RG 2005 Flash Cards for ASBOG EXAM-
Graded A
What is the apparent dip of a bed? - ANSWER-Apparent dip of a bed or plane is the
inclination of that bed or plane in a direction not perpendicular to strike.
What is a fold line and how is it used? - ANSWER-The fold line is a hinge line along
which a vertical cross section may be constructed and then flattened out to a horizontal
or map view. It is used to represent the subsurface along any given line in a map view.
It need not be perpendicular to strike.
What is the angle and side relationships for the sin equation? - ANSWER-sin alpha
equals the opposite side divided by the hypotenuse.
What is the angle and side relationships for the tangent equation? - ANSWER-Tan
alpha equals opposite side divided by adjacent side.
- ANSWER-
What is the general form of the thickness equation and why wouldn't you want to use it?
- ANSWER-Graphically determining thickness is quicker and simpler because you have
to draw a crossection to define the variables in the equation.
If you have a flat surface and an outcrop width that is not perpendicular to strike, what
equation would you use to calculate the thickness of the unit? - ANSWER-thickness
equals the traverse distance across the outcrop times the sin of the angle between
strike and apparent dip direction times the sin of the dip.
What is the general equation for calculating the apparent dip of a bed and when can't
this equation be used? What other methods can be used as an alternative? - ANSWER-
Tangent of apparent dip equals the tangent of the dip multiplied by the sin of the angle
between strike and apparent dip direction.
This equation can't be used for solving true strike and dip from two apparent dips. in
order to solve a problem involving two apparent dips you must either solve graphically
or using the stereo net. The stereo net solution is much simpler and less time
consuming.
What defines an Index Fossil? - ANSWER-An index fossil identifies and dates the strata
in which it is found. It combines a wide geographic range with a narrow stratigraphic
occurrence.
, What is the net slip and where is it measured? - ANSWER-Net slip is the distance
between two formerly adjacent points on either side of a fault, measured on the fault
surface, in the plane of the fault.
What is an unconformity? - ANSWER-An unconformity is a gap in the geologic record;
an interruption in the depositional sequence that implies uplift and erosion have
removed part of the geological record or non deposition has occurred.
What is the Rule of Vs? - ANSWER-The outcrop of a formation as it crosses a valley
forms a V shape, as viewed on a map. The V points in the direction that the formation
underlies the valley.
What is a type locality? - ANSWER-A type locality is the place where a geologic feature,
such as a fossil species or geologic formation or member, was first recognized and
described. It contains the type section.
Define type section. - ANSWER-Type section is the originally described stratigraphic
unit to which other parts of the unit in other locations may be compared. It is preferable
to describe the location where the unit attains its maximum thickness and where the top
and bottom of the unit are exposed.
What is a strata-bound mineral deposit? - ANSWER-A strata-bound deposit is a mineral
deposit that is confined to a single stratigraphic unit.
What is a stratiform deposit? - ANSWER-A stratiform deposit is where the ore
constitutes a layer or layers in the rock. It is also strata-bound.
How do mineral resources differ from reserves? - ANSWER-Reserves are deposits that
are economically available and may be extracted profitably with existing technology.
Resources are naturally occurring deposits in such amounts or concentrations to be
mine-able now or in the future. Resources includes reserves, undiscovered reserves
and any deposits from which economic value may be derived.
How are magmatic segregation deposits formed? - ANSWER-Magmatic segregation
deposits are produced by differentiation or direct crystallization of magmas except for
deposits that have a component of hydrothermal transport. They form in magma
chambers and generally are deep-seated intrusive bodies.
What geologic conditions may form petroleum traps? - ANSWER-Traps may be formed
by:
1. deformation of reservoir rock, folding, faulting, or both,
2. stratigraphic variations in resevoir rock directly caused by the depositional
environment, primary, or unconformities, secondary,
3. hydrodynamic forces,
4. a combination of the above factors,
5. Diapirs
Graded A
What is the apparent dip of a bed? - ANSWER-Apparent dip of a bed or plane is the
inclination of that bed or plane in a direction not perpendicular to strike.
What is a fold line and how is it used? - ANSWER-The fold line is a hinge line along
which a vertical cross section may be constructed and then flattened out to a horizontal
or map view. It is used to represent the subsurface along any given line in a map view.
It need not be perpendicular to strike.
What is the angle and side relationships for the sin equation? - ANSWER-sin alpha
equals the opposite side divided by the hypotenuse.
What is the angle and side relationships for the tangent equation? - ANSWER-Tan
alpha equals opposite side divided by adjacent side.
- ANSWER-
What is the general form of the thickness equation and why wouldn't you want to use it?
- ANSWER-Graphically determining thickness is quicker and simpler because you have
to draw a crossection to define the variables in the equation.
If you have a flat surface and an outcrop width that is not perpendicular to strike, what
equation would you use to calculate the thickness of the unit? - ANSWER-thickness
equals the traverse distance across the outcrop times the sin of the angle between
strike and apparent dip direction times the sin of the dip.
What is the general equation for calculating the apparent dip of a bed and when can't
this equation be used? What other methods can be used as an alternative? - ANSWER-
Tangent of apparent dip equals the tangent of the dip multiplied by the sin of the angle
between strike and apparent dip direction.
This equation can't be used for solving true strike and dip from two apparent dips. in
order to solve a problem involving two apparent dips you must either solve graphically
or using the stereo net. The stereo net solution is much simpler and less time
consuming.
What defines an Index Fossil? - ANSWER-An index fossil identifies and dates the strata
in which it is found. It combines a wide geographic range with a narrow stratigraphic
occurrence.
, What is the net slip and where is it measured? - ANSWER-Net slip is the distance
between two formerly adjacent points on either side of a fault, measured on the fault
surface, in the plane of the fault.
What is an unconformity? - ANSWER-An unconformity is a gap in the geologic record;
an interruption in the depositional sequence that implies uplift and erosion have
removed part of the geological record or non deposition has occurred.
What is the Rule of Vs? - ANSWER-The outcrop of a formation as it crosses a valley
forms a V shape, as viewed on a map. The V points in the direction that the formation
underlies the valley.
What is a type locality? - ANSWER-A type locality is the place where a geologic feature,
such as a fossil species or geologic formation or member, was first recognized and
described. It contains the type section.
Define type section. - ANSWER-Type section is the originally described stratigraphic
unit to which other parts of the unit in other locations may be compared. It is preferable
to describe the location where the unit attains its maximum thickness and where the top
and bottom of the unit are exposed.
What is a strata-bound mineral deposit? - ANSWER-A strata-bound deposit is a mineral
deposit that is confined to a single stratigraphic unit.
What is a stratiform deposit? - ANSWER-A stratiform deposit is where the ore
constitutes a layer or layers in the rock. It is also strata-bound.
How do mineral resources differ from reserves? - ANSWER-Reserves are deposits that
are economically available and may be extracted profitably with existing technology.
Resources are naturally occurring deposits in such amounts or concentrations to be
mine-able now or in the future. Resources includes reserves, undiscovered reserves
and any deposits from which economic value may be derived.
How are magmatic segregation deposits formed? - ANSWER-Magmatic segregation
deposits are produced by differentiation or direct crystallization of magmas except for
deposits that have a component of hydrothermal transport. They form in magma
chambers and generally are deep-seated intrusive bodies.
What geologic conditions may form petroleum traps? - ANSWER-Traps may be formed
by:
1. deformation of reservoir rock, folding, faulting, or both,
2. stratigraphic variations in resevoir rock directly caused by the depositional
environment, primary, or unconformities, secondary,
3. hydrodynamic forces,
4. a combination of the above factors,
5. Diapirs
