Physical Geology

Define geology as the study of earth, and distinguish physical geology from historical geology, outlining their aims and key subdisciplines like ecological geology, bio geoscience, geochemistry, geomorphology, and engineering geology.

Explore the value of geology as the study of the earth, underpinning energy, resources, and materials, waste management, and environmental solutions, while examining earth materials, processes, and history.

Trace the history of geology from ancient Greek thinkers through medieval scholars to modern concepts like uniformitarianism, the rock cycle, fossil succession, and continental drift shaping oil geology.

Discover how the scientific method turns observation into knowledge by asking a question, forming a hypothesis, testing it, modifying as needed, and publishing results that support a theory.

Explore the vast scale of the universe and earth's place in the solar system, the sun's dominance, eight planets, dwarf planets, and other bodies explained by nebular theory.

Discover how the sun, a giant hot plasma, powers the solar system with gravity, fuels life on Earth, and features six layers from core to corona.

Explore the Moon's status as Earth's largest satellite, its mass, gravity, temperature swings, and interior core, plus surface features like maria and highlands, rocks, and the giant impact origin.

Explore terrestrial planets—the four inner worlds Mercury, Venus, Earth, and Mars—sharing earth-like, silica-rich composition and thin atmospheres, with Mercury’s 88-day year, Venus’s thick CO2 atmosphere, and Mars’s wind-eroded surface.

Explore jovian planets—Jupiter, Saturn, Uranus, and Neptune—as giant gaseous worlds with hydrogen–helium atmospheres, layered interiors with rocky cores and hydrogen layers, and ring systems.

Explore small solar system bodies beyond planets and moons, including asteroids in the belt, comets with a coma, meteorites, and dwarf planets.

Explore geological dating to understand earth history through rock records, fossils, and the geological time scale, distinguishing numerical dating from relative dating.

Explore how relative dating orders past events by applying principles such as superposition, original horizontals, lateral continuity, cross-cutting relationships, inclusions, and conformity, including angular and nonconformities.

Numerical dating determines a rock or fossil’s age by measuring radioactive parent-daughter isotopes and half-lives, such as carbon-14, rubidium-87, and uranium systems, with the oldest rock at 4.28 billion years.

Explore fossils, the remains of past life, and how paleontologists study them through processes like permineralization, molds and casts, carbonization and impressions, amber, and trace fossils.

Explore Earth's internal structure by detailing crust, mantle, and core layers, including continental and oceanic crust, the Moho boundary, and the liquid outer core with a solid inner core.

Explore the evolution of continental drift, from fixed continents to Wagener’s hypothesis, supported by identical fossils across distant continents, matching mountain belts, and paleoclimate clues that point to Pangaea.

Explore modern evidence for plate motion, including seafloor spreading at mid-ocean ridges, crustal age patterns, and magnetic polarity stripes, plus hotspots and bathymetric mapping.

Explore how Earth's major plates, including the North American, South American, Pacific, African, Eurasian, Indian, and Antarctic plates, drive continental drift through convergent, divergent, and transform boundaries.

Explain how mantle convection and slab pull drive plate tectonics, with ridge push contributing gravity-driven motion, causing oceanic crust to sink and new crust to form at boundaries.

Examine continental margins as transition zones between continental and oceanic crust, comparing passive margins with active margins, and noting shelf, slope, rise, trenches, and their fisheries and minerals.

Explore ocean floor features including deep ocean trenches, abyssal plains, seamounts (including flat-topped forms), oceanic plateaus, and mid-ocean ridges with their associated valleys.

Explore the four layers of the oceanic crust—water, sediments, basaltic pillow lavas, the sheeted dike complex, and gabbro—and how basaltic melt rises through cracks to form them.

Explore the destruction of oceanic crust at subduction zones, comparing spontaneous marina-type subduction with deep trenches to for subduction, where young crust subducts at shallow angles.

Explore subduction zones, where oceanic plates dive beneath others, forming continental and oceanic volcanic arcs, deep ocean trenches, forearc and back-arc regions, and earthquakes.

Explore how mountains form through collision of crustal bodies, including cordillera-type and alpine-type belts, and through fault-block, tension-driven uplift. Examples include the Himalayas, Alps, Appalachians, and basin-and-range landscapes.

Investigate how isostasy and mantle convection shape the earth's topography, and learn to interpret topographic maps with contour lines reflecting elevation and slope.

Explore weathering—the physical breakdown and chemical alteration of surface rocks from environmental interaction, with mechanical and chemical weathering, and its role in releasing minerals to support plants.

Explore the processes of mechanical weathering that break rocks into smaller pieces, including frost wedging, unloading, thermal expansion, salt crystal growth, biological activity, and abrasion.

Explore chemical weathering, where rocks break down through solution, oxidation, and hydrolysis, and distinguish dissolution by water from hydrolysis with rust and acid interactions.

Explain how corners weather faster because they are attacked in three directions, edges in two, and faces in one, driving spheroidal weathering that turns rocks into sphere-like forms.

Explore soil as the life-supporting interface among biosphere, hydrosphere, and atmosphere, formed by weathering rocks, including clay, sandy, and silt types, with horizons O, A, E, B, and C.

Learn how deserts are dry lands where precipitation wanes below evaporation, and explore arid and semi-arid regions and desert types like subtropical, rainshadow, coastal, continental interior, polar, and extraterrestrial.

Explore wind erosion in arid landscapes, where deflation lifts silt and sand, forming blowouts and desert pavement, and sculpting rocks into ventifacts and yardangs.

Explore how wind transports sediment as bed load and suspended load, via saltation and creeping on the desert floor, and how dust storms form.

Explore how wind deposits shape arid landscapes by eroding, transporting, and depositing sand and silt, forming dunes and other landforms.

Explore atoms as the building blocks of matter, with a nucleus of protons and neutrons and orbiting electrons, and understand atomic number, isotopes, and the periodic table.

Learn how atoms bond by transferring or sharing valence electrons to form a stable octet. Explore ionic, covalent, and metallic bonds, with examples like carbon dioxide.

Define minerals as naturally occurring inorganic solids with an orderly crystal structure and definite chemical composition.

Explore mineral formation through precipitation, crystallisation, and deposition, driven by temperature drops, ions in solution, water loss, and magma cooling, with reef-building biological activity.

Identify minerals by applying physical properties such as luster, streak, translucency, color, crystal habit, hardness, and density, and use taste, look, and feel as practical identification tools.

Explore sedimentary rocks formed by deposition on Earth through erosion and weathering. Identify clastic, chemical, and organic types, with coal as an organic example and their mineral resources and history.

Examine how weathered fragments transport and deposit to form detrital sedimentary rocks, composed of clasts, matrix, and cement, and distinguish gravel, sand, and mud by grain size.

Explore how grain size, sorting, and grain shape reveal past depositional environments and energy conditions, with angular grains near the source and rounded grains far away.

Discover coal as the second source of primary energy, powering 40% of global electricity and 30% of world energy. Learn how plant material in swamps becomes lignite, bituminous, and anthracite.

Sediments transform into sedimentary rocks through diagenesis in the upper crust under heat and pressure, with lithification—cementation by calcite, silica, or iron oxide—and compaction that reduces porosity.

Identify how sedimentary structures form during deposition and lithification, from strata and bedding planes to cross-beds, graded beds, ripple marks, and mud cracks.