Cheat sheet
ASBOG FG/PG Cheat Sheet
General & Field Geology
- 17% of exam
- FG 17% PG 17% Relative Dating Principles Time + Unconformities Field methods Geologic maps
Mineralogy, Petrology & Geochemistry
- 5-12% of exam
- FG 12% PG 5% Mineral ID Properties Silicates + Rock Cycle Bowen's series Metamorphic grade
Sedimentology, Stratigraphy & Paleontology
- 5-11% of exam
- FG 11% PG 5% Deposition + Facies Stratigraphy + Fossils Sequence stratigraphy Index fossils
Geomorphology, Surficial & Quaternary
- 8-14% of exam
- FG 14% PG 8% Fluvial + Slopes Glacial + Weathering Mass wasting Landforms
Structure, Tectonics & Seismology
- 9-12% of exam
- FG 12% PG 9% Stress, Faults, Folds Deformation + Tectonics Strike + dip Plate boundaries
Hydrogeology
- 13-22% of exam
- FG 13% PG 22% Darcy + Aquifer Properties Wells + Groundwater Darcy's law Confined vs unconfined
Engineering Geology
- 12-18% of exam
- FG 12% PG 18% Soil + Rock Mechanics Hazards + Slope Failures Effective stress Liquefaction
Economic Geology & Energy
- 9-16% of exam
- FG 9% PG 16% Ore Deposits Energy + Mining Porphyry copper Resource vs reserve
Quick Facts
- FG Exam 140 MCQ, 4 hours
- PG Exam 110 MCQ, 4 hours
- Pass Scaled score 70
- Domains 8 content areas
- Format Computer-based (Prometric)
- Base exam fee $200 FG + $250 PG
- Seat fee per part Handbook $75; registration $78; confirm checkout
- Eligibility State board approval
Geologic Periods GE
- Camels Often Sit Down Carefully Perhaps Their Joints Creak
- Cambrian, Ordovician Silurian, Devonian Carboniferous, Permian Triassic, Jurassic Cretaceous
Date the Rocks GE
- Order undeformed beds → Superposition ( Relative )
- Dike cuts unit → Cross-cutting ( Younger cutter )
- Fragment in rock → Inclusions ( Clast older )
- Correlate distant strata → Faunal succession
- Need numeric age → Radiometric dating ( Absolute )
Relative Dating Principles GE
- Superposition Lower beds are older
- Original horizontality Layers deposit flat
- Cross-cutting Cutter is younger
- Inclusions Fragments predate host
- Faunal succession Fossils in fixed order
- Uniformitarianism Present interprets past
Time + Unconformities GE
- Time hierarchy Eon, era, period, epoch
- Phanerozoic Paleozoic, Mesozoic, Cenozoic
- Precambrian Hadean, Archean, Proterozoic
- Disconformity Gap, parallel beds
- Angular unconformity Tilted beds below
- Nonconformity Strata over basement
- Paraconformity Hidden time gap
Bowen Discontinuous Series MI
- Olivine → Pyroxene → Amphibole → Biotite
- Olivine: highest temp Pyroxene: single chain Amphibole: double chain Biotite: sheet mica Mafic weathers first
Mineral ID Properties MI
- Mohs hardness 1 talc to 10 diamond
- Luster Metallic or nonmetallic
- Cleavage Breaks along planes
- Fracture Breaks irregularly
- Streak Powder color
- Specific gravity Density vs water
- Crystal habit Characteristic crystal shape
Mohs Hardness 1-10 MI
- Toronto Girls Can Flirt And Only Quit To Chase Dwarves
- 1 Talc, 2 Gypsum 3 Calcite, 4 Fluorite 5 Apatite, 6 Orthoclase 7 Quartz, 8 Topaz 9 Corundum, 10 Diamond
Silicates + Rock Cycle MI
- Nesosilicates Isolated tetrahedra (olivine)
- Inosilicates Chains: pyroxene, amphibole
- Phyllosilicates Sheets: micas, clays
- Tectosilicates Frameworks: quartz, feldspar
- Fractional crystallization Melt evolves felsic
- Index minerals Chlorite to sillimanite grade
- Foliation Aligned metamorphic minerals
Deposition + Facies SE
- Walther's law Adjacent facies stack vertically
- Bouma sequence Turbidite Ta to Te
- Cross-bedding Records current direction
- Graded bedding Coarse fines upward
- Transgression Sea level rises
- Regression Sea level falls
Stratigraphy + Fossils SE
- Index fossil Widespread, short-lived
- Biostratigraphy Correlate by fossils
- Lithostratigraphy Correlate by rock
- Sequence boundary Sea-level fall surface
- Maximum flooding surface Peak transgression level
- Facies model Predictive depositional reconstruction
Weathering vs Erosion GE
Weathering
- Breaks in place
- Physical or chemical
- No transport
Erosion
- Removes material
- Water/wind/ice
- Transports away
- Break vs transport
Fluvial + Slopes GE
- Strahler order Stream ranking system
- Drainage density Channel length per area
- Cut bank Outer bend erosion
- Point bar Inner bend deposition
- Angle of repose 30-35° dry sand
- Base level Lowest erosion limit
Glacial + Weathering GE
- Till Unsorted ice deposit
- Stratified drift Sorted meltwater deposit
- Moraine Glacial debris ridge
- Loess Wind-blown silt
- Solifluction Saturated soil creep
- Karst Dissolved carbonate terrain
- Chemical weathering Dissolution, oxidation, hydrolysis
Fault Sense ST
- Normal drops, Reverse raises, Strike-slip slides
- Normal: extension Reverse: compression Strike-slip: shear
Stress vs Strain ST
Stress
- Force per area
- The cause
- Compression/tension/shear
Strain
- Deformation result
- The effect
- Length/shape/volume
- Cause vs effect
Identify the Fault ST
- Hanging wall drops → Normal fault ( Extension )
- Hanging wall rises → Reverse fault ( Compression )
- Low-angle reverse → Thrust fault ( Shortening )
- Horizontal offset → Strike-slip fault ( Shear )
- Fracture, no offset → Joint ( Tension )
Stress, Faults, Folds ST
- Strike Compass bearing of bed
- Dip Steepest slope angle
- Normal fault Hanging wall drops
- Reverse fault Hanging wall rises
- Thrust fault Low-angle reverse fault
- Strike-slip fault Horizontal shear offset
- Anticline Fold arches upward
- Syncline Fold troughs downward
Anticline vs Syncline ST
Anticline
- Arches upward
- Oldest in core
- Convex up
Syncline
- Troughs downward
- Youngest in core
- Concave up
- Old vs young core
Deformation + Tectonics ST
- Stress Force per area
- Strain Resulting deformation
- Brittle Fractures at shallow depth
- Ductile Flows at high P-T
- Divergent Plates spread apart
- Convergent Plates collide, subduct
- Slab pull Dominant plate driver
Darcy's Law HY
- Flow = Conductivity × Area × Gradient
- Q: discharge K: conductivity A: area dh/dl: gradient
Confined vs Unconfined HY
Confined
- Bounded by aquitards
- Under pressure
- Small storativity
Unconfined
- Free water table
- Dewaters pores
- Large specific yield
- Pressure vs water table
Groundwater Tool Picker HY
- Estimate flow rate → Darcy's law
- Aquifer-scale yield → Transmissivity
- Water that drains → Specific yield
- Confined storage → Storativity
- Drawdown over time → Theis solution
- Steady-state well → Thiem equation
- Coastal salt wedge → Ghyben-Herzberg
Darcy + Aquifer Properties HY
- Darcy's law Q = -K A dh/dl
- Hydraulic conductivity K of medium
- Transmissivity K times thickness
- Hydraulic gradient Head change per length
- Porosity Void volume fraction
- Specific yield Water that drains
- Specific retention Water held back
Conductivity vs Transmissivity HY
Conductivity K
- Property of medium
- Length per time
- Compare lithologies
Transmissivity T
- K times thickness
- Whole aquifer
- Well-yield estimates
- Medium vs aquifer
Wells + Groundwater HY
- Confined aquifer Bounded, under pressure
- Unconfined aquifer Free water table
- Storativity Water per head change
- Cone of depression Drawdown around well
- Theis solution Transient drawdown analysis
- Ghyben-Herzberg Fresh-salt interface ratio
- Retardation factor Sorption slows contaminant
Yield vs Retention HY
Specific yield
- Drains by gravity
- High in sand
- Usable storage
Specific retention
- Held by capillarity
- High in clay
- Not recoverable
- Drains vs held
Slope Failure Mode EN
- Curved surface, soil → Rotational slump
- Weak bedding plane → Planar slide
- Two joint sets → Wedge failure
- Steep inward joints → Toppling
- Saturated loose sand → Liquefaction
- Slow downslope movement → Creep
Soil + Rock Mechanics EN
- Effective stress Total minus pore pressure
- Mohr-Coulomb Cohesion plus friction strength
- Friction angle Grain shear resistance
- Atterberg limits Soil consistency states
- SPT N-value Standard blow count
- RQD Rock quality designation
- Factor of safety Resisting over driving
Hazards + Slope Failures EN
- Liquefaction Saturated sand loses strength
- Rotational slump Curved slip surface
- Planar failure Slide on plane
- Wedge failure Intersecting joint sets
- Toppling Steep joints overturn
- Rock bolt Passive tunnel support
- RMR / Q-system Rock mass rating
Resource vs Reserve EC
Resource
- Potentially economic
- Measured/indicated/inferred
- May not mine
Reserve
- Economically mineable
- Proven/probable
- Price-dependent
- Potential vs economic
Ore Deposits EC
- Porphyry copper Low-grade disseminated sulfides
- Magmatic segregation Settled dense minerals
- SEDEX Sedimentary brine sulfides
- VMS Volcanic massive sulfides
- Placer Water-concentrated heavy grains
- Skarn Contact metasomatic ore
- Hydrothermal vein Hot-fluid mineral fill
Energy + Mining EC
- Resource Potentially economic material
- Reserve Economically mineable part
- Source rock Generates hydrocarbons
- Reservoir rock Porous, permeable store
- Trap and seal Holds migrating hydrocarbons
- Acid mine drainage Sulfide oxidation acid
- Reclamation Restore mined land
Common Traps
Stress vs Strain
- Stress is force/area ≠ Strain is deformation
Conductivity vs Transmissivity
- K describes medium ≠ T describes aquifer
Yield vs Retention
- Yield drains freely ≠ Retention held tight
Weathering vs Erosion
- Weathering breaks down ≠ Erosion carries away
Resource vs Reserve
- Resource is potential ≠ Reserve is economic
Confined vs Unconfined
- Confined under pressure ≠ Unconfined water table
Till vs Stratified Drift
- Till unsorted, ice ≠ Drift sorted, meltwater
Last Minute
- 1. FG: 140 questions, 4 hours
- 2. PG: 110 questions, 4 hours
- 3. Passing score is 70 scaled
- 4. Eight content domains total
- 5. Hydrogeology dominates the PG exam
- 6. Superposition: older beds below
- 7. Bowen: mafic crystallizes first
- 8. Darcy: flow needs gradient
- 9. Effective stress = total − pore
- 10. Normal drops; reverse raises
- 11. Resource potential; reserve economic
ASBOG FG/PG
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