Natural Sciences
Earth & Space Sciences
Geology
ElementScope CategorySub-ItemDefinitionEconomic & Applied Geology
1. Domain1.1 Scope of the DomainBoundariesThe range of phenomena the science includes and excludes.Studies the formation, distribution, exploration, evaluation, and extraction of Earth materials with economic value (metals, industrial minerals, hydrocarbons, groundwater, construction materials). Includes ore-deposit science, mineral exploration, petroleum geology, geothermal systems, engineering geology, and resource assessment. Excludes purely academic geology unless it directly informs resource discovery or extraction.
ScaleThe spatial, temporal, or organizational level at which the science operates (e.g., quantum, cellular, social, cosmic).Operates from atomic/mineral scale (trace element substitution) → rock/orebody scale (veins, stratiform deposits) → basin scale (petroleum systems) → regional/continental mineral belts → global resource distribution and market-scale assessments. Timescales range from seconds (drilling responses) to billions of years (crustal metallogenic evolution).
1.2 Ontological CommitmentsEntitiesThe kinds of things assumed to exist within the domain (particles, organisms, agents, fields, etc.).Orebodies, mineral grains, hydrothermal fluids, magmatic systems, sedimentary basins, traps/seals, reservoirs, source rocks, structural traps, alteration halos, faults, fractures, aquifers, geothermal reservoirs, drilling infrastructure.
PropertiesThe fundamental attributes these entities possess (mass, charge, genotype, preference, etc.).Grade, tonnage, concentration, permeability, porosity, fracture density, reservoir quality, thermal gradient, alteration style, mineral associations, metal tenor, ore textures, fluid composition, pressure, temperature.
CategoriesThe basic ontological types used to classify domain elements (substances, processes, relations, structures).Ore-deposit types (porphyry, VMS, SEDEX, epithermal, skarn, orogenic gold, IOCG), petroleum system elements (source, reservoir, seal, trap), mineral resources (metallic, non-metallic, energy), exploration methods, mining/engineering settings.
1.3 State-VariablesVariablesThe measurable or definable properties that describe system conditions.Metal concentrations, fluid temperature/pressure, reservoir pressure, porosity, permeability, saturation, geothermal gradient, structural stress, hydrothermal flow rate, isotopic compositions, alteration mineralogy, grade variability.
ParameterizationHow variables encode and represent the system’s state.States encoded by resource grade–tonnage curves, P–T–X fluid parameters, reservoir property logs, seismic attributes, geochemical anomalies, alteration mapping indices, ore-body geometry, permeability/porosity relationships, thermal models.
1.4 Admissible IdealizationsSimplificationsConceptual reductions used to make the domain tractable (point masses, rational agents, perfect gases).Homogeneous ore grades, uniform permeability, steady-state hydrothermal flow, simple trap geometry, ideal porphyry zoning models, perfect structural seals, single-phase fluids, equilibrium mineral assemblages, isotropic reservoir properties.
Validity ConditionsThe limits and contexts in which idealizations hold or break down.Valid in early assessments or first-order models; breaks down in heterogeneous deposits, complex structural settings, multiphase flow, reactive transport, faulted reservoirs, supergene overprints, and irregular ore geometries.
1.5 Domain AssumptionsStructural AssumptionsBackground ontological stances such as determinism, continuity, randomness, discreteness.Metallogenic patterns follow tectonic processes; ore formation is governed by fluid flow, magmatism, and physicochemical conditions; petroleum systems follow predictable maturation/migration/trapping pathways; economic extraction depends on measurable physical properties.
Implicit CommitmentsUnstated but necessary assumptions that shape the field’s conceptual structure.Assumes ore grades/geometries can be mapped, geophysical signals correlate with resource properties, geochemical anomalies reflect mineralization, drilling data are representative, and future resource distributions resemble past geological trends.
1.6 Internal Coherence RequirementsConsistencyThe demand that domain concepts do not contradict one another.Requires alignment among geological, geochemical, geophysical, engineering, and economic interpretations; consistent relationships between deposit models, exploration data, and extraction feasibility.
CompatibilityThe requirement that entities, variables, and assumptions fit together into a unified descriptive framework.Integrates mineralogy, petrology, geochemistry, tectonics, geophysics, hydrology, engineering geology, and economics into a unified applied-geoscience decision framework.
2. Evidence Layer2.1 Observable PhenomenaObservablesThe aspects of the domain that can produce detectable signals accessible to measurement.Ore-grade distributions, alteration halos, mineral assemblages, geochemical anomalies, geophysical anomalies (gravity, magnetic, EM, seismic), reservoir pressure/temperature, porosity/permeability logs, fluid compositions, drill core lithology, shows of hydrocarbons or mineralization, fracture networks.
Detection LimitsThe boundaries of what can be resolved or sensed by current instruments or methods.Limited by analytical sensitivity (ppm–ppb chemistry), geophysical resolution, drill spacing, noise in EM/magnetic data, core recovery quality, sampling density, well-log resolution, seismic bandwidth, and depth penetration of each survey method.
2.2 Measurement SystemsUnitsStandardized quantifications (meters, seconds, volts, decibels, dollars, etc.) necessary for consistent comparison.Concentration (ppm, ppb, wt%), grade (% or g/t), porosity (%), permeability (mD–D), flow rate (m³/day), pressure (kPa–MPa), temperature (°C), seismic velocity (m/s), density (g/cc), magnetic susceptibility, resistivity (Ω·m).
InstrumentsDevices and tools (microscopes, spectrometers, sensors, surveys, detectors) used to produce measurements.Drilling rigs, core logging tools, ICP-MS/ICP-OES, XRF, SEM/EDS, microprobe, geophysical survey tools (gravity meters, magnetometers, EM conductors, GPR, seismic sources & receivers), downhole logging tools (NMR, gamma, resistivity), fluid samplers, gas analyzers.
2.3 Operational DefinitionsDefinitionsTerms defined by specific measurement procedures, ensuring empirical clarity.Ore grade defined by economic cutoff; resource/reserve classifications defined by reporting codes (JORC, NI 43-101); reservoir defined by porosity/permeability thresholds; anomaly defined by deviation from background; alteration types defined by diagnostic minerals.
ProceduresThe explicit steps required to perform a measurement in a reproducible way.Core logging, chip sampling, geochemical assays, geophysical surveys, downhole logging, fluid sampling, mineral liberation analysis, petrography, outcrop mapping, drillhole correlation, sample preparation, QA/QC workflows.
2.4 Data AcquisitionProtocolsFormal processes for gathering data under controlled or standardized conditions.Grid/line-based geophysical surveys, systematic drilling patterns, continuous core recovery, composited or interval sampling, geochemical soil/stream-sediment surveys, production testing, well tests, reservoir pressure monitoring, repeat logging.
SamplingRules determining which subset of the domain is measured and how representative it is.Representative drill spacing, stratified sampling across ore zones, duplicate samples for QA/QC, multi-depth well sampling, systematic fluid/gas sampling, geochemical transects, multi-scale geophysical coverage, fracture sampling along boreholes.
2.5 Data Character & FormatData TypesThe form raw evidence takes (time series, spectra, images, counts, qualitative records).Assay tables, geochemical maps, drill logs, core photos, alteration maps, seismic profiles, EM/magnetic grids, well logs, production curves, reservoir property tables, structural sections, 3D block models, resource estimates.
ResolutionThe granularity or precision with which data is captured.Determined by drill spacing, assay precision, seismic/EM frequency, sampling interval, logging-tool resolution, spatial scale of anomalies, geostatistical model resolution, and detection limits of analytical instruments.
2.6 Reliability & CalibrationCalibrationAdjustment procedures ensuring instruments produce accurate results.Instrument calibration (ICP-MS, XRF, EM, seismic, logging tools), standard reference materials, drift correction, QA/QC procedures (blanks, duplicates, standards), geophysical leveling, well-log normalization, calibration of drilling sensors.
Error CharacterizationIdentification and quantification of noise, uncertainty, bias, and measurement error.Sampling bias, grade smearing in composited samples, signal noise in geophysics, core loss, drilling deviation, contamination, matrix effects in assays, inversion non-uniqueness, misidentification of alteration, and statistical uncertainty in resource estimates.
3. Structural Layer3.1 Patterns & RegularitiesLaws / RelationsStable, repeatable patterns governing how observables behave across conditions.Ore formation follows consistent geochemical/tectonic patterns; metal zoning follows temperature/chemical gradients; permeability and porosity control reservoir quality; hydrothermal alteration follows predictable spatial patterns; basin burial controls petroleum maturation; capillary and buoyancy forces govern hydrocarbon trapping; resource grade–tonnage relationships follow statistical regularities.
InvariantsQuantities or properties that remain constant under transformations (symmetries, conservation laws).Characteristic mineral assemblages in specific deposit types, stable metal ratios for certain ore systems, invariant structural controls (faults/fractures) in ore localization, consistent reservoir–seal relationships in petroleum systems, predictable redox and temperature controls in mineral deposition.
3.2 Causal ArchitectureMechanismsUnderlying processes or structures that produce the observed regularities.Magmatic differentiation, fluid exsolution, hydrothermal circulation, metasomatism, pressure–temperature–chemical gradients, structural channeling of fluids, sediment deposition and diagenesis, organic maturation, migration and trapping, supergene enrichment, weathering profiles, density-driven fluid flow.
PathwaysOrganized sequences of interactions forming a causal chain or network.Magma evolution → fluid saturation → metal transport → deposition; basin fill → burial → maturation → migration → trapping; weathering → leaching → residual concentration; groundwater flow → dissolution → precipitation; structural deformation → fracture opening → fluid focusing → mineralization.
3.3 Theoretical VocabularyConceptsCore terms that encode the domain’s structure (force, gene, equilibrium, field).Ore grade, tonnage, cutoff grade, metallogeny, source–pathway–trap–seal, reservoir quality, permeability anisotropy, alteration facies, fluid inclusion, paragenesis, maturation window, trap integrity, redox front, hydrothermal plume.
ClassificationsTaxonomies, categories, or typologies that organize entities and relations.Ore deposit classes (porphyry, VMS, SEDEX, epithermal, IOCG, skarn, orogenic gold), petroleum system categories (conventional/unconventional), reservoir types (clastic, carbonate, fractured), mineralization styles (vein, disseminated, stratiform), alteration types (propylitic, phyllic, potassic, argillic).
3.4 Formal RepresentationsEquationsMathematical constructs expressing laws, relations, or mechanisms.Darcy’s Law for fluid flow, heat-flow equations, solubility and speciation equations, reaction-path equations, partition coefficients, organic maturation kinetics (Arrhenius), capillary-pressure equations, basin-compaction equations, probability distributions for grade/tonnage models, mass-balance equations.
ModelsStructured representations—mathematical, computational, or conceptual—used to predict and explain phenomena.Ore-deposit genetic models, basin-evolution models, petroleum-system models, reservoir simulation models, reactive-transport models, geostatistical resource models, fracture-network models, geothermal models, alteration zoning models.
3.5 Idealized StructuresSimplified ModelsPurposeful abstractions that capture essential dynamics while omitting irrelevant detail.Homogeneous ore bodies, simple vein geometries, uniform reservoir properties, steady-state fluid flow, equilibrium mineral assemblages, perfect seals/traps, linear grade distribution, simple one-phase fluids, isotropic permeability.
Limit ConditionsRegimes where specific models or approximations hold (classical vs. quantum, linear vs. nonlinear).Break down in heterogeneous deposits, faulted reservoirs, multiphase flow, supergene overprinting, structural complexity, variable fluid chemistry, extreme temperature/pressure gradients, diagenetic overprints, chemical reactivity, karstification, and mixed lithologies.
3.6 Integrative FrameworksUnifying TheoriesHigher-order structures that connect disparate laws or mechanisms under a coherent whole.Integration of geochemistry, petrology, tectonics, hydrology, and geophysics into unified models of resource formation and distribution; links fluid flow → chemical evolution → mineralization → geometry → economic recoverability.
Interdisciplinary LinksPoints where the theory connects to adjacent sciences or larger explanatory systems.Intersects with mining engineering, petroleum engineering, hydrogeology, geochemistry, structural geology, environmental science, and economics (resource valuation, extraction economics).
4. Method Layer4.1 Inquiry DesignExperimental DesignStructured plans for manipulating variables to test causal claims.Controlling drilling parameters, fluid chemistry, temperature/pressure in hydrothermal experiments, flow rate in reservoir tests, and geomechanical stress in lab experiments to test ore-forming processes, reservoir properties, and mineral–fluid reactions.
Observational DesignSystematic approaches for gathering non-manipulated data (surveys, field studies, natural experiments).Systematic geological mapping, passive geophysical surveys (seismic, gravity, magnetics, EM), natural hydrothermal observation, monitoring production wells, sampling at natural seeps, observing alteration halos, and tracking natural fluid migration pathways.
4.2 Testing & ValidationHypothesis TestingProcedures for evaluating whether evidence supports or contradicts specific claims.Comparing predicted ore geometries, geochemical anomalies, alteration zoning, reservoir behaviors, trap integrity, and plume migration models with drill-core assays, logging data, seismic attributes, well tests, and geochemical sampling.
ReplicationThe requirement that results be independently reproducible under similar conditions.Repeating assays, geophysical surveys, drillholes along grids, logging runs, fluid sampling, permeability/porosity measurements, tracer tests, resource-block model runs, and geostatistical simulations across multiple datasets or analysts.
4.3 Inference & EvaluationStatistical InferenceRules for drawing conclusions from noisy or incomplete data.Estimating uncertainties in grade, tonnage, reservoir quality, permeability, porosity, flow rates, metal ratios, anomaly significance, geochemical trends, and geostatistical variograms; evaluating sampling representativeness and confidence intervals.
Model ComparisonCriteria (fit, simplicity, predictive accuracy, robustness) used to evaluate competing models.Evaluating competing ore-deposit models, reservoir models, geomechanical models, hydrothermal-flow simulations, resource estimation methods, petroleum-system interpretations, and mine-planning scenarios based on predictive performance.
4.4 Error ManagementError AnalysisIdentification and quantification of random and systematic errors.Identifying sampling errors, assay contamination, core loss, drilling deviation, geophysical noise, inversion non-uniqueness, logging-tool drift, anisotropy misinterpretation in reservoirs, alteration overprint misreads, and geological-mapping bias.
Bias ControlMethods for minimizing subjective, instrumental, or procedural biases.Randomized sampling, QA/QC (duplicates, blanks, standards), blind re-assay, independent geophysical reinterpretation, drill-site spacing optimization, cross-validation in resource modeling, and standardized logging protocols.
4.5 Adjudication & RevisionPeer ScrutinyCollective evaluation of claims through critique, review, and debate.Independent review of resource estimates, geological models, geostatistics, geophysical inversions, reservoir simulations, ore-genesis interpretations, drilling strategies, and development plans across teams or external auditors.
Theory RevisionProcedures for modifying, replacing, or discarding models based on new evidence.Revising deposit models, updating reservoir parameters, recalibrating economic cutoffs, refining flow simulations, adjusting conceptual frameworks, incorporating contradictory drill or geophysical results, and updating grade–tonnage models.
4.6 Integrity ConditionsTransparencyRequirements to disclose methods, data, assumptions, and limitations.Full reporting of sampling protocols, drilling logs, analytical methods, assay QA/QC, modeling assumptions, boundary conditions, geophysical-processing steps, uncertainty quantification, economic cutoffs, and data limitations.
Ethical StandardsNorms ensuring responsible conduct in experimentation, data handling, and publication.Ethical exploration practices, land-access compliance, environmental protection, responsible waste/chemical handling, unbiased reporting, transparency in resource estimation, and adherence to regulatory and professional codes (e.g., JORC, NI 43-101).