Order events without exact dates.
Superposition, cross-cutting relations and inclusions establish sequence.
Side 107
Geology
A study of Earth through materials, structures and time. Geology reconstructs processes that are often too slow, deep or large to observe directly by reading rocks, landscapes, fossils and geophysical signals.
material→process→record→time→reconstruction
06study lenses
36working concepts
V0working model
107Side
Geology extends causal reasoning across immense timescales.
Present structures are snapshots of processes that can accumulate for millions of years.
Estimate numerical ages.
Radiometric systems convert predictable isotope decay into time constraints.
Missing rock is part of the record.
Erosion or non-deposition can remove intervals that must be inferred.
Processes run at different speeds.
Catastrophic events and gradual background change both shape the record.
Match layers across space.
Fossils, chemistry and datable horizons connect separated sections.
A process can change character with scale.
A river event, basin history and mountain belt occupy different temporal frames.
Rocks preserve the conditions under which they formed and changed.
The rock cycle links melting, crystallization, weathering, burial and metamorphism.
Solidified melt.
Texture and composition reveal cooling history and magma source.
Deposited particles or precipitates.
Layering, grain size and structures record transport and environment.
Rock transformed without fully melting.
Mineral assemblages constrain pressure, temperature and fluid history.
Crystal structure controls properties.
Hardness, cleavage and chemistry make minerals diagnostic components.
Rock breaks down at the surface.
Physical and chemical weathering feed sediment and soils.
Sediment changes after deposition.
Compaction, cementation and fluids alter the original record.
Plate tectonics organizes much of large-scale geology.
Moving lithospheric plates explain recurring patterns in earthquakes, volcanoes, mountains and ocean basins.
Plates move apart.
Rifting and seafloor spreading create new crust.
Plates collide.
Subduction recycles lithosphere; continental collision thickens crust.
Plates slide laterally.
Strain accumulates and releases along major faults.
Heat drives slow convection.
Plate motion couples surface lithosphere to deeper Earth dynamics.
Crust floats gravitationally on denser mantle.
Loading and unloading produce vertical adjustment.
Mountains record deformation.
Folding, faulting, metamorphism and erosion interact during mountain building.
Landscapes are active systems rather than static scenery.
Water, ice, wind, gravity and life move material downhill and downstream.
Flow erodes, transports and deposits.
Channel form responds to discharge, sediment and slope.
Ice reshapes terrain.
Erosion and deposition leave diagnostic valleys, moraines and sediments.
Waves and currents redistribute sediment.
Shorelines migrate as energy, sediment supply and sea level change.
Gravity drives mass movement.
Failure depends on material strength, water pressure and geometry.
Weathering meets biology.
Soil profiles record parent material, climate, organisms, relief and time.
Soluble rocks create underground drainage.
Caves and sinkholes emerge where dissolution reorganizes flow.
Geology reconstructs invisible history from partial traces.
Interpretation works by combining independent proxies with physical constraints.
Layers preserve sequence.
Facies changes separate time from changing environments.
Life helps date and interpret rocks.
Assemblages constrain age, habitat and past ecology.
Elements and isotopes act as proxies.
Chemical signatures can record temperature, source and fluid interaction.
Measure properties beneath the surface.
Seismic waves, gravity and magnetism reveal hidden structure.
Spatial relationships encode history.
Contacts, folds and faults turn field observations into geometric hypotheses.
Drilling samples inaccessible sequences.
Cores preserve vertical records with direct material evidence.
Geologic hazards combine physical processes with human exposure.
Risk rises when hazardous processes intersect vulnerable people and infrastructure.
Fault rupture releases stored strain.
Magnitude, distance, depth and local ground conditions shape shaking.
Magma, gas and water create multiple hazards.
Lava is only one threat; ash, flows and lahars can dominate impacts.
Slopes fail when driving stress exceeds resistance.
Rain, earthquakes, excavation and erosion can trigger failure.
Rapid displacement generates long waves.
Coastal geometry can amplify inundation far from the source.
Ground surface lowers.
Extraction, dissolution, compaction and tectonics can each produce sinking.
Hazard is not disaster by itself.
Land use, construction, warning and preparedness determine consequence.