

Thecae

The small cups or tubes that housed individuals in a graptolite colony.

Trace fossil

Evidence of an organism's activity rather than its body, such as burrows, tracks, or coprolites.

Coprolite

Fossilized animal droppings/excrement.

Life assemblage

Fossils preserved in their original living position without transportation.

Death assemblage

Fossils preserved after they have been transported away from their living environment.

Derived fossil

A fossil eroded from older rocks and re-deposited in a younger sediment.

Zone fossil

A fossil used for relative dating and correlation that is widely distributed, easily identified, and evolved rapidly.