1. Attitude of Beds
Attitude: A general term for the orientation of a line or plane. Attitude refers to the three dimensional orientation of planar and linear features such as a bed, a joint, a hornblende neddle or a fold.
The attitude of planar features, such as beds or joints, is defined by their strike and dip.

2. Attitude of Linear Structures
Attitude of Beds
Attitude of Linear Structures
The attitude of linear structures is defined by the trend & plunge (together they define a vector)
Trend is the bearing of the line & Plunge is the inclination of the line.
Linear structure are also defined by their pitch / rake on a given plane:
Pitch / Rake: The acute angle between the line and the strike of the plane on which the line lies.
Example of linear structures: Fold axis, hingeline, intersection of two planes, stretched pebbles, slickenside, other lineations.
Plunge
Horizontal line
Line – linear structure
Vertical Plane
Inclined Plane
Line – linear structure
Horizontal line
Pitch / Rake
Inclined Plane

3. Attitude of Planar Structures
Attitude of Beds
Attitude of Planar Structures
The attitude of planar structures is defined by the strike and dip
Strike and dip describe the orientation of a plane in space.
Strike is the bearing of a horizontal line on the plane (a scalar), i.e., N400E
Dip is the inclination of the plane measured down. Dip is a vector; it gives the direction and amount of dip of the plane.
Example for dip: 800N
80o is the amount, N is the direction.
Example of planar structure: bedding, fault, fold axial plane, layering in lava, cleavage & schistosity.

5. Attitude of Beds
Strike: Strike is the direction of a line formed by the intersection of the bedding plane with the horizontal plane. Strike is the bearing of a horizontal line on the inclined plane (a scalar). If a plane is immersed in a water, the strike line will be the water-line.
Generally expressed as an angle relative to north. i.e. N370E, N120W

6. Attitude of Beds
Dip Direction: It is the direction along which a bed dips and is perpendicular to the strike line.
The dip direction is the direction that a drop of water will flow down the plane.

7. Attitude of Beds
Dip: The dip of a bed is the angle between the bedding and horizontal plane, i.e., the amount of inclination with respect to horizontal.
It is measured in a vertical plane at right angle to the strike of the bedding. It is expressed in degrees (450), or in gradient (1 in 1), or in percentage (50%).

8. Attitude of Beds
Dip: The dip of a bed is the angle between the bedding and horizontal plane, i.e., the amount of inclination with respect to horizontal.
It is measured in a vertical plane at right angle to the strike of the bedding. It is expressed in degrees (450), or in gradient (1 in 1), or in percentage (50%). HD VD d
HD = Horizontal distance = 1 unit
VD = Vertical Distance = 1 unit
= tan d VD HD _
or, d = tan

9. Dipping Sedimentary Beds

10. Cockscomb Ridge, S. Utah
Strike
Dip

11. Attitude of Beds Two types of dip – a) True dip & b) Apparent dip
True dip : The angle between a bed and a horizontal plane measured in a vertical plane lying at right angles to the strike of the bedding. It is the maximum vertical angle of an inclined structural plane. It is denoted by d
Apparent dip: Apparent dip is the angle measured in any direction other than the true dip direction. The amount is always less than the true dip. It is denoted by r

12. Attitude of Beds tan r = tan d sin a d = true dip r = apparent dip
a = azimuth
angle between strike line
and apparent dip direction
The relation between the apparent dip and true dip is expressed by the following equation:-
tan r = tan d sin a

13. Attitude of Beds tan r = tan d sin a d = true dip r = apparent dip
a = azimuth
angle between strike line
and apparent dip direction C d F a r G d
Derived the equation:-
tan r = tan d sin a

14. Attitude of Beds Dip & Strike Symbols Block Diagram Map View
Inclined bed
Vertical bed
Horizontal bed
400

15. Attitude of Beds

16. Geologic Map and Cross Section

17. Attitude of Beds Compass-clinometer for measuring strike & dip
Silva compass
Brunton compass
Taking a bearing of a rock feature - e.g. strike
Measuring the inclination (e.g. dip)

18. Steeply Dipping Beds, Pt. Arena, Ca

19. Field Measurements

23. Maps and X-sections

24. Geologic Maps – strike & dip (angle, direction), geologic cross-sections

28. Two ways of expressing attitude
Attitude of Beds
Two ways of expressing attitude N
460 N450E
Amount of dip followed by dip direction W E AD DD S
Strike followed by amount of dip with dip component
N450W, 460 NE