Determination of the top and bottom
surfaces from graded bedding
Determination of the top and bottom surfaces
from cross-bedding
Determination of the top surfaces of the
beds from the scour surfaces
Parallel unconformity,Angular Unconformity
Feather edge
K— Cretaceous
J — Jurassic
T— Triassic
P— Permian
? — Granite
CHAPTER 3
ATTITUDE OF PLANES AND LINES
Planar and Linear Features
Planes
1) Bedding
2) Cleavage
3) Joints
4) Faults
Lines
1) Elongate minerals
2) Intersection of 2
planes
3) Striae on fault surface
Horizontal Beds
Incli ned Bed s
CLEAVAGE IN DONGGOUBA GOLD
DEPOSIT,SHAANXI PROVINCE
STRIKE-SLIP FAULT,NEVADA
Photo,Martin Miller,U of Oregon
WASATCH FAULT,UTAH
? Strike and dip of the fault
?Trend and plunge of fault striae
Strike,the unique direction of a horizontal straight
line on an inclined plane.
Dip direction,the direction in which the plane dips
downwards from the surface,It is always 90° from
the strike direction.
Dip:the inclination of a planar surface.
Plunge,the angle between the line and the horizontal in the vertical
plane.
Plunge direction,the trend of the line in which the plunge is
measured
True dip,the inclination of the line of greatest slop on an inclined
plane,It is measured perpendicular to the Strike.
Apparent dip,the inclination of a line on an inclined plane
measured in a direction oblique to the strike Direction.It is always
less than true Dip.
Equation:
b = atan[tan(a)cos(d)]
b= apparent dip angle,a = true dip angle,d = angle between
true and apparent dip direction.
a
b
d
APPARENT DIP ANGLE CALCULATION
Zhu Zhicheng et al,[China University of Geosciences]
Strike and dip of a plane
Trend & plunge of a line Pitch and pitch direction
Relationship between true dip(a) and
Apparent dip(b or b?)
Compass,‘Brunton’
NE
SE
NW
SW
0
90270
180Trend,S30W Trend,210
Bearing Azimuth
Bearing and Azimuth
?Bearing,a horizontal angle measured east or west of true
north or south.
?Azimuth,a horizontal angle measured clockwise from the
true north.
?Trend,the direction of a line in a horizontal plane,
commonly specified by its bearing or azimuth.
Rake or
Pitch Angle
Definition of Rake or Pitch Angle
Plane,035 / SE ∠ 79
or 125 ∠ 79
Rake,62 E
The line is on the plane
PLUNGE AND DIP ANGLE
? line -> plunge (measured downward from the horizontal)
? plane -> dip (measured downward from horizontal,and
perpendicular to strike.)
Map Symbols,
23 47
N
Map symbols for structural planes
Map Symbols for Lines
30
Exercises In Class
? Measure the strikes,dip direction,dip of planes,
record the data on a paper and draw them on a map.
? Measure the plunge directions,plunges,pitch of
lines,record the data on a paper and draw them on a
map,
Note
Bring a compass and a pencil next time
Preview Rule of ‘Vs’
Rules of ‘Vs’(the handout and
Reference Book Page 233)
surfaces from graded bedding
Determination of the top and bottom surfaces
from cross-bedding
Determination of the top surfaces of the
beds from the scour surfaces
Parallel unconformity,Angular Unconformity
Feather edge
K— Cretaceous
J — Jurassic
T— Triassic
P— Permian
? — Granite
CHAPTER 3
ATTITUDE OF PLANES AND LINES
Planar and Linear Features
Planes
1) Bedding
2) Cleavage
3) Joints
4) Faults
Lines
1) Elongate minerals
2) Intersection of 2
planes
3) Striae on fault surface
Horizontal Beds
Incli ned Bed s
CLEAVAGE IN DONGGOUBA GOLD
DEPOSIT,SHAANXI PROVINCE
STRIKE-SLIP FAULT,NEVADA
Photo,Martin Miller,U of Oregon
WASATCH FAULT,UTAH
? Strike and dip of the fault
?Trend and plunge of fault striae
Strike,the unique direction of a horizontal straight
line on an inclined plane.
Dip direction,the direction in which the plane dips
downwards from the surface,It is always 90° from
the strike direction.
Dip:the inclination of a planar surface.
Plunge,the angle between the line and the horizontal in the vertical
plane.
Plunge direction,the trend of the line in which the plunge is
measured
True dip,the inclination of the line of greatest slop on an inclined
plane,It is measured perpendicular to the Strike.
Apparent dip,the inclination of a line on an inclined plane
measured in a direction oblique to the strike Direction.It is always
less than true Dip.
Equation:
b = atan[tan(a)cos(d)]
b= apparent dip angle,a = true dip angle,d = angle between
true and apparent dip direction.
a
b
d
APPARENT DIP ANGLE CALCULATION
Zhu Zhicheng et al,[China University of Geosciences]
Strike and dip of a plane
Trend & plunge of a line Pitch and pitch direction
Relationship between true dip(a) and
Apparent dip(b or b?)
Compass,‘Brunton’
NE
SE
NW
SW
0
90270
180Trend,S30W Trend,210
Bearing Azimuth
Bearing and Azimuth
?Bearing,a horizontal angle measured east or west of true
north or south.
?Azimuth,a horizontal angle measured clockwise from the
true north.
?Trend,the direction of a line in a horizontal plane,
commonly specified by its bearing or azimuth.
Rake or
Pitch Angle
Definition of Rake or Pitch Angle
Plane,035 / SE ∠ 79
or 125 ∠ 79
Rake,62 E
The line is on the plane
PLUNGE AND DIP ANGLE
? line -> plunge (measured downward from the horizontal)
? plane -> dip (measured downward from horizontal,and
perpendicular to strike.)
Map Symbols,
23 47
N
Map symbols for structural planes
Map Symbols for Lines
30
Exercises In Class
? Measure the strikes,dip direction,dip of planes,
record the data on a paper and draw them on a map.
? Measure the plunge directions,plunges,pitch of
lines,record the data on a paper and draw them on a
map,
Note
Bring a compass and a pencil next time
Preview Rule of ‘Vs’
Rules of ‘Vs’(the handout and
Reference Book Page 233)
