This document discusses plane structure and how to represent the orientation of planes using strike and dip or dip and dip direction. It defines strike as the horizontal line where a planar structure intersects an imaginary horizontal plane, while dip is the angle between the planar structure and a horizontal plane measured perpendicular to strike. There are two common ways to write the orientation: strike and dip, which provides the strike direction and dip angle; or dip and dip direction, which provides the dip angle and azimuth of dip direction. Various classifications of dip angles are also presented, along with examples of how different planar features are described using strike and dip notation.

1. Plane Structure
Lecture #15

2. Introduction
The attitude of plane structure can be
represented by number
There are two way to write the number:
1. Strike and dip
2. Dip and dip direction

3. Strike Plane Structure
 Is a horizontal line on the plane
 Is a cross section of imaginary horizontal
plane to the plane structure
 The cross section of two plane known as
line.

4.  Strike of plane structure is an angle between the
strike with the true north.
 Strike is an angle of horizontal line on the plane
with the true north
 Two way to descript strike:
1. Quadrant convention: N45E; S45W
2. Azimuth convention (Clock wise): N135E; N225E
Quadrant Azimuth

5. Dip (True Dip)
 An angle between plane structure with horizontal
plane which measured from certain vertical plane
 The certain vertical plane perpendicular with
strike
 On the plane structure, true dip always the
biggest dip slope and the direction perpendicular
to the strike, which is down slope.
 Apparent dip is dip that measured on the
vertical plane which is not perpendicular to strike
 The magnitude of the apparent dip smaller
compare to the true dip.

7. Dip Classification for Bedding
Shallow 0° – 20°
Moderate 20° – 50°
Steep 50° – 90°
An overturned bedding, the dip always descript as
an angle that less than 90 degree (but the symbol
of the dip on map will be different).

8. Common writing type for strike
and dip direction on plane
structure
Strike and dip Dip and dip
Quadrant Azimuth direction
N0°E/80°E N360°E/80°E 80°/N90°E

9. Right Hand Rule
 Azimuth/bearing of strike is
the front vision
 Dip is the right hand (90
degree from strike – clock
wise rotation)

10. Strike and dip of
bedding
Overturned bedding
Top vertical bedding
Horizontal Bedding
Foliation strike and dip
Vertical Foliation
Strike Horizontal and Foliation
dip Symbol on Map
Cleavage strike and dip
Vertical Cleavage
Horizontal Cleavage
Vein strike and dip
Vertical Vein
Horizontal Vein
Attitude N80°E/45° or
S80°W/45°E or 45°,
N170°E