Geology Tools

Browse all available geology tools.

Available tools

Active Earth Pressure Calculator Rankine active lateral earth pressure sigma_a = Ka * gamma * z at a given depth behind a vertical wall with a level backfill.
Active Earth Pressure Coefficient Calculator Rankine active earth pressure coefficient Ka = (1 - sin phi) / (1 + sin phi) for a vertical wall and level backfill.
Active Earth Pressure Coefficient Practice Create reproducible practice for Active Earth Pressure Coefficient Calculator from supplied scenarios, returning validated questions and computed answers under the source tool's assumptions and limits.
Active Earth Pressure Practice Create reproducible practice for Active Earth Pressure Calculator from supplied scenarios, returning validated questions and computed answers under the source tool's assumptions and limits.
Activity Number Calculator Compute the Skempton activity A as plasticity index divided by the clay fraction finer than two micrometers, both in percent.
Activity Number Practice Create reproducible practice for Activity Number Calculator from supplied scenarios, returning validated questions and computed answers under the source tool's assumptions and limits.
AFM Diagram Calculator Convert whole-rock oxides to AFM coordinates with ferric iron recalculated to FeO for the tholeiitic-calc-alkaline AFM triangle.
Air Loaded Subsidence Calculator Air-loaded tectonic subsidence with the water column replaced by air (zero load): Y = S(rho_m - rho_s)/rho_m - Wd.
Air Loaded Subsidence Practice Create reproducible practice for Air Loaded Subsidence Calculator from supplied scenarios, returning validated questions and computed answers under the source tool's assumptions and limits.
API Gravity Calculator Convert the specific gravity of crude oil at 60 degrees Fahrenheit to API gravity.
API Gravity Practice Create reproducible practice for API Gravity Calculator from supplied scenarios, returning validated questions and computed answers under the source tool's assumptions and limits.
Apparent Dip Calculator Apparent dip seen on a vertical section: tan(delta_apparent) = tan(delta_true) * cos(theta), where theta is the angle between the section and the dip direction.
Apparent Dip Practice Create reproducible practice for Apparent Dip Calculator from supplied scenarios, returning validated questions and computed answers under the source tool's assumptions and limits.
Argon Diffusion Closure Temperature Calculator Solve the Dodson (1973) closure temperature for argon diffusion given activation energy, diffusion anisotropy and cooling rate.
Argon Diffusion Closure Temperature Practice Create reproducible practice for Argon Diffusion Closure Temperature Calculator from supplied scenarios, returning validated questions and computed answers under the source tool's assumptions and limits.
Atterberg Consistency Index Calculator Compute the consistency index CI = (LL - w) / PI from liquid limit and natural water content in percent and the plasticity index.
Atterberg Consistency Index Practice Create reproducible practice for Atterberg Consistency Index Calculator from supplied scenarios, returning validated questions and computed answers under the source tool's assumptions and limits.
Atterberg Liquidity Index Calculator Compute the liquidity index LI = (w - PL) / PI from natural water content and plastic limit in percent and the plasticity index.
Atterberg Liquidity Index Practice Create reproducible practice for Atterberg Liquidity Index Calculator from supplied scenarios, returning validated questions and computed answers under the source tool's assumptions and limits.
Atterberg Plasticity Index Calculator Compute the plasticity index PI as liquid limit minus plastic limit, both in water-content percent.
Atterberg Plasticity Index Practice Create reproducible practice for Atterberg Plasticity Index Calculator from supplied scenarios, returning validated questions and computed answers under the source tool's assumptions and limits.
Backstripping Subsidence Calculator Water-loaded backstripped tectonic subsidence (Steckler & Watts 1978) with a eustatic correction: Y = S(rho_m - rho_s)/(rho_m - rho_w) - Wd + dSL * rho_w/(rho_m - rho_w). Positive sea-level change means past sea level was higher than present.
Bearing Capacity Factor Nc Calculator Terzaghi/Meyerhof/Vesic cohesion bearing capacity factor Nc = (Nq - 1)*cot(phi), with Nq = exp(pi*tan(phi))*tan^2(45 + phi/2); the exact limit Nc = pi + 2 applies at phi = 0.
Bearing Capacity Factor Nc Practice Create reproducible practice for Bearing Capacity Factor Nc Calculator from supplied scenarios, returning validated questions and computed answers under the source tool's assumptions and limits.
Bearing Capacity Factor Ngamma Calculator Unit-weight bearing capacity factor Ngamma = 2 * (Nq + 1) * tan(phi) with Nq = tan^2(45 + phi/2) * exp(pi * tan(phi)); this is the Vesic (1973) convention, which differs from Terzaghi's and Meyerhof's original third factors. Equals 0 at phi = 0.
Bearing Capacity Factor Ngamma Practice Create reproducible practice for Bearing Capacity Factor Ngamma Calculator from supplied scenarios, returning validated questions and computed answers under the source tool's assumptions and limits.
Bearing Capacity Factor Nq Calculator Surcharge bearing capacity factor Nq = tan^2(45 + phi/2) * exp(pi * tan(phi)), common to Terzaghi, Meyerhof and Vesic; equals 1 at phi = 0.
Bearing Capacity Factor Nq Practice Create reproducible practice for Bearing Capacity Factor Nq Calculator from supplied scenarios, returning validated questions and computed answers under the source tool's assumptions and limits.
Bearing Capacity Meyerhof Calculator Ultimate bearing capacity of a shallow strip footing on the Meyerhof (1963) base equation qu = c*Nc + q*Nq + 0.5*gamma*B*Ngamma with Nq = exp(pi*tan(phi))*tan^2(45 + phi/2), Nc = (Nq - 1)*cot(phi) and Meyerhof's Ngamma = (Nq - 1)*tan(1.4*phi). Base equation only: no shape or depth correction factors applied. c and q in kPa, gamma in kN/m3, B in m.
Bearing Capacity Terzaghi Calculator Ultimate bearing capacity of a shallow strip footing qu = c*Nc + q*Nq + 0.5*gamma*B*Ngamma. Factors: Nq = exp(pi*tan(phi))*tan^2(45 + phi/2), Nc = (Nq - 1)*cot(phi), Ngamma = 2*(Nq + 1)*tan(phi) (Vesic convention for Ngamma; Terzaghi's original third factor differs). Base equation without shape or depth corrections. c and q in kPa, gamma in kN/m3, B in m.
Bearing Capacity Vesic Calculator Ultimate bearing capacity with Vesic (1973) shape and depth factors: qu = c*Nc*sc*dc + q*sq*dq + 0.5*gamma*B*Ngamma*sGamma, dGamma = 1. Factors Nq = exp(pi*tan(phi))*tan^2(45 + phi/2), Nc = (Nq - 1)*cot(phi), Ngamma = 2*(Nq + 1)*tan(phi) (Vesic convention). Shape factors sc = 1 + (B/L)*(Nq/Nc), sq = 1 + (B/L)*tan(phi), sGamma = 1 - 0.4*B/L; depth factors dq = 1 + 2*tan(phi)*(1 - sin(phi))^2*Df/B and dc = dq - (1 - dq)/(Nc*tan(phi)). c and q in kPa, gamma in kN/m3, lengths in m.
Bit Weight On Bit Calculator Determine weight on bit from the difference between off-bottom and on-bottom hook loads.
Brine Density Calculator Compute brine density and dissolved-solids salinity from water mass, salt mass and solution volume.
Brine Salinity Ppm To Ppg Calculator Estimate brine mud weight in pounds per gallon from dissolved-solids salinity in ppm using the linear 0.7 kg/m3 per 1000 ppm rule.
Bubble Point Pressure Vasquez Beggs Calculator Invert the Vasquez-Beggs solution-GOR correlation to obtain the bubble point pressure; pass the separator-corrected gas gravity.
Buckley Leverett Front Saturation Calculator Find the Buckley-Leverett shock-front water saturation by the Welge tangent construction on a Corey fractional-flow curve.
Bulk Density From Porosity Calculator Compute dry bulk density as the product of grain density and (1 - porosity).
Buoyant Density Calculator Compute the buoyant (submerged) density of a saturated soil or rock as saturated density minus water density.
Capillary Pressure Brooks Corey Calculator Evaluate the Brooks-Corey capillary pressure curve Pc = Pe * Se^(-lambda) for a wetting-phase saturation.
Capillary Pressure Van Genuchten Calculator Invert the van Genuchten retention curve Se = [1 + (alpha Pc)^n]^(-m), with m = 1 - 1/n, to obtain capillary pressure in pascals.
Casing Biaxial Stress Calculator Derate the nominal collapse pressure of casing for combined axial tension using the API biaxial correction.
Casing Burst Pressure Calculator Compute the API-style internal burst resistance of casing using the Barlow formula with a 87.5 percent wall tolerance factor.
Casing Collapse Pressure Calculator Compute the thin-wall external collapse resistance of casing from yield strength, outside diameter and wall thickness.
Casing Tension Calculator Compute the effective axial tension at surface for suspended casing, including the buoyancy effect of drilling fluid.
Cement Compressive Strength Calculator Compute unconfined compressive strength of a cement cube from its crush load and specimen dimensions.
Cement Slurry Density Calculator Compute neat cement slurry density and yield per tonne of dry cement from the water/cement mass ratio and cement specific gravity.
Cement Volume Required Calculator Compute the annular capacity and cement slurry volume required to cover a cased interval, including excess.
Choke Flow Rate Gilbert Calculator Estimate the multiphase liquid flow rate through a production choke with the Gilbert (1954) correlation given upstream wellhead pressure, gas-liquid ratio and choke bore.
Clinoform Height Calculator Vertical relief of a clinoform from its along-slope length and foreset dip: h = L * sin(dip).
Clinoform Length Calculator Along-slope length of a clinoform surface from its vertical relief and foreset dip: L = h / sin(dip).
Coefficient Of Consolidation Calculator Coefficient of consolidation cv = Tv * Hd^2 / t rearranged from the Terzaghi time factor, with Tv dimensionless, drainage path Hd in m and time t in years; result in m2/year.
Coefficient Of Volume Compressibility Calculator Coefficient of volume compressibility mv = av / (1 + e0), where av = de / d_sigma' is the slope of the e - sigma' curve over a loading increment. Result in 1/kPa.
Compression Index Calculator Compression index Cc = -(de) / d(log10 sigma') = (e1 - e2) / log10(sigma2' / sigma1') from two points on the virgin consolidation curve. Void ratios dimensionless, effective stresses in kPa.
Consolidation Settlement Calculator Primary consolidation settlement of a normally consolidated fine-grained layer Sc = H * Cc / (1 + e0) * log10(sigma_f' / sigma_i'). Assumes virgin compression with Cc; for overconsolidated ranges use Cr instead. Thickness in m, stresses in kPa, settlement in m.
Cooper Jacob Transmissivity Calculator Compute aquifer transmissivity in square meters per day from constant discharge in cubic meters per day and the semilog drawdown change per log cycle of time in meters.
Core Permeability Klinkenberg Corrected Calculator Apply the Klinkenberg gas-slippage correction kL = kg / (1 + b/Pm) to a steady-state core gas measurement.
Core Porosity Helium Calculator Compute helium-pycnometry porosity from bulk volume and helium-measured grain volume, both in cubic centimetres.
Crystal Fractionation Calculator Rayleigh fractional crystallization C_l = C_0 * F^(D-1) with F the fraction of liquid remaining and D the bulk partition coefficient; concentrations in ppm.
Curvature Coefficient Calculator Compute the gradation curvature coefficient Cc = D30^2 / (D60 * D10) from grain sizes in millimeters read from a gradation curve.
Cuttings Transport Velocity Calculator Determine the net rise velocity and transport ratio of drill cuttings from annular velocity and particle slip velocity.
Darcy Discharge Calculator Compute the total Darcy flow discharge in cubic meters per second as hydraulic conductivity times gradient times cross-sectional area.
Darcy Velocity Calculator Compute the Darcian specific discharge velocity in meters per second as hydraulic conductivity times hydraulic gradient.
Decline Rate Exponential Calculator Evaluate the Arps exponential-decline production rate and cumulative production for a constant decline rate.
Decline Rate Harmonic Calculator Evaluate the Arps harmonic-decline production rate and cumulative production for a unit decline exponent.
Decline Rate Hyperbolic Calculator Evaluate the Arps hyperbolic-decline production rate and cumulative production for a decline exponent between zero and one.
Decompacted Thickness Calculator Grain-volume-conserving decompaction of a compacted unit: t' = t * (1 - porosity) / (1 - target porosity). Porosities are fractions.
Degree Of Consolidation Calculator Average degree of consolidation U inverted from the Terzaghi relations: Tv = (pi/4)*(U/100)^2 for U <= 60 percent and Tv = 1.781 - 0.933*log10(100 - U) for U > 60 percent.
Degree Of Saturation Calculator Compute the degree of saturation as the percentage of the void space filled by water.
Dip Direction To Strike Calculator Convert a dip direction azimuth to the perpendicular strike azimuth (right-hand rule subtracts 90 degrees).
Downlap Angle Calculator Angle between downsloping (progradational) strata and the older surface onto which they downlap: |dip(strata) - dip(basal surface)|, assuming comparable dip directions.
Drilling Hydraulics Bit Nozzle Velocity Calculator Compute bit nozzle velocity and total flow area from circulation rate, nozzle count and nozzle diameter.
Drilling Hydraulics Jet Impact Force Calculator Compute the jet impact force delivered by the bit nozzles from flow rate, mud density and nozzle geometry.
Drilling Hydraulics Pressure Loss Calculator Estimate laminar frictional pressure loss in drill pipe with the Bingham plastic pipe-flow equation.
Dry Density Calculator Compute dry density from wet (bulk) density and gravimetric water content using rho_d = rho / (1 + w).
Earth Pressure At Rest Calculator At-rest lateral earth pressure for a normally consolidated soil via Jaky K0 = 1 - sin(phi): horizontal effective stress sigma_h' = K0 * sigma_v'. Stress in kPa, angle in degrees.
Effective Stress Calculator Compute Terzaghi effective stress as the total vertical stress minus the pore water pressure, both in kPa.
Elastic Thickness Calculator Convert lithospheric elastic thickness to flexural rigidity D = E Te^3 / (12 (1 - nu^2)) with Te in meters, Young's modulus in pascals and rigidity in newton meters.
Epicentral Distance Calculator Great-circle epicentral distance from event to station via the haversine formula on a spherical Earth of mean radius 6371 km.
Fault Heave Calculator Horizontal component of net dip slip on a fault plane: heave = dip slip * cos(dip).
Fault Slip Calculator Compute net slip and the implied dip of the slip vector from the heave (horizontal) and throw (vertical) components of dip-slip displacement.
Fault Throw Calculator Vertical component of net dip slip on a fault plane: throw = dip slip * sin(dip).
Flexural Rigidity Calculator Flexural rigidity of an elastic lithospheric plate: D = E * Te^3 / (12 * (1 - nu^2)).
Fold Interlimb Angle Calculator Interlimb angle in a profile-plane cross section with opposing limb dips measured from horizontal; classified after Fleuty as gentle, open, close, tight or isoclinal.
Fold Wavelength Calculator Estimate the Biot–Ramberg dominant wavelength of a competent viscous layer as 2π times thickness times the cube root of the viscosity contrast divided by six.
Fractional Flow Water Calculator Compute the water fractional flow fw from relative permeabilities and viscosities, neglecting gravity and capillary pressure.
Fracture Pressure Gradient Eaton Calculator Estimate the fracture pressure gradient with the Eaton (1969) relation FG = Pp + nu/(1-nu) * (Sv - Pp).
Gas Compressibility Factor Z Calculator Compute the natural-gas compressibility factor with Sutton pseudo-critical properties and the Dranchuk-Abou-Kassem method.
Gas Density Calculator Compute natural-gas density from the real-gas law using gas gravity and a compressibility factor.
Gas Formation Volume Factor Calculator Compute the gas formation volume factor Bg relating reservoir cubic metres to standard cubic metres at 101.325 kPa and 288.15 K.
Gas Oil Ratio Calculator Compute the producing gas-oil ratio as produced gas volume divided by produced oil volume at standard conditions.
Gas Viscosity Carr Kobayashi Burrows Calculator Compute hydrocarbon gas viscosity with the Carr-Kobayashi-Burrows corresponding-states correlation for sweet gases.
Geologic Time Scale Lookup Map an age in millions of years ago (ICS boundaries) to its Phanerozoic plus Ediacaran period, era and boundary ages; boundary ages belong to the younger period.
Geological Strength Index GSI Calculator Estimate the Hoek Geological Strength Index from the 1976 Rock Mass Rating using the published relation GSI = RMR76 - 5 (valid for RMR76 > 23).
Geology Acid Fracture Conductivity Calculator Ideal etched unpropped channel cubic conductance with independently measured closure retention/channel area, not proppant k×width or acid-treatment efficacy. Caller independently establishes matching units, evidence, method edition and applicability; output is not compliance, diagnosis, work-safety approval, geological identity or validated hazard prediction.
Geology Alumina Saturation Index Asi Calculator MolarA/(correctedC+N+K), independently determined apatite correction; calcium enters denominator unlike peralkalinity. Caller independently establishes matching units, evidence, method edition and applicability; output is not compliance, diagnosis, work-safety approval, geological identity or validated hazard prediction.
Geology Aluminum 26 Beryllium 10 Burial Age Calculator Al26/Be10 ratio burial decay with explicit initial ratio and decay constants; assumes no postburial production, no inferred complex history. Caller independently establishes matching units, evidence, method edition and applicability; output is not compliance, diagnosis, work-safety approval, geological identity or validated hazard prediction.
Geology Apatite Saturation Temperature Calculator Apatite saturation temperature from independently fixed melt-composition same-chemistry phosphorus/temperature calibration; no universal apatite thermometer constants. Conditional independently matched piecewise-linear calibration, no extrapolation. Caller independently establishes matching units, evidence, method edition and applicability; output is not compliance, diagnosis, work-safety approval, geological identity or validated hazard prediction.
Geology Ar Ar Age Calculator Compute an Ar-40/Ar-39 age from the irradiation parameter J and the radiogenic Ar-40/Ar-39 ratio.
Geology Ar Ar Age Practice Create reproducible practice for Geology Ar Ar Age Calculator from supplied scenarios, returning validated questions and computed answers under the source tool's assumptions and limits.
Geology Argon Argon Plateau Age Calculator Bounded contiguous≥3-step observed plateau screen, independent maximum age-span and released-fraction policy; earliest maximum-weight tie, no statistical/geological plateau certification. Caller independently establishes matching units, evidence, method edition and applicability; output is not compliance, diagnosis, work-safety approval, geological identity or validated hazard prediction.
Geology Balanced Cross Section Line Length Calculator Balanced cross-section actual polyline arc-length audit against independent restoration evidence, not end-to-end shortcut. Caller independently establishes matching units, evidence, method edition and applicability; output is not compliance, diagnosis, work-safety approval, geological identity or validated hazard prediction.
Geology Batch Melting Calculator Equilibrium batch melt and solid concentrations constant bulkD; F=0 infinitesimal melt limit, F=1 solid hypothetical not actual inventory. Caller independently establishes matching units, evidence, method edition and applicability; output is not compliance, diagnosis, work-safety approval, geological identity or validated hazard prediction.
Geology Beryllium 10 Concentration To Age Calculator Conditional beryllium10 exposure age from zero initial production pool, no erosion/burial and constant independently matched production N=P/λ(1−exp(−λt)). Inheritance, shielding, depth/scaling, production branch and actual nuclide units independently resolved. Not simple burial radioactive age or an unconstrained geological history.
Geology Biostratigraphy First Appearance Datum Calculator Observed first taxon occurrence bracket on caller increasing depositional coordinate; lower-coverage censoring explicit, not global evolutionary FAD. Caller independently establishes matching units, evidence, method edition and applicability; output is not compliance, diagnosis, work-safety approval, geological identity or validated hazard prediction.
Geology Biostratigraphy Last Appearance Datum Calculator Actual section-positive-up known last fossil occurrence height, unknowns retained. Sampling incompleteness, reworking, erosion, stratigraphic direction and chronological interpretation external; not true extinction age.
Geology Biostratigraphy Zone Thickness Calculator Zone thickness interval from independently observed boundary uncertainty brackets; no exact thickness collapsed from uncertain FAD/LAD. Caller independently establishes matching units, evidence, method edition and applicability; output is not compliance, diagnosis, work-safety approval, geological identity or validated hazard prediction.
Geology Carbon 14 Age Calculator Convert a fraction-modern C-14 measurement into a radiocarbon age in years BP.
Geology Chemostratigraphy Carbon Isotope Excursion Calculator Observed baseline-relative carbon isotope excursions and actual sampled zero-crossings, no named global-event correlation. Caller independently establishes matching units, evidence, method edition and applicability; output is not compliance, diagnosis, work-safety approval, geological identity or validated hazard prediction.
Geology Chlorine 36 Age Calculator Conditional chlorine36 exposure age from zero initial production pool, no erosion/burial and constant independently matched production N=P/λ(1−exp(−λt)). Inheritance, shielding, depth/scaling, production branch and actual nuclide units independently resolved. Not simple burial radioactive age or an unconstrained geological history.
Geology Chlorite Geothermometer Calculator Chlorite composition/temperature conditional same-site calibrated thermometer; caller establishes formula normalization/Fe corrections. Conditional independently matched piecewise-linear calibration, no extrapolation. Caller independently establishes matching units, evidence, method edition and applicability; output is not compliance, diagnosis, work-safety approval, geological identity or validated hazard prediction.
Geology Cipw Norm Calculation Full Calculator Solve full caller independently selected CIPW sequential branch oxide/mineral stoichiometric balance; caller establishes oxidation, volatile removal and normative phases. Not an automatic branch selector or modal mineral identity. Caller independently establishes matching units, evidence, method edition and applicability; output is not compliance, diagnosis, work-safety approval, geological identity or validated hazard prediction.
Geology Conodont Color Alteration Index Cai Calculator Conodont CAI from independently matched color-index/thermal-reference calibration, duration and assemblage held fixed; not uncalibrated color thermometer. Conditional independently matched piecewise-linear calibration, no extrapolation. Caller independently establishes matching units, evidence, method edition and applicability; output is not compliance, diagnosis, work-safety approval, geological identity or validated hazard prediction.
Geology Contaminant Retardation Factor Calculator Equilibrium linear sorption R=1+rhoDryKd/nEffective, independently calibrated contaminant/medium Kd, not reactive kinetics. Caller independently establishes matching units, evidence, method edition and applicability; output is not compliance, diagnosis, work-safety approval, geological identity or validated hazard prediction.
Geology Cooling Rate From Age Vs Closure Temp Calculator Fit temperature against age-before-present across matched closure systems; positive slope corresponds forward-time cooling, negative apparent cooling retained, no causal thermal history. Caller independently establishes matching units, evidence, method edition and applicability; output is not compliance, diagnosis, work-safety approval, geological identity or validated hazard prediction.
Geology Cosmogenic Carbon 14 Age Calculator Conditional cosmogenic carbon14 exposure age from zero initial production pool, no erosion/burial and constant independently matched production N=P/λ(1−exp(−λt)). Inheritance, shielding, depth/scaling, production branch and actual nuclide units independently resolved. Not simple burial radioactive age or an unconstrained geological history.
Geology Cosmogenic Erosion Rate Calculator Steady single-production exponential erosion inversion, independently steady state/full shielding history assumed; negative erosion branch refused, not exposure age. Caller independently establishes matching units, evidence, method edition and applicability; output is not compliance, diagnosis, work-safety approval, geological identity or validated hazard prediction.
Geology Cosmogenic Exposure Age Calculator Conditional actual independently resolved cosmogenic nuclide exposure age from zero initial production pool, no erosion/burial and constant independently matched production N=P/λ(1−exp(−λt)). Inheritance, shielding, depth/scaling, production branch and actual nuclide units independently resolved. Not simple burial radioactive age or an unconstrained geological history.
Geology Cosmogenic Helium 3 Age Calculator Stable cosmogenic helium-3 zero-initial-pool/noerosion age, N/P; noncosmogenic helium, shielding and matched production independently resolved. Actual independently matched quantities/units required; not infer causal effect, clinical guidance or safe design.
Geology Cosmogenic Nuclide Production Rate Calculator Declared single spallogenic exponential production-depth model with independent reference/site scaling; not inferred latitude/altitude scaling or muon production. Caller independently establishes matching units, evidence, method edition and applicability; output is not compliance, diagnosis, work-safety approval, geological identity or validated hazard prediction.
Geology Crater Diameter Scaling Calculator Conditional independently matched piecewise-linear crater diameter scaling at fixed actual target, impactor velocity, gravity and scaling regime reference interpolation. Strictly increasing verifiedImpactorCoordinateKnots and aligned same-unit verifiedCraterDiameterMetersKnots required, no extrapolation. Examples are illustrative knots, not verified normative data; actual calibration, branch selection, uncertainty and applicability external. Not automatic parameter fitting, physical identity, clinical recommendation or a validated hazard forecast.
Geology Critical Taper Wedge Angle Calculator Observed wedge taperα+βunder actual signed dip convention. This does NOT derive critical Coulombtaper from pore pressure/friction, or demonstrate critical state, tectonic activity or stability.
Geology Crustal Residence Time Calculator Exact caller independently verified Geology Crustal Residence Time Calculator reference lookup. Required actual context: actual independently established crustal-residence isotopic model, reservoir evolution, initial ratio, decay system, two-stage assumptions and model edition; not identical crystallization or depleted-mantle TDMage. Illustrative records are not authoritative data. No universal material coefficient, law, norm, medical limit, diagnosis, clinical dose, work-safety approval, engineering design or guaranteed forecast is inferred. This operation retrieves actual qualified reference text; it does not calculate a missing physical model or verify the truth of supplied evidence.
Geology Dendrochronology Cross Dating Calculator Bounded actual ring-width candidate crossdating Pearson correlation; tied offsets retained, chronology/authenticity not established. Caller independently establishes matching units, evidence, method edition and applicability; output is not compliance, diagnosis, work-safety approval, geological identity or validated hazard prediction.
Geology Dendrochronology Ring Width Index Calculator Measured/independently detrended expected ring-width indices, not invented detrending model or raw crossdating correlations. Caller independently establishes matching units, evidence, method edition and applicability; output is not compliance, diagnosis, work-safety approval, geological identity or validated hazard prediction.
Geology Depleted Mantle Model Age Calculator Compute the single-stage Sm-Nd depleted-mantle (T_DM) model age of a sample from its Nd isotope ratios.
Geology Differentiation Index Di Calculator Actual independently selected Q+Or+Ab+Nef+Lc differentiation-index percentage of complete same-basis independently computed norm. Weight/volume basis and mineral assignment external, not compute full CIPWnorm or actual observed mineral mode.
Geology Dunham Carbonate Classification Lookup Screen depositional texture/mud/grain-support evidence under caller Dunham criteria; not identification by grain size alone. Independently declared positive evidence requirements; overlapping/unknown classes retained. Caller independently establishes matching units, evidence, method edition and applicability; output is not compliance, diagnosis, work-safety approval, geological identity or validated hazard prediction.
Geology Effective Porosity Calculator Connected tracer volume excluding independently resolved dead ends, unlike total pore/grain-density porosity. Caller independently establishes matching units, evidence, method edition and applicability; output is not compliance, diagnosis, work-safety approval, geological identity or validated hazard prediction.
Geology Electron Spin Resonance Age Calculator electron-spin resonance actual equivalent-dose/dose-rate age under independently resolved fading, uptake, water and saturation assumptions. Actual independently matched quantities/units required; not infer causal effect, clinical guidance or safe design.
Geology Exhumation Rate From Cooling Rate Calculator Conditional cooling/gradient apparent exhumation, signed heating/subsidence retained; caller assumes stationary gradient and no independent transient thermal change. Caller independently establishes matching units, evidence, method edition and applicability; output is not compliance, diagnosis, work-safety approval, geological identity or validated hazard prediction.
Geology Fault Bend Fold Kink Angle Calculator Measured signed section kink rotations for fault-bend fold restoration; no unsupported ramp-to-kink inversion. Caller independently establishes matching units, evidence, method edition and applicability; output is not compliance, diagnosis, work-safety approval, geological identity or validated hazard prediction.
Geology Fault Gouge Thickness Calculator Actual mapped normal traverse, left-interval gouge flags; caller distinguishes observed segments from unobserved geological continuation. Caller independently establishes matching units, evidence, method edition and applicability; output is not compliance, diagnosis, work-safety approval, geological identity or validated hazard prediction.
Geology Fault Seal Capacity Sgr Calculator Throw-window independently mapped clay volume inventory SGR; not calibrated seal pressure or actual fault continuity. Caller independently establishes matching units, evidence, method edition and applicability; output is not compliance, diagnosis, work-safety approval, geological identity or validated hazard prediction.
Geology Fe Number Calculator Explicit 100Fe²⁺/(Fe²⁺+Mg) molar Fenumber, not total ferric+ferrous mass fraction or existing magnesium number. Oxidation, chemical analysis and molar conversion external.
Geology Fission Track Central Age Calculator Explicit zero-overdispersion fixed-effects fission-track central log-age estimate with independent grain variances; not pooled track-count age or estimated random-effects dispersion. Caller independently establishes matching units, evidence, method edition and applicability; output is not compliance, diagnosis, work-safety approval, geological identity or validated hazard prediction.
Geology Fission Track Chi Square Test Calculator Pearson grain×track-origin contingency homogeneity statistic; explicit integer counts, no automatic central-age validity or chi-square p approximation. Caller independently establishes matching units, evidence, method edition and applicability; output is not compliance, diagnosis, work-safety approval, geological identity or validated hazard prediction.
Geology Flexural Slip Restoration Calculator Concentric flexural-slip h×signed bend radians across independently matched adjacent beds; orientation and slip sign retained. Caller independently establishes matching units, evidence, method edition and applicability; output is not compliance, diagnosis, work-safety approval, geological identity or validated hazard prediction.
Geology Fluid Inclusion Homogenization Temperature Calculator Inventory homogenization measurements within independently same-generation inclusion family; not trapping temperature without pressure correction. Caller independently establishes matching units, evidence, method edition and applicability; output is not compliance, diagnosis, work-safety approval, geological identity or validated hazard prediction.
Geology Fluid Inclusion Salinity From Ice Melting Calculator Bodnar 1993 NaCl-water ice liquidus 1.78d−.0442d²+.000557d³ wt%NaCl equivalent, not mixed salt composition; final ice melting not homogenization. Caller independently establishes matching units, evidence, method edition and applicability; output is not compliance, diagnosis, work-safety approval, geological identity or validated hazard prediction.
Geology Folk Sandstone Classification Lookup Normalized QFL framework coordinates against caller verified same-method Folk polygons, matrix fraction externally established. Shared boundaries and overlaps retained; polygons must be simple non-self-intersecting. Caller independently establishes matching units, evidence, method edition and applicability; output is not compliance, diagnosis, work-safety approval, geological identity or validated hazard prediction.
Geology Foreland Basin Flexural Subsidence Calculator Infinite elastic beam/plate strip on linear buoyant foundation under line load; signed forebulge retained, not local Airy compensation. Caller independently establishes matching units, evidence, method edition and applicability; output is not compliance, diagnosis, work-safety approval, geological identity or validated hazard prediction.
Geology Fractional Melting Calculator Perfect fractional extraction accumulated/instantaneous melts; constant bulkD, distinct from residual-liquid Rayleigh crystal fractionation. Caller independently establishes matching units, evidence, method edition and applicability; output is not compliance, diagnosis, work-safety approval, geological identity or validated hazard prediction.
Geology Fracture Permeability Parallel Plate Calculator Smooth ideal fracture intrinsic k=b²/12, independently established hydraulic apertures, not visual width or bulk rock permeability. Caller independently establishes matching units, evidence, method edition and applicability; output is not compliance, diagnosis, work-safety approval, geological identity or validated hazard prediction.
Geology Fracture Porosity Calculator Actual area×aperture fracture inventory with mapped overlap subtraction, not inferred permeability. Caller independently establishes matching units, evidence, method edition and applicability; output is not compliance, diagnosis, work-safety approval, geological identity or validated hazard prediction.
Geology Fracture Transmissivity Cubic Law Calculator Fluid-dependent cubic-lawρgb³/(12μ) fracture transmissivity; distinct from intrinsic b²/12. Caller independently establishes matching units, evidence, method edition and applicability; output is not compliance, diagnosis, work-safety approval, geological identity or validated hazard prediction.
Geology Garnet Biotite Geothermometer Calculator Conditional independently matched piecewise-linear actual garnet/biotite geothermometer calibration with pressure, activities and composition domain reference interpolation. Strictly increasing verifiedExchangeCoefficientKnots and aligned same-unit verifiedTemperatureKelvinKnots required, no extrapolation. Examples are illustrative knots, not verified normative data; actual calibration, branch selection, uncertainty and applicability external. Not automatic parameter fitting, physical identity, clinical recommendation or a validated hazard forecast.
Geology Garnet Clinopyroxene Geothermometer Calculator Conditional independently matched piecewise-linear actual garnet/clinopyroxene geothermometer calibration at fixed pressure/activities reference interpolation. Strictly increasing verifiedExchangeCoefficientKnots and aligned same-unit verifiedTemperatureKelvinKnots required, no extrapolation. Examples are illustrative knots, not verified normative data; actual calibration, branch selection, uncertainty and applicability external. Not automatic parameter fitting, physical identity, clinical recommendation or a validated hazard forecast.
Geology Geomechanics Brazilian Tensile Strength Calculator Ideal Brazilianrockdisk diametral tensile stress2P/(πDt), actual valid test/specimen and crack mode independently qualified. Not direct tensile strength, compressive stress or generalized anisotropic solution.
Geology Geomechanics Coal Gas Content Langmuir Calculator Calibrated coal LangmuirgasCONTENTVL P/(PL+P), actual moisture/temperature and gas reference-volume basis required. Not chemistry fractional surface coverage or total free+adsorbed gas.
Geology Geomechanics Deformation Modulus Hoek Diederichs Calculator Exact caller independently verified Geology Geomechanics Deformation Modulus Hoek Diederichs Calculator reference lookup. Required actual context: actual Hoek–Diederichsdeformation modulus equation version, GSI, D, rock modulus and verified empirical domain; no undeclared unit/prefactor/model variant or unverified reservoir estimate. Illustrative records are not authoritative data. No universal material coefficient, law, norm, medical limit, diagnosis, clinical dose, work-safety approval, engineering design or guaranteed forecast is inferred. This operation retrieves actual qualified reference text; it does not calculate a missing physical model or verify the truth of supplied evidence.
Geology Geomechanics Hydrate Stability Zone Thickness Calculator Observed geothermal profile vs independent matching pressure/composition hydrate boundary; integrate stability-positive intervals with linear crossings, no inferred gas presence or outside-coverage thickness. Caller independently establishes matching units, evidence, method edition and applicability; output is not compliance, diagnosis, work-safety approval, geological identity or validated hazard prediction.
Geology Geomechanics Landslide Factor Of Safety Janbu Calculator Bounded positive-branch Janbu simplified slice equilibrium with independent correction factor, pore pressure/friction actual slice evidence; not a Bishop formula renamed or slope safety certification. Caller independently establishes matching units, evidence, method edition and applicability; output is not compliance, diagnosis, work-safety approval, geological identity or validated hazard prediction.
Geology Geomechanics Mohr Coulomb Cohesion From Hoek Brown Calculator FIT equivalent MC cohesion/friction over independently chosen confinement-window sampled Hoek–Brown envelope, not universal mapping or exact nonlinear envelope. Caller independently establishes matching units, evidence, method edition and applicability; output is not compliance, diagnosis, work-safety approval, geological identity or validated hazard prediction.
Geology Geomechanics Reservoir Compaction Calculator Declared small-strain reservoir thickness×uniaxial compaction coefficient×actual depletion; actual stress path and effective-pressure applicability independently established. Signed expansion retained, not subsidence geometry or geomechanical safety.
Geology Geomechanics Salt Creep Rate Calculator Exact caller independently verified Geology Geomechanics Salt Creep Rate Calculator reference lookup. Required actual context: actual salt creep constitutive law, stress/temperature history, activation and independently fitted parameters; no undeclared unit/prefactor/model variant or unverified reservoir estimate. Illustrative records are not authoritative data. No universal material coefficient, law, norm, medical limit, diagnosis, clinical dose, work-safety approval, engineering design or guaranteed forecast is inferred. This operation retrieves actual qualified reference text; it does not calculate a missing physical model or verify the truth of supplied evidence.
Geology Geomechanics Shale Gas Total Gas Content Calculator Actual independently partitioned adsorbed/free/dissolved shale gas on SAMEstandard-volume/mass basis, signed-free nonnegative inventory. No infer components, resource recovery or reservoir capacity from porosity alone.
Geology Geomechanics Unconfined Compressive Strength UCS Calculator Actual intact-rock UCSaxial failure force/original specimen area, not structural pillar capacity or borehole failure model. Actual independently matched quantities/units required; not infer causal effect, clinical guidance or safe design.
Geology Geomechanics Wellbore Stability Mud Weight Window Calculator Actual actual mud density versus independently modeled collapse/fracture review window with depth, pore pressure/stress and fluid convention externally resolved versus independently applicable ordered caller review bounds in same caller mud-density unit. Endpoints inclusive, all margins signed. No default benchmark, universal threshold, compliance, medical reassurance or safe operation approval; authoritative protocol/context and measurement uncertainty external.
Geology Geothermal Gradient Calculator Actual two-level temperature/depth geothermal gradient, not presume conductive heat flow or reservoir extrapolation.
Geology Geothermal Heat Flow Calculator Conductive upward heat fluxk×downward-positive temperature gradient, SIcoherent. Signed flux retained, not convective geothermal heat or resource/safety assessment.
Geology Geothermal Reservoir Temperature Calculator Exact caller independently verified Geology Geothermal Reservoir Temperature Calculator reference lookup. Required actual context: geothermal reservoir temperature geothermometer calibration, solute activities, mixing/reequilibration and actual method; no incomplete inputs silently determine a universal predictive number. Illustrative records are not authoritative data. No universal material coefficient, law, norm, medical limit, diagnosis, clinical dose, work-safety approval, engineering design or guaranteed forecast is inferred. This operation retrieves actual qualified reference text; it does not calculate a missing physical model or verify the truth of supplied evidence.
Geology Hafnium Epsilon Calculator Express a measured 176Hf/177Hf ratio as epsilon-Hf relative to the chondritic uniform reservoir (CHUR).
Geology Helium Age Correction Alpha Ejection Calculator Simple independent FTalpha-retention division age/FT, not derive FTfrom grain shape, correct zoning/diffusion or resolve parent/helium production.
Geology Helium Diffusion Coefficient Calculator Mineral-specific independently fitted helium Arrheniusdiffusion D0exp(−Ea/RT), J/molactivation, SIprefactor. Not semiconductor dopant diffusion, closure temperature or helium retention model; grain orientation/defects independently verified.
Geology Hydraulic Conductivity Hazen Calculator Explicit hydraulic conductivity KH=C*d10²with diameter meters and independently calibrated Cunits1/(m·s). Applicable granular-soil domain externally verified; not intrinsic permeability, mixed cm/mmformula or universally fitted Hazenconstant.
Geology Hydraulic Fracture Conductivity Calculator Measured matched proppant-pack k×retained width conductivities, caller establishes closure stress/fluid basis; not whole-fracture productivity. Caller independently establishes matching units, evidence, method edition and applicability; output is not compliance, diagnosis, work-safety approval, geological identity or validated hazard prediction.
Geology Hydraulic Fracture Half Length Pkins Calculator Exact caller independently verified Geology Hydraulic Fracture Half Length Pkins Calculator reference lookup. Required actual context: actual PKNhydraulic-fracture half-length evolution with declared viscosity/leakoff/toughness regime, plane-strain modulus, fracture height, rate, time and prefactor convention; no incomplete inputs silently determine a universal predictive number. Illustrative records are not authoritative data. No universal material coefficient, law, norm, medical limit, diagnosis, clinical dose, work-safety approval, engineering design or guaranteed forecast is inferred. This operation retrieves actual qualified reference text; it does not calculate a missing physical model or verify the truth of supplied evidence.
Geology Illite Crystallinity Kubler Index Calculator Observed illite001FWHM2theta Gaussian instrument correction; same-standard preparation required, no metamorphic grade or Gaussian assumption inferred. Caller independently establishes matching units, evidence, method edition and applicability; output is not compliance, diagnosis, work-safety approval, geological identity or validated hazard prediction.
Geology Joint Roughness Coefficient Jrc Calculator JRC interpolation from caller independently measured same-scale/sampling roughness coordinates and verified JRC calibration, no universal visual JRC estimator. Conditional independently matched piecewise-linear calibration, no extrapolation. Caller independently establishes matching units, evidence, method edition and applicability; output is not compliance, diagnosis, work-safety approval, geological identity or validated hazard prediction.
Geology Joint Shear Strength Barton Bandis Calculator Ideal joint peak shear τ=σn tan[JRC log10(JCS/σn)+φr], same stress units. Actual scale/weathering/normal stress applicability and JRC/JCSindependent; valid angle0–<90°, not residual shear or structural safety.
Geology K Ar Age Calculator Compute a K-Ar age from radiogenic Ar-40 and K-40 amounts using the Steiger & Jager (1977) decay constants.
Geology K Ar Age With Atmospheric Correction Calculator K–Ar branched decay with independently atmospheric40Ar/36Ar correction and common atom/mole units; not supplied radiogenic ratio-only age. Caller independently establishes matching units, evidence, method edition and applicability; output is not compliance, diagnosis, work-safety approval, geological identity or validated hazard prediction.
Geology Kurtosis Folk Ward Calculator Folk–Ward tail/interquartile PHI spread ratio, not moment kurtosis. Caller independently establishes matching units, evidence, method edition and applicability; output is not compliance, diagnosis, work-safety approval, geological identity or validated hazard prediction.
Geology Landslide Volume Calculator Actual matched pre/post survey-cell removal AND deposition; overlapping cells excluded by caller, no depth×area proxy. Caller independently establishes matching units, evidence, method edition and applicability; output is not compliance, diagnosis, work-safety approval, geological identity or validated hazard prediction.
Geology Lava Flow Length Jeffreys Calculator Exact caller independently verified Geology Lava Flow Length Jeffreys Calculator reference lookup. Required actual context: Jeffreyslava flow model, geometry, cooling/rheology, time and actual runout convention; no incomplete inputs silently determine a universal predictive number. Illustrative records are not authoritative data. No universal material coefficient, law, norm, medical limit, diagnosis, clinical dose, work-safety approval, engineering design or guaranteed forecast is inferred. This operation retrieves actual qualified reference text; it does not calculate a missing physical model or verify the truth of supplied evidence.
Geology Lead Isotope Ratio Calculator Normalize measured lead isotope amounts to 204Pb to obtain the standard 206Pb/204Pb, 207Pb/204Pb and 208Pb/204Pb ratios.
Geology Lu Hf Isochron Calculator Fit a two-point Lu-Hf isochron and convert its slope to an age using the Lu-176 decay constant.
Geology Luminescence Equivalent Dose Calculator Equivalent dose from independently fixed same-aliquot normalized luminescence growth curve; saturation, bleaching and dose-rate age conversion not inferred. Conditional independently matched piecewise-linear calibration, no extrapolation. Caller independently establishes matching units, evidence, method edition and applicability; output is not compliance, diagnosis, work-safety approval, geological identity or validated hazard prediction.
Geology Magma Ascent Velocity Calculator Exact caller independently verified Geology Magma Ascent Velocity Calculator reference lookup. Required actual context: magma ascent model, rheology, conduit geometry, density, driving pressure and multiphase assumptions; no incomplete inputs silently determine a universal predictive number. Illustrative records are not authoritative data. No universal material coefficient, law, norm, medical limit, diagnosis, clinical dose, work-safety approval, engineering design or guaranteed forecast is inferred. This operation retrieves actual qualified reference text; it does not calculate a missing physical model or verify the truth of supplied evidence.
Geology Magnetostratigraphy Polarity Lookup Resolve independently verified named polarity chron/edition evidence, not geomagnetic-age assignment without reference. Exact independently verified location/jurisdiction/method/edition reference key, not a live database. Caller independently establishes matching units, evidence, method edition and applicability; output is not compliance, diagnosis, work-safety approval, geological identity or validated hazard prediction.
Geology Magnetostratigraphy Reversal Frequency Calculator Actual magnetostratigraphic identified reversals per complete recorded Ma, not polarity chrons boundary ambiguity, true unsampled reversal frequency or geomagnetic forecast. Actual independently matched quantities/units required; not infer causal effect, clinical guidance or safe design.
Geology Mid Ocean Ridge Spreading Rate Half Calculator Declared symmetric half-spreading rate from full conjugate distance and actual duration, km/Ma=mm/yr. Symmetry/reconstruction external; not single-flank distance silently halved.
Geology Mineral Chemistry Cation Calculation Calculator Actual mineral oxide-to-cation oxygen-basis normalization with caller independently verified oxide stoichiometry/molar masses and mineral oxygen basis. Not infer valence, site occupancy, Feoxidation, volatile deficits or mineral classification.
Geology Mixing Hyperbola Calculator Concentration-weighted two-endmember isotope mixing hyperbola on declared common denominator, not arithmetic isotope mean. Caller independently establishes matching units, evidence, method edition and applicability; output is not compliance, diagnosis, work-safety approval, geological identity or validated hazard prediction.
Geology Monazite Chemical Age Chime Calculator CHIME conditional chemical age from independently matched monazite total-Pb/Th/U equivalent chemical-age calibration, common-Pb/decay/oxide basis externally fixed. Conditional independently matched piecewise-linear calibration, no extrapolation. Caller independently establishes matching units, evidence, method edition and applicability; output is not compliance, diagnosis, work-safety approval, geological identity or validated hazard prediction.
Geology Nb Ta Anomaly Calculator Nb/Ta anomalies against geometric interpolation of independently specified normalized bracketing trace elements; reference/order explicitly caller established, not Ce/Eu substitution. Caller independently establishes matching units, evidence, method edition and applicability; output is not compliance, diagnosis, work-safety approval, geological identity or validated hazard prediction.
Geology Neodymium Epsilon Calculator Express a measured 143Nd/144Nd ratio as epsilon-Nd relative to the chondritic uniform reservoir (CHUR).
Geology Niggli Value Al Calculator Declared Niggli al=100group-equivalent moles/Σ(al+fm+c+alk). Oxide molar conversions, Feoxidation and grouping independently performed under actual Niggliconvention; not raw wt%normalization or full Niggli mineral analysis.
Geology Niggli Value Alk Calculator Declared Niggli alk=100group-equivalent moles/Σ(al+fm+c+alk). Oxide molar conversions, Feoxidation and grouping independently performed under actual Niggliconvention; not raw wt%normalization or full Niggli mineral analysis.
Geology Niggli Value C Calculator Declared Niggli c=100group-equivalent moles/Σ(al+fm+c+alk). Oxide molar conversions, Feoxidation and grouping independently performed under actual Niggliconvention; not raw wt%normalization or full Niggli mineral analysis.
Geology Niggli Value Fm Calculator Declared Niggli fm=100group-equivalent moles/Σ(al+fm+c+alk). Oxide molar conversions, Feoxidation and grouping independently performed under actual Niggliconvention; not raw wt%normalization or full Niggli mineral analysis.
Geology Normative Color Index Calculator Actual independently selected mafic normative mineral color-index percentage of complete same-basis independently computed norm. Weight/volume basis and mineral assignment external, not compute full CIPWnorm or actual observed mineral mode.
Geology Oxygen Isotope Paleotemperature Calculator Estimate carbonate formation temperature from calcite and water delta-18O values using the Epstein-Craig paleotemperature equation.
Geology Oxygen Isotope Thermometer Quartz Magnetite Calculator Conditional independently matched piecewise-linear actual equilibrium quartz/magnetite isotope thermometry under verified fractionation calibration reference interpolation. Strictly increasing verifiedFractionationCoordinateKnots and aligned same-unit verifiedTemperatureKelvinKnots required, no extrapolation. Examples are illustrative knots, not verified normative data; actual calibration, branch selection, uncertainty and applicability external. Not automatic parameter fitting, physical identity, clinical recommendation or a validated hazard forecast.
Geology Paleocurrent Direction Calculator Weighted circular mean of independently tilt-corrected directional paleocurrent measurements; canceling resultant rejected. Caller independently establishes matching units, evidence, method edition and applicability; output is not compliance, diagnosis, work-safety approval, geological identity or validated hazard prediction.
Geology Paleomagnetic Fold Test Calculator Observed unfolding-concentration fold-test screen from independent unit-vector rotations; ties retained, no bootstrap confidence or primary magnetization certification. Caller independently establishes matching units, evidence, method edition and applicability; output is not compliance, diagnosis, work-safety approval, geological identity or validated hazard prediction.
Geology Paleomagnetic Inclination To Paleolatitude Calculator Ideal GADtanI=2tanλpaleolatitude signed branch, actual independently corrected inclination. Hemisphere/reversal convention, flattening, tectonic rotation and nondipole field external; not full pole position.
Geology Paleomagnetic Pole Position Calculator Exact caller independently verified Geology Paleomagnetic Pole Position Calculator reference lookup. Required actual context: actual virtual geomagnetic pole/site coordinates, declination/inclination, dipole/reversal/sign conventions and independently verified coordinate model; no incomplete inputs silently determine a universal predictive number. Illustrative records are not authoritative data. No universal material coefficient, law, norm, medical limit, diagnosis, clinical dose, work-safety approval, engineering design or guaranteed forecast is inferred. This operation retrieves actual qualified reference text; it does not calculate a missing physical model or verify the truth of supplied evidence.
Geology Paleoslope Calculator Paleoslope angle from independently reconstructed drop and horizontal run. Actual reconstruction, compaction/tectonic correction and transport model external; not infer ancient slope from grain size alone.
Geology Pb Pb Isochron Calculator Fit actual Pb–Pb isotope array then invert independently verified radiogenic slope/age curve (same U isotope ratio/decay constants); no log1p applied to Pb–Pb slope. Caller independently establishes matching units, evidence, method edition and applicability; output is not compliance, diagnosis, work-safety approval, geological identity or validated hazard prediction.
Geology Peralkalinity Index Calculator Molar(Na2O+K2O)/Al2O3, independently matched molar masses not weight sum. Caller independently establishes matching units, evidence, method edition and applicability; output is not compliance, diagnosis, work-safety approval, geological identity or validated hazard prediction.
Geology Permeability Hazen Calculator Bounded offline reference: Hazenempirical d10law usually estimates hydraulic conductivity, not intrinsic permeability. Conversion to intrinsic permeability requires fluid dynamic viscosity, density and gravity. Source: Hazen granular-soil empirical conductivity relation and Darcylaw dimensional analysis. Coefficient units, grain-size applicability and actual fluid state externally verified; intrinsic permeability in m²is not hydraulic conductivity in m/s. Topic keys: summary, reference, limitations. Not a complete/current reference corpus, individual outcome, legal/design compliance or safety certification.
Geology Permeability Kozeny Carman Calculator Kozeny–Carman intrinsic permeability with independently calibrated grain convention/geometry factor, not hydraulic conductivity. Caller independently establishes matching units, evidence, method edition and applicability; output is not compliance, diagnosis, work-safety approval, geological identity or validated hazard prediction.
Geology Petrophysical Borehole Image Fracture Density Calculator Linear image fracture counts per actual imaged length; explicit completeness fractions, no areal network or assumed full borehole coverage. Caller independently establishes matching units, evidence, method edition and applicability; output is not compliance, diagnosis, work-safety approval, geological identity or validated hazard prediction.
Geology Petrophysical Cementation Exponent M Calculator FIT fully brine-saturated core ArchieF=aφ^(−m) data, not supplied exponent forward resistance or partial-saturation estimate. Caller independently establishes matching units, evidence, method edition and applicability; output is not compliance, diagnosis, work-safety approval, geological identity or validated hazard prediction.
Geology Petrophysical Dielectric Permittivity Calculator CRIM square-root volumetric dielectric mixing with independently measured same-frequency phases; not lithology identity or DC conductivity. Caller independently establishes matching units, evidence, method edition and applicability; output is not compliance, diagnosis, work-safety approval, geological identity or validated hazard prediction.
Geology Petrophysical Formation Factor Archie Calculator Independently calibrated Archieformation factorF=aφ^−m, dimensionless interconnected porosity. Not saturation, shaley conductivity model or universal m=2coefficient.
Geology Petrophysical Nmr Permeability Coates Calculator Exact caller independently verified Geology Petrophysical Nmr Permeability Coates Calculator reference lookup. Required actual context: actual CoatesNMRpermeability coefficient/units, porosity, bound/free fluid cutoff and calibrated exponents; no undeclared unit/prefactor/model variant or unverified reservoir estimate. Illustrative records are not authoritative data. No universal material coefficient, law, norm, medical limit, diagnosis, clinical dose, work-safety approval, engineering design or guaranteed forecast is inferred. This operation retrieves actual qualified reference text; it does not calculate a missing physical model or verify the truth of supplied evidence.
Geology Petrophysical Shaly Sand Simandoux Water Saturation Calculator Exact caller independently verified Geology Petrophysical Shaly Sand Simandoux Water Saturation Calculator reference lookup. Required actual context: actual Simandouxconductance equation/shalefraction, porosity, formation/shalewater resistivities, cementation/saturation exponents and calibrated branch; no undeclared unit/prefactor/model variant or unverified reservoir estimate. Illustrative records are not authoritative data. No universal material coefficient, law, norm, medical limit, diagnosis, clinical dose, work-safety approval, engineering design or guaranteed forecast is inferred. This operation retrieves actual qualified reference text; it does not calculate a missing physical model or verify the truth of supplied evidence.
Geology Petrophysical Waxman Smits Water Saturation Calculator Exact caller independently verified Geology Petrophysical Waxman Smits Water Saturation Calculator reference lookup. Required actual context: actual Waxman–Smitswater saturation equation, CECper pore volume, ionic equivalent conductance, formation/brine resistivity and calibration; no undeclared unit/prefactor/model variant or unverified reservoir estimate. Illustrative records are not authoritative data. No universal material coefficient, law, norm, medical limit, diagnosis, clinical dose, work-safety approval, engineering design or guaranteed forecast is inferred. This operation retrieves actual qualified reference text; it does not calculate a missing physical model or verify the truth of supplied evidence.
Geology Proppant Pack Permeability Calculator Exact caller independently verified Geology Proppant Pack Permeability Calculator reference lookup. Required actual context: actual proppant pack permeability under closure stress, particle distribution, embedment, fluid and independently verified permeability experiment; no incomplete inputs silently determine a universal predictive number. Illustrative records are not authoritative data. No universal material coefficient, law, norm, medical limit, diagnosis, clinical dose, work-safety approval, engineering design or guaranteed forecast is inferred. This operation retrieves actual qualified reference text; it does not calculate a missing physical model or verify the truth of supplied evidence.
Geology Provenance Index Calculator ZTR maturity inventory among identified transparent heavy minerals, excluding opaque fractions; not proof of provenance. Caller independently establishes matching units, evidence, method edition and applicability; output is not compliance, diagnosis, work-safety approval, geological identity or validated hazard prediction.
Geology Pyroclastic Flow Runout Calculator Exact caller independently verified Geology Pyroclastic Flow Runout Calculator reference lookup. Required actual context: actual pyroclastic flow runout model/topography, volume, entrainment and applicability; no incomplete inputs silently determine a universal predictive number. Illustrative records are not authoritative data. No universal material coefficient, law, norm, medical limit, diagnosis, clinical dose, work-safety approval, engineering design or guaranteed forecast is inferred. This operation retrieves actual qualified reference text; it does not calculate a missing physical model or verify the truth of supplied evidence.
Geology QAPF Classification Lookup Independently normalized same-triangle QAPF coordinates and verified polygons; caller resolves quartz/feldspathoid conflict and triangle basis. Shared boundaries and overlaps retained; polygons must be simple non-self-intersecting. Caller independently establishes matching units, evidence, method edition and applicability; output is not compliance, diagnosis, work-safety approval, geological identity or validated hazard prediction.
Geology Radiocarbon Calibration Calculator Invert independently verified matching calibration curve retaining all piecewise-linear crossings/plateau sample coordinates; no unique calibrated date or probability posterior. Caller independently establishes matching units, evidence, method edition and applicability; output is not compliance, diagnosis, work-safety approval, geological identity or validated hazard prediction.
Geology Rayleigh Fractionation Calculator Ideal Rayleigh fractional-crystallization residual liquid C=C0F^(D−1), independently constant bulk Dand actual remaining melt fraction. Not closed equilibrium melting, cumulate average or fitted actual petrogenesis.
Geology Rb Sr Initial Ratio Calculator Declared closed-system initial87Sr/86Srat independently established age, subtract87Rb/86Sr(expλt−1). Not fit isochron age, initial reservoir or open-system correction; negative inferred residual retained for inconsistent data.
Geology Rb Sr Isochron Calculator Fit a two-point Rb-Sr isochron and convert its slope to an age using the Rb-87 decay constant.
Geology Re Os Isochron Age Calculator Fit actual Re187/Os188–Os187/Os188 array and named decay inversion, common initial Os/closed system independently assumed. Caller independently establishes matching units, evidence, method edition and applicability; output is not compliance, diagnosis, work-safety approval, geological identity or validated hazard prediction.
Geology Ree Pattern Slope La Yb Calculator Actual reference-normalized La/Ybend-member slope indicator using caller independently matched normalization source/edition; not whole REEpattern, slope-per-atomic-number or existing Eu/Ceanomaly.
Geology Sand Control Gravel Pack Permeability Calculator Exact caller independently verified Geology Sand Control Gravel Pack Permeability Calculator reference lookup. Required actual context: actual gravel pack permeability under grain distribution, porosity, fines, compaction and fluid state; no incomplete inputs silently determine a universal predictive number. Illustrative records are not authoritative data. No universal material coefficient, law, norm, medical limit, diagnosis, clinical dose, work-safety approval, engineering design or guaranteed forecast is inferred. This operation retrieves actual qualified reference text; it does not calculate a missing physical model or verify the truth of supplied evidence.
Geology Seismic B Value From Catalog Calculator Declared discrete-bin AkiMLEb=log10(e)/(meanM−(Mc−ΔM/2)), complete actual catalog above independently verified Mc. Declustering, completeness, bin origin and uncertainty external; not fault recurrence forecast.
Geology Seismic Magnitude From Fault Length Calculator Conditional independently matched piecewise-linear independently calibrated fault-length/magnitude relation for actual fault type and rupture definition reference interpolation. Strictly increasing verifiedRuptureLengthKmKnots and aligned same-unit verifiedMagnitudeKnots required, no extrapolation. Examples are illustrative knots, not verified normative data; actual calibration, branch selection, uncertainty and applicability external. Not automatic parameter fitting, physical identity, clinical recommendation or a validated hazard forecast.
Geology Seismic Recurrence Interval Calculator Actual ordered qualifying seismic event intervals and mean, not probabilistic recurrence return period from a missing catalog or next-earthquake prediction.
Geology Seismic Stress Drop Calculator Circular crack7M0/(16r³) from independent rupture radius, not moment-magnitude conversion or forecast. Caller independently establishes matching units, evidence, method edition and applicability; output is not compliance, diagnosis, work-safety approval, geological identity or validated hazard prediction.
Geology Shale Gouge Ratio Sgr Calculator Declared SGRsum shale fraction×actual faulted interval thickness/faultthrow. Complete actual displaced stratigraphy required; no assume sealing, pore pressure or a hydrocarbon column.
Geology Shale Smear Factor Ssf Calculator SSF throw/source-bed thickness separately for mapped shale beds; no predicted smear continuity or seal threshold. Caller independently establishes matching units, evidence, method edition and applicability; output is not compliance, diagnosis, work-safety approval, geological identity or validated hazard prediction.
Geology Skewness Folk Ward Calculator Folk–Ward normalized central and tail PHI asymmetry, not moment skew. Caller independently establishes matching units, evidence, method edition and applicability; output is not compliance, diagnosis, work-safety approval, geological identity or validated hazard prediction.
Geology Sm Nd Isochron Calculator Fit a two-point Sm-Nd isochron and convert its slope to an age using the Sm-147 decay constant.
Geology Sorting Coefficient Folk Ward Calculator Folk–Ward inclusive graphic PHI sorting, not Trask diameter quartiles. Caller independently establishes matching units, evidence, method edition and applicability; output is not compliance, diagnosis, work-safety approval, geological identity or validated hazard prediction.
Geology Sorting Coefficient Trask Calculator Trask√(D75/D25), ascending cumulative-percent-finer diameter quantiles. Caller independently establishes matching units, evidence, method edition and applicability; output is not compliance, diagnosis, work-safety approval, geological identity or validated hazard prediction.
Geology Specific Yield Gravity Drainage Calculator Evaporation-corrected actual gravity drainage experiments, not total porosity or elastic storativity. Caller independently establishes matching units, evidence, method edition and applicability; output is not compliance, diagnosis, work-safety approval, geological identity or validated hazard prediction.
Geology Sr Anomaly Calculator Declared Sranomaly SrN/sqrt(CeN×NdN), not silently linear interpolation or Prneighbor convention. Same independently verified normalization reference required; not infer mineral source/age.
Geology Stable Isotope Delta Calculator Convert sample and standard isotope ratios into delta notation in permil relative to the standard.
Geology Storativity Pumping Test Jacob Calculator Jacob 2.25Tt0/r² from independently fitted late-time intercept, not thickness×specific-storage. Caller independently establishes matching units, evidence, method edition and applicability; output is not compliance, diagnosis, work-safety approval, geological identity or validated hazard prediction.
Geology Strontium Isotope Ratio Calculator Correct a measured 87Sr/86Sr ratio for instrumental mass bias by exponential-law normalization to 88Sr/86Sr = 8.375209.
Geology Subduction Slab Dip Calculator Actual slab segment depth/horizontal projection dip, not total subduction geometry or infer earthquakes from angle.
Geology Subsidence Bowl Volume Calculator Exact integral2πr×piecewise-linear measured subsidence profile, explicit axisymmetry and observed zero edge; unlike depth×footprint. Caller independently establishes matching units, evidence, method edition and applicability; output is not compliance, diagnosis, work-safety approval, geological identity or validated hazard prediction.
Geology Tailings Dam Factor Of Safety Calculator Exact caller independently verified Geology Tailings Dam Factor Of Safety Calculator reference lookup. Required actual context: tailings dam stability model, actual stratigraphy, pore pressures, loading, slip surface and independently assessed safety analysis; no incomplete inputs silently determine a universal predictive number. Illustrative records are not authoritative data. No universal material coefficient, law, norm, medical limit, diagnosis, clinical dose, work-safety approval, engineering design or guaranteed forecast is inferred. This operation retrieves actual qualified reference text; it does not calculate a missing physical model or verify the truth of supplied evidence.
Geology TAS Classification Lookup Silica/total-alkali TAS class coordinates, independently verified same-edition polygons, not plotting bands. Shared boundaries and overlaps retained; polygons must be simple non-self-intersecting. Caller independently establishes matching units, evidence, method edition and applicability; output is not compliance, diagnosis, work-safety approval, geological identity or validated hazard prediction.
Geology Tephra Fall Thickness Exponential Decay Calculator Declared fitted one-dimensional exponential tephra thicknessT0exp(−x/L). Actual applicable transect and independently fit T0, Lrequired; no eruption forecast, total volume or fallout hazard approval.
Geology Th U Ratio Calculator Actual same-basis thorium/uranium ratio, not radioactive age or equilibrium decay status. Actual independently matched quantities/units required; not infer causal effect, clinical guidance or safe design.
Geology Thermoluminescence Age Calculator thermoluminescence actual equivalent-dose/dose-rate age under independently resolved fading, uptake, water and saturation assumptions. Actual independently matched quantities/units required; not infer causal effect, clinical guidance or safe design.
Geology Ti In Quartz Thermometer Titaniq Calculator Conditional independently matched piecewise-linear actual TitaniQthermometry at fixed pressure and titania activity reference interpolation. Strictly increasing verifiedTitaniumPpmKnots and aligned same-unit verifiedTemperatureKelvinKnots required, no extrapolation. Examples are illustrative knots, not verified normative data; actual calibration, branch selection, uncertainty and applicability external. Not automatic parameter fitting, physical identity, clinical recommendation or a validated hazard forecast.
Geology Ti In Zircon Thermometer Calculator Conditional independently matched piecewise-linear actual Ti-in-zircon thermometry at fixed pressure and silica/titania activities reference interpolation. Strictly increasing verifiedTitaniumPpmKnots and aligned same-unit verifiedTemperatureKelvinKnots required, no extrapolation. Examples are illustrative knots, not verified normative data; actual calibration, branch selection, uncertainty and applicability external. Not automatic parameter fitting, physical identity, clinical recommendation or a validated hazard forecast.
Geology Trace Element Ratio Calculator Actual named trace-element concentration ratio on same chemical/massbasis. Actual independently matched quantities/units required; not infer causal effect, clinical guidance or safe design.
Geology Transmissivity Pumping Test Jacob Calculator FIT raw independently qualified late-time pumping time/drawdown; not existing supplied Cooper–Jacob slope formula. Caller independently establishes matching units, evidence, method edition and applicability; output is not compliance, diagnosis, work-safety approval, geological identity or validated hazard prediction.
Geology Tritium Age Calculator Date groundwater from the decay of initial to measured tritium activity using a 12.32-year half-life.
Geology Tsunami Run Up Height Calculator Exact caller independently verified Geology Tsunami Run Up Height Calculator reference lookup. Required actual context: actual tsunami runup site/topography, waveform, nearshore transformation and independently validated hydrodynamic model; no incomplete inputs silently determine a universal predictive number. Illustrative records are not authoritative data. No universal material coefficient, law, norm, medical limit, diagnosis, clinical dose, work-safety approval, engineering design or guaranteed forecast is inferred. This operation retrieves actual qualified reference text; it does not calculate a missing physical model or verify the truth of supplied evidence.
Geology Two Feldspar Geothermometer Calculator Conditional independently matched piecewise-linear actual two-feldspar geothermometer calibration at matched pressure/activities reference interpolation. Strictly increasing verifiedExchangeCoordinateKnots and aligned same-unit verifiedTemperatureKelvinKnots required, no extrapolation. Examples are illustrative knots, not verified normative data; actual calibration, branch selection, uncertainty and applicability external. Not automatic parameter fitting, physical identity, clinical recommendation or a validated hazard forecast.
Geology U Pb Concordia Calculator Convert 206Pb/238U and 207Pb/235U ratios into concordia-style ages in Ma and their percent discordance.
Geology U Pb Discordia Upper Intercept Calculator Actual discordia regression intersected with independently matched piecewise-linear concordia, all witnesses and upper observed intercept retained; not extrapolated older geological event. Caller independently establishes matching units, evidence, method edition and applicability; output is not compliance, diagnosis, work-safety approval, geological identity or validated hazard prediction.
Geology U Th Disequilibrium Age Calculator U–Th disequilibrium inversion of independently solved matching initialU234/detritalTh/decay closed-system candidate activity curve, all roots retained; no secular-equilibrium shortcut. Caller independently establishes matching units, evidence, method edition and applicability; output is not compliance, diagnosis, work-safety approval, geological identity or validated hazard prediction.
Geology U Th He Age Calculator Exact caller independently verified Geology U Th He Age Calculator reference lookup. Required actual context: actual U-Th-Heage helium production/parent history, alpharetention, thermal diffusion and isotope/decay conventions; no incomplete inputs silently determine a universal predictive number. Illustrative records are not authoritative data. No universal material coefficient, law, norm, medical limit, diagnosis, clinical dose, work-safety approval, engineering design or guaranteed forecast is inferred. This operation retrieves actual qualified reference text; it does not calculate a missing physical model or verify the truth of supplied evidence.
Geology Varve Thickness Calculator Actual sediment boundary intervals divided by independently verified annual lamina counts; annuality not inferred from visible banding. Caller independently establishes matching units, evidence, method edition and applicability; output is not compliance, diagnosis, work-safety approval, geological identity or validated hazard prediction.
Geology Vitrinite Reflectance Ro Calculator Actual standard-calibrated reflected intensities for independently identified vitrinite in same optical medium; no maturation identity or universal grade. Caller independently establishes matching units, evidence, method edition and applicability; output is not compliance, diagnosis, work-safety approval, geological identity or validated hazard prediction.
Geology Vitrinite Reflectance To Temperature Calculator Conditional independently matched piecewise-linear actual vitrinite maximum temperature calibration with maturity/heating-history context reference interpolation. Strictly increasing verifiedReflectancePercentKnots and aligned same-unit verifiedTemperatureKelvinKnots required, no extrapolation. Examples are illustrative knots, not verified normative data; actual calibration, branch selection, uncertainty and applicability external. Not automatic parameter fitting, physical identity, clinical recommendation or a validated hazard forecast.
Geology Wentworth Grain Size Phi Calculator Actual weighted grain distribution phi=−log2(d/mm), signed coarse coordinates retained. Caller independently establishes matching units, evidence, method edition and applicability; output is not compliance, diagnosis, work-safety approval, geological identity or validated hazard prediction.
Geology Wentworth Phi To Mm Calculator Invert phi BIN intervals to diameter intervals, decreasing mapping reverses bounds; not arithmetic mean diameter from inverted mean phi. Caller independently establishes matching units, evidence, method edition and applicability; output is not compliance, diagnosis, work-safety approval, geological identity or validated hazard prediction.
Geology Zircon Age Calculator Exact caller independently verified Geology Zircon Age Calculator reference lookup. Required actual context: actual zircon U-Pbsystem/isotope ratio, decay constants, common-Pb correction, concordance, uncertainty and independently verified age-model edition; no infer a unique zircon age from elemental uranium alone. Illustrative records are not authoritative data. No universal material coefficient, law, norm, medical limit, diagnosis, clinical dose, work-safety approval, engineering design or guaranteed forecast is inferred. This operation retrieves actual qualified reference text; it does not calculate a missing physical model or verify the truth of supplied evidence.
Geology Zircon Saturation Temperature Watson Harrison Calculator Watson–Harrison 1983 zircon saturation T=12900/(ln(497644/Zr)+2.95+.85(M−1)); M is independently calculated cation(Na+K+2Ca)/(AlSi), melt saturation/application externally verified. Caller independently establishes matching units, evidence, method edition and applicability; output is not compliance, diagnosis, work-safety approval, geological identity or validated hazard prediction.
Geology Zr In Rutile Thermometer Calculator Conditional independently matched piecewise-linear actual Zr-in-rutile thermometry at fixed pressure/phase activities reference interpolation. Strictly increasing verifiedZirconiumPpmKnots and aligned same-unit verifiedTemperatureKelvinKnots required, no extrapolation. Examples are illustrative knots, not verified normative data; actual calibration, branch selection, uncertainty and applicability external. Not automatic parameter fitting, physical identity, clinical recommendation or a validated hazard forecast.
Gravity Anomaly Bouguer Calculator Land Bouguer anomaly in milligal: g_obs - g_ref + 0.3086 h - 2 pi G rho h, with elevation h in meters and reduction density rho in kilograms per cubic meter (default 2670 kg/m^3).
Gravity Anomaly Free Air Calculator Land free-air anomaly in milligal: g_obs - g_ref + 0.3086 h with station elevation h in meters and the standard free-air gradient of 0.3086 milligal per meter.
Gutenberg Richter B Value Calculator Aki (1965) maximum-likelihood b value of the Gutenberg-Richter law log10 N = a - bM: b = log10(e) / (mean magnitude - completeness magnitude).
Harker Diagram Silica Calculator Prepare one silica-versus-oxide point pair for a Harker variation diagram.
Hazen Grain Size D10 Calculator Invert the Hazen formula K = C * D10^2 to estimate the effective grain size D10 in centimeters from hydraulic conductivity in cm/s and the Hazen coefficient in 1/(cm*s).
Helium Diffusion Closure Temperature Calculator Solve the Dodson (1973) closure temperature for helium diffusion given activation energy, diffusion anisotropy and cooling rate.
Hoek Brown Criterion Calculator Generalized Hoek-Brown peak strength sigma_1 = sigma_3 + sigma_ci*(m_b*sigma_3/sigma_ci + s)^a with m_b, s and a from GSI and the disturbance factor D (Hoek et al., 2002).
Hole Cleaning Efficiency Calculator Compute the annular velocity, cuttings transport velocity and hole cleaning efficiency from circulation rate, well geometry and cuttings slip velocity.
Hydraulic Conductivity From Permeability Calculator Convert intrinsic permeability in square meters to hydraulic conductivity in meters per second via K = k * rho * g / mu (defaults for water at 20 degrees Celsius).
Hydraulic Gradient Calculator Compute the hydraulic gradient as head loss in meters divided by the flow path length in meters.
Hydrostatic Pressure Gradient Brine Calculator Compute the hydrostatic pressure gradient of a brine column from its density and local gravity.
Isochore Thickness Calculator Vertical (isochore) thickness from true stratigraphic thickness and dip: T = t / cos(dip).
Isopach Thickness Calculator True stratigraphic thickness (isopach) measured perpendicular to bedding from a vertical thickness: t = T * cos(dip).
Jacob Drawdown Calculator Compute the Cooper-Jacob straight-line approximation of drawdown in meters from discharge (m3/day), transmissivity (m2/day), radial distance (m), storativity and time (days).
Kick Tolerance Calculator Compute the maximum kick volume that can be shut in without fracturing the formation at the casing shoe.
Lava Viscosity Calculator Arrhenius melt viscosity eta = eta0 * exp(Ea / (R T)) with Ea in J/mol, eta0 in pascal seconds and T in kelvin.
Leak Off Test Formation Strength Calculator Convert a surface leak-off test pressure into formation strength at the shoe, its fracture gradient and equivalent mud density.
Magma Density Calculator Bulk magma density as the volume-weighted mixture of melt and suspended crystals: rho = rho_melt (1 - phi) + rho_crystals phi.
Magnetic Anomaly Total Field Calculator Total-field magnetic anomaly in nanotesla: the difference between the observed total-field magnitude and the regional (main-field) magnitude at the same location.
Magnetic Susceptibility Lookup Determine the dimensionless volume magnetic susceptibility chi = M / H (SI) from an induced magnetization in amperes per meter and a magnetizing field strength in amperes per meter, and convert it to CGS electromagnetic units (chi_cgs = chi_SI / 4 pi). A negative value indicates diamagnetic behavior.
Material Balance Gas Initially In Place Calculator Estimate the volumetric gas initially in place from pore volume and the real-gas formation volume factor Bg at standard conditions of 101325 Pa and 288.15 K.
Material Balance Oil Initially In Place Calculator Estimate the volumetric oil initially in place from drainage area, net thickness, porosity, water saturation and oil formation volume factor.
Mg Number Vs Silica Calculator Compute the molar Mg number (100*Mg/(Mg+Fe)) with ferric iron converted to ferrous, paired with SiO2 for differentiation-trend plots.
Mineral Cleavage Lookup Look up the number of cleavage directions and their quality/geometry for a common mineral.
Mineral Density Lookup Look up the typical room-temperature grain density in g/cm3 for a common rock-forming or ore mineral.
Mineral Luster Lookup Look up the typical luster (quality of surface light reflection) of a common mineral.
Mineral Streak Lookup Look up the characteristic color of a mineral's powder as it would appear on a streak plate.
Modulus Of Volume Compressibility Calculator Oedometric (constrained) modulus E_oed = (1 + e0) * d_sigma' / de = 1 / mv from a consolidation loading increment. Void ratios dimensionless, stresses in kPa.
Mohr Circle Center Calculator Center of the Mohr circle for two principal stresses: sigma_center = (sigma_1 + sigma_3) / 2 on the normal-stress axis.
Mohr Circle Radius Calculator Radius of the Mohr circle for two principal stresses: R = (sigma_1 - sigma_3) / 2, also the maximum shear stress.
Mohr Coulomb Shear Strength Calculator Mohr-Coulomb shear strength tau_f = c' + sigma_n' * tan(phi') for given effective normal stress, cohesion and friction angle.
Mohs Hardness Lookup Look up the Mohs scratch hardness on the classic 1-to-10 reference scale for a named mineral.
Moment Magnitude Calculator Hanks-Kanamori moment magnitude Mw = (2/3)(log10 M0 - 9.1) with seismic moment M0 in newton meters.
Mud Weight Required Calculator Determine the mud density needed to balance a known pore pressure at depth, including an optional trip margin.
Nodal Analysis Inflow Performance Calculator Compute Vogel (1968) inflow performance for a saturated oil well from reservoir pressure, flowing bottom-hole pressure and productivity index.
Nodal Analysis Outflow Performance Calculator Compute the single-phase outflow (tubing intake) bottom-hole pressure required to lift a given liquid rate against wellhead pressure, hydrostatic head and Darcy-Weisbach friction.
Oil Density Calculator Convert API gravity to crude oil specific gravity and density in kg/m3.
Oil Formation Volume Factor Calculator Compute the saturated oil formation volume factor Bo with the Standing (1947) correlation.
Oil Viscosity Beggs Robinson Calculator Compute dead and live oil viscosity with the Beggs-Robinson (1975) correlations.
Onlap Angle Calculator Angle between dipping strata and the inclined older surface they progressively onlap: |dip(strata) - dip(substrate)|, assuming comparable dip directions.
Overburden Gradient Calculator Compute the vertical overburden stress gradient Sv = rho_bulk * g from average bulk density.
Overburden Stress Calculator Compute the geostatic (overburden) vertical stress as the product of unit weight in kN/m3 and depth in meters, giving kPa.
Overconsolidation Ratio Calculator Overconsolidation ratio OCR = sigma_p' / sigma_v0' where sigma_p' is the maximum past effective vertical stress (preconsolidation pressure) and sigma_v0' the present effective overburden stress, both in kPa.
Parasequence Thickness Calculator Mean parasequence thickness from the measured thickness of a parasequence set divided by its number of parasequences.
Passive Earth Pressure Calculator Rankine passive lateral earth pressure sigma_p = Kp * gamma * z at a given depth in front of a vertical wall with a level backfill.
Passive Earth Pressure Coefficient Calculator Rankine passive earth pressure coefficient Kp = (1 + sin phi) / (1 - sin phi) for a vertical wall and level backfill.
Pore Pressure Prediction Eaton Resistivity Calculator Predict formation pore pressure from shale resistivities with the Eaton resistivity method.
Pore Pressure Prediction Eaton Sonic Calculator Predict formation pore pressure from compressional sonic travel times with the Eaton sonic method.
Pore Water Pressure Calculator Compute hydrostatic pore water pressure in kilopascals as unit weight of water times the height of the water column above the point.
Porosity From Bulk Density Calculator Compute porosity as n = 1 - (bulk density / grain density) for a rock or soil sample.
Porosity From Void Ratio Calculator Convert void ratio e to porosity using n = e / (1 + e).
Preconsolidation Pressure Calculator Maximum past effective vertical stress sigma_p' = OCR * sigma_v0' from the definition of the overconsolidation ratio. Stresses in kPa; use a Casagrande construction on the oedometer curve for direct measurement.
Q System Rating Calculator NGI rock mass quality Q = (RQD/Jn) * (Jr/Ja) * (Jw/SRF) from the six Barton parameters supplied directly.
QAPF Plot Calculator Normalize modal quartz, alkali feldspar, plagioclase and feldspathoid contents to QAPF coordinates and pick the plotting triangle.
Rate Of Penetration Calculator Compute drilling rate of penetration in metres per hour from drilled length and elapsed time.
Recompression Index Calculator Recompression (swell/reload) index Cr = Cs = (e1 - e2) / log10(sigma2' / sigma1') measured on an unload-reload loop of an oedometer test. Void ratios dimensionless, effective stresses in kPa.
Recovery Factor Calculator Compute the recovery factor as cumulative produced volume divided by original oil in place.
Recovery Residual Drawdown Calculator Compute Theis recovery residual drawdown in meters as Q / (4 pi T) times the natural log of pumping duration over time since recovery began (days).
REE Anomaly Ce Calculator Compute the chondrite- or PAAS-normalized cerium anomaly Ce/Ce* from La, Ce and Pr concentrations.
REE Anomaly Eu Calculator Compute the chondrite- or PAAS-normalized europium anomaly Eu/Eu* from Sm, Eu and Gd concentrations.
REE Normalization Calculator Normalize rare earth element concentrations to chondrite or PAAS and report Ce and Eu anomalies.
Relative Permeability Gas Oil Calculator Compute Corey gas-oil relative permeabilities from gas saturation with residual saturations, Corey exponents and endpoint values.
Relative Permeability Oil Water Calculator Compute Corey oil-water relative permeabilities from saturation with residual saturations, Corey exponents and endpoint values.
Reserve Recoverable Calculator Compute recoverable reserves as original oil in place multiplied by the recovery factor.
Richter Magnitude From Amplitude Calculator Original Richter (1935) local magnitude ML = log10(A / A0), comparing maximum Wood-Anderson trace amplitude in millimeters with the zero-magnitude reference amplitude at the same epicentral distance (0.001 mm at 100 km by definition).
Rock Density Lookup Look up the typical dry bulk density range in g/cm3 for a common rock type.
Rock Mass Rating RMR Calculator Bieniawski RMR total from the five sub-ratings (strength max 15, RQD max 20, spacing max 20, groundwater max 15, joint condition max 30) with the standard RMR class boundaries.
Rock Porosity Calculator Compute the porosity fraction and percentage of a rock sample from its pore volume and bulk volume.
Rock Quality Designation RQD Calculator Rock Quality Designation RQD = 100 * (sum of intact core pieces at least 10 cm long) / total drilled core run length.
S-P Interval To Distance Calculator Epicentral distance from the S-minus-P arrival-time interval: d = dt * (vP * vS) / (vP - vS) for a common straight-ray path.
Saturated Density Calculator Compute the saturated bulk density from specific gravity and void ratio using rho_sat = (Gs + e) / (1 + e) * rho_w.
Secondary Compression Settlement Calculator Secondary (creep) settlement Ss = H * C_alpha / (1 + e_p) * log10(t2 / t1), where C_alpha is the secondary compression index from the e - log10 t tail of an oedometer test, e_p the void ratio at end of primary consolidation, and t1, t2 the creep time window in years.
Sedimentation Rate Calculator Average sedimentation (accumulation) rate from compacted sediment thickness divided by deposition time; reported in m/Myr and cm/kyr.
Seismic Acoustic Impedance Calculator Acoustic impedance Z = rho Vp from P-wave velocity in meters per second and bulk density in kilograms per cubic meter, returned in pascal seconds per meter.
Seismic Energy Calculator Gutenberg-Richter energy relation log10 E = 1.5 M + 4.8 with E in joules, also expressed in tons of TNT (4.184e9 joules per ton).
Seismic Intensity MMI Lookup Look up the Modified Mercalli intensity (I-XII) shaking name and typical effects for a given integer intensity level.
Seismic Interval Velocity Dix Calculator Dix (1955) interval velocity Vint^2 = (Vrms2^2 t2 - Vrms1^2 t1) / (t2 - t1) from RMS velocities in meters per second and zero-offset two-way times in seconds.
Seismic Migration Aperture Calculator Horizontal migration aperture for a dipping reflector: z tan(dip) per side (and twice that for the full aperture), with reflector depth z in meters and dip angle in degrees.
Seismic Moment Calculator Seismic moment M0 = mu * A * D with rigidity in pascals, rupture area in square meters and average slip in meters; result in newton meters.
Seismic NMO Correction Calculator Normal-moveout hyperbola t(x)^2 = t0^2 + x^2/V^2 for a horizontal reflector, with zero-offset time t0 in seconds, source-receiver offset x in meters and velocity in meters per second.
Seismic Reflection Coefficient Calculator Normal-incidence P-wave reflection coefficient R = (Z2 - Z1) / (Z2 + Z1) from layer velocities in meters per second and bulk densities in kilograms per cubic meter, where Z is acoustic impedance.
Seismic Resolution Horizontal Fresnel Zone Calculator First Fresnel zone radius r = (V/2) sqrt(t0 / f) governing horizontal seismic resolution, with velocity in meters per second, zero-offset two-way time t0 in seconds and dominant frequency f in hertz.
Seismic Resolution Vertical Calculator Vertical (Rayleigh/Widess) resolution as one quarter of the dominant wavelength lambda = V / f, with velocity in meters per second and dominant frequency in hertz; two features closer than this cannot be separated in time.
Seismic Rms Velocity Calculator Layer-root-mean-square velocity Vrms^2 = sum(Vi^2 ti) / sum(ti) from per-layer velocities in meters per second and one-way interval travel times in seconds.
Seismic Stack Velocity Calculator Invert the normal-moveout hyperbola t(x)^2 = t0^2 + x^2/Vstk^2 for the stacking velocity in meters per second, given a zero-offset time in seconds and an observed arrival time in seconds at a source-receiver offset in meters.
Seismic Two Way Time Calculator Convert depth to seismic travel time: t = z / V for the one-way time and twice that for the zero-offset two-way time, with depth in meters and interval velocity in meters per second.
Sequence Boundary Lookup Assess how strongly an observed stratigraphic feature indicates a sequence boundary, and on which side of the surface it occurs.
Shelf Edge Trajectory Angle Calculator Shelf-edge trajectory angle from vertical rise and horizontal run of shelf-edge migration: atan2(rise, run). Positive angles are aggradational, negative retrogradational.
Shrinkage Limit Calculator Compute the shrinkage limit SL in percent from the initial water content (percent), wet and dry pat volumes (cm3), oven-dry mass (g) and water density (g/cm3).
Shrinkage Ratio Calculator Compute soil shrinkage ratio as oven-dry density divided by water density, and shrinkage limit from the mass and volume lost while drying.
Slope Stability Factor Of Safety Bishop Calculator Bishop simplified method of slices with uniform slice width and pore pressure ratio ru: FS solves FS = sum[(c'b + W(1-ru)tan(phi'))/m_alpha] / sum[W sin(alpha)] with m_alpha = cos(alpha) + tan(phi')sin(alpha)/FS.
Slope Stability Factor Of Safety Infinite Slope Calculator Factor of safety of an infinite slope with a planar failure plane parallel to the slope at depth z: FS = (c' + gamma*z*cos^2(beta)*(1-ru)*tan(phi')) / (gamma*z*sin(beta)*cos(beta)).
Solution Gas Oil Ratio Calculator Compute the saturated solution gas-oil ratio Rs with the Standing (1947) correlation.
Specific Gravity Calculator Compute the specific gravity of soil or rock solids as the ratio of particle density to water density.
Spider Diagram Normalization Calculator Normalize incompatible-trace-element concentrations to the Sun and McDonough (1989) primitive mantle for spider diagrams.
Storativity Confined Calculator Compute confined-aquifer storativity as saturated thickness in meters times specific storage in reciprocal meters.
Storativity Unconfined Calculator Compute unconfined-aquifer storativity as specific yield plus the elastic storage term of saturated thickness times specific storage.
Stratal Termination Type Lookup Classify a seismic/stratigraphic stratal termination (onlap, downlap, toplap, truncation, concordance) by its contact position and process meaning.
Stratigraphic Thickness True Vs Apparent Calculator For a bed cropped out over width w perpendicular to strike on horizontal ground: true thickness t = w sin(delta) and vertical (apparent) thickness t_v = w tan(delta), with dip delta in degrees.
Strike Dip To Dip Direction Calculator Convert strike azimuth and handedness to dip direction, which is perpendicular to strike (right-hand rule adds 90 degrees).
Subsidence Rate Calculator Average tectonic-plus-loaded subsidence rate over an interval: amount divided by duration.
Swell Index Calculator Free swell index of a clay per IS 2720 Part 40: (V_water - V_kerosene) / V_kerosene * 100, comparing equilibrium volumes of equal dry specimens in distilled water versus kerosene. Volumes in mL.
Systems Tract Lookup Look up the cycle position, base-level trend, and bounding surfaces of a depositional systems tract within a stratigraphic sequence.
TAS Diagram Plot Calculator Prepare total-alkalis versus silica coordinates and the Le Bas silica band for plotting on the IUGS TAS diagram.
Theis Drawdown Calculator Compute Theis non-equilibrium drawdown in meters from discharge (m3/day), transmissivity (m2/day), radial distance (m), storativity and elapsed time (days).
Time Factor Consolidation Calculator Terzaghi time factor Tv = cv * t / Hd^2, where cv is the coefficient of consolidation in m2/year, t the elapsed time since loading in years, and Hd the longest drainage path in m (half the layer thickness for double drainage).
Toplap Angle Calculator Angle between initially inclined strata and the nearly horizontal upper surface beneath which they toplap: |dip(strata) - dip(upper surface)|, assuming comparable dip directions.
Transmissivity Calculator Compute aquifer transmissivity in square meters per second as hydraulic conductivity times saturated aquifer thickness.
Travel Time P Wave Calculator Straight-ray P-wave first-arrival time t = d / vP with distance and velocity in kilometers and kilometers per second.
Travel Time S Wave Calculator Straight-ray S-wave arrival time t = d / vS with distance and velocity in kilometers and kilometers per second.
True Thickness From Apparent Calculator Convert an apparent thickness measured on a vertical traverse to true bed thickness: t_true = t_apparent * cos(theta), where theta is the angle between the traverse and the dip direction.
Unconformity Angle Calculator Angular discordance across an unconformity: the absolute difference between dip of beds above and dip of beds below, assuming comparable dip directions.
Uniformity Coefficient Calculator Compute the uniformity coefficient Cu = D60 / D10 from grain sizes in millimeters read from a gradation curve.
VEI Lookup Newhall-Self (1982) Volcanic Explosivity Index lookup: classification name and lower-bound bulk ejecta volume for each VEI from 0 to 8; VEI 0 is below 10^4 cubic meters.
Void Ratio Calculator Compute the soil or rock void ratio e = Vv / Vs from the volumes of voids and solid particles.
Void Ratio From Porosity Calculator Convert porosity n to the void ratio using e = n / (1 - n).
Volcanic Explosivity Index Calculator Assign a Newhall-Self Volcanic Explosivity Index from bulk ejecta volume in cubic meters, including the non-log-uniform VEI 0, 1, and 2 volume thresholds.
Water Content Calculator Compute gravimetric water content as the mass of pore water divided by the oven-dry solids mass, in percent.
Water Cut Calculator Compute the water cut of a producing well as the water fraction of the total liquid flow.
Water Loaded Subsidence Calculator Water-loaded tectonic subsidence after removing the sediment load and replacing it with water: Y = S(rho_m - rho_s)/(rho_m - rho_w) - Wd.
Water Oil Ratio Calculator Compute the producing water-oil ratio as produced water volume divided by produced oil volume.
Well Log Gamma Ray Index Calculator Linear gamma-ray index IGR = (GR - GR_clean) / (GR_shale - GR_clean) from log readings in API units; the standard first step toward Larionov-style Vshale estimates.
Well Log Permeability Wyllie Rose Calculator Estimate permeability in millidarcies from porosity and irreducible water saturation with the Wyllie-Rose power-law relation.
Well Log Porosity Density Calculator Density-log porosity phi_D = (rho_ma - rho_b) / (rho_ma - rho_f) from bulk, matrix and pore-fluid densities in kilograms per cubic meter; the standard formation-density porosity relation.
Well Log Porosity Neutron Calculator Correct a neutron porosity log reading (limestone porosity units) for shale content using V_shale times the shale neutron reading.
Well Log Porosity Sonic Wyllie Calculator Apply the Wyllie time-average equation to a compressional sonic log, with optional shale correction, using slownesses in microseconds per metre.
Well Log Rxo Porosity Calculator Invert the Archie equation in the flushed zone to estimate porosity from Rxo and mud-filtrate resistivity.
Well Log Shale Volume Calculator Convert a gamma ray reading in API units to shale volume using the linear or Larionov transforms.
Well Log Water Saturation Archie Calculator Invert the Archie equation for water saturation from true resistivity, formation water resistivity and porosity.
Well Log Water Saturation Simandoux Calculator Solve the Simandoux shaly-sand equation for water saturation including shale-conductivity correction.
Wellhead Pressure Shut In Calculator Compute the shut-in wellhead (tubing head) pressure by subtracting the static hydrostatic column from the shut-in bottom-hole pressure.