GeologyQ&A by dot point

The three classes of rock (igneous, sedimentary and metamorphic), how each forms, and the textural and mineralogical features used to recognise each class in hand specimen.

The definition of a mineral, and the diagnostic physical properties (hardness, cleavage, fracture, lustre, colour, streak, density and crystal habit) used to identify common rock-forming minerals in hand specimen.

The abundance of elements in the crust, the silicon-oxygen tetrahedron as the building block of the silicate minerals, and how the degree of tetrahedral linkage (isolated, chain, sheet and framework) controls cleavage, hardness and density.

The rock cycle as the set of processes (weathering, erosion, transport, deposition, burial, lithification, metamorphism, melting and crystallisation) that recycle material between the three rock classes, driven by internal heat and surface energy.

The sources of the Earth's internal heat, the geothermal gradient and heat flow, and how heat drives mantle convection, melting and metamorphism as the internal limb of the rock cycle.

Deposition in different environments, the formation of sedimentary structures (bedding, cross-bedding, graded bedding, ripple marks) and how these are used as way-up indicators and palaeoenvironment evidence.

The mechanisms of physical and chemical weathering, the distinction between weathering, erosion and transport, and how transport agents round and sort sediment to record transport history.

The conditions and modes of fossil preservation, the principle of faunal succession, and the use of zone (index) fossils to correlate and relatively date strata.

The principle of radiometric dating using radioactive decay and half-life, the parent-to-daughter ratio, the choice of isotope system, and the assumptions and limitations of the method.

The principles of relative dating (superposition, original horizontality, cross-cutting relationships, included fragments and unconformities) and how they are combined to establish the sequence of geological events.

The structure of the geological timescale (eons, eras, periods and epochs), how it is built from relative and absolute dating, and the major events that define its main boundaries.

The compositional and mechanical layering of the Earth (crust, mantle, outer and inner core; lithosphere and asthenosphere) and the seismic evidence (P and S wave behaviour, shadow zones, discontinuities) used to deduce it.

The three types of plate boundary (constructive, destructive and conservative), the processes and features at each, and the driving forces of plate motion (mantle convection, ridge push and slab pull).

The development of plate tectonic theory from continental drift, and the evidence for it (continental fit, matching geology and fossils, palaeoclimate, sea-floor spreading and palaeomagnetic stripes).

Geological evolution of Britain (option T4): the main tectonic events and orogenies (Caledonian, Variscan, Alpine), the changing palaeogeography and palaeolatitude of Britain through the Phanerozoic, and the rocks and structures these events produced.

Geology of the lithosphere (option T5): the lithosphere and asthenosphere, the structure and formation of oceanic and continental crust, the geophysical evidence for the Earth's interior (seismic, gravity, magnetic, heat flow), and the processes of isostasy and crustal recycling.

Quaternary geology (option T3): the evidence for glacial and interglacial cycles, glacial and periglacial processes and deposits, the dating of Quaternary events, and the causes of Quaternary climate change including Milankovitch cycles.

The causes of earthquakes (elastic rebound, focus and epicentre), seismic waves (P, S and surface waves), the measurement of size (magnitude and intensity), the primary and secondary hazards (ground shaking, liquefaction, landslides, tsunami), and the prediction and mitigation of seismic risk.

The types of mass movement (rockfall, slide, slump, flow), the factors that control slope stability (slope angle, rock type and structure, water, vegetation, undercutting), the ground hazards of subsidence and collapse (mining, dissolution), and the prediction and prevention of these hazards.

The control of magma composition and gas content on eruptive style, the volcanic hazards (lava flows, pyroclastic flows, ash falls, lahars, gases, sector collapse), the monitoring of volcanoes (seismicity, ground deformation, gas, thermal), and the prediction and management of volcanic risk.

The construction of a geological cross-section from a map, the projection of dipping beds, folds, faults and unconformities into the section, and the reconstruction of the full sequence of geological events of an area from the map and section.

The interpretation of geological maps: reading dip and strike from outcrop patterns, the rule of Vs for outcrops crossing valleys, recognising horizontal, dipping, folded and faulted strata and unconformities, and using the pattern to deduce the underlying structure.

Partial melting of the mantle and crust, the controls on melting (temperature, pressure and water), magma series, and the evolution of magma by fractional crystallisation interpreted through Bowen's reaction series.

The control of cooling rate on crystal size and texture (glassy, fine, coarse, porphyritic), and the recognition of intrusive forms (dykes, sills, batholiths, laccoliths) and extrusive forms (lava flows, pyroclastic deposits) with their contact relationships.

Contact, regional and dynamic metamorphism, the controls of temperature, pressure and fluids, the increase of grade and the use of index minerals and metamorphic facies, and the textures (slate, schist, gneiss, hornfels, marble, quartzite) they produce.

The formation of clastic, biogenic and chemical sedimentary rocks, the processes of diagenesis (compaction, cementation, recrystallisation), and the use of sedimentary structures, including those formed by infrequent processes such as turbidity currents, as evidence of conditions.

The classification of faults (normal, reverse, thrust, strike-slip) by the relative movement of the hanging wall and footwall and by the stress regime, the terminology of fault planes (dip, throw, heave, slickensides), and the recognition of faults in the field and on maps.

The geometry of folds (limbs, axial plane, hinge, fold axis, interlimb angle), the classification of folds (anticline, syncline, symmetrical, asymmetrical, overturned, recumbent, isoclinal) and the use of fold style to interpret the direction and intensity of compression.

The concepts of stress and strain, the difference between compressional, tensional and shear stress, elastic, brittle and ductile behaviour, and the factors (temperature, confining pressure, strain rate, rock type and fluids) that control how a rock deforms.

The types of unconformity (angular, disconformity, nonconformity) and their significance, the structures of mountain belts (nappes, thrust stacks), and the use of cross-cutting relationships and superposition to reconstruct the sequence of tectonic events.

The evidence for organic evolution from the fossil record (morphological change through time, transitional forms), the major patterns of the history of life, and the causes and consequences of mass extinctions, including the end-Permian and end-Cretaceous events.

The use of lithological and palaeontological proxies (evaporites, coals, tillites, coral reefs, fossil assemblages) and isotopic and geochemical methods to reconstruct past climates, and the role of palaeoclimate evidence in confirming continental movement.

The use of functional morphology to interpret the mode of life of fossil organisms (feeding, locomotion, environment), the concept of trace fossils and their value, and the use of fossil assemblages and adaptations to reconstruct past environments.

The formation of coal and its rank, the geological basis of energy resources (fossil fuels, geothermal, nuclear fuels) and bulk materials, the distinction between renewable and non-renewable resources, and the environmental impacts and sustainable management of extraction, including carbon capture and storage.

The formation of hydrocarbons from organic-rich source rocks, the requirements of a petroleum system (source, reservoir, cap rock, trap, maturation and migration), the main trap types (anticlinal, fault, stratigraphic, salt dome), and the principles of exploration and recovery.

The processes that concentrate metals into ore deposits (magmatic segregation, hydrothermal veins, secondary enrichment, placer and sedimentary processes), the meaning of grade, cut-off grade and reserves, and the principles of evaluating and exploiting a mineral deposit.

The storage and movement of groundwater in aquifers (porosity, permeability, water table, artesian conditions), the abstraction and sustainable use of groundwater, and the influence of rock and ground conditions on engineering works such as dams, tunnels and foundations.

The practical endorsement: the specified practical activities and core techniques, the minimum fieldwork requirement, the Common Practical Assessment Criteria (CPAC), and how practical skills are assessed both by the separate endorsement and within the written components.