1. Introduction to the Brunton Compass
Parts of the Compass
Uses of the Brunton Compass
- Bearing
- Strike and Dip
- Trend and Plunge
Map Symbols
Text: Compton, p ; 34-39; Measurement of Attitude and Location; Lab 1 (website)

2. Parts of the Compass Compass Face - Arrow (white tip North)
- Directional Degrees (Quadrant or Azimuth)
Clinometer: Scales in Degrees and % Grade
Levels
- Bullseye Level
- Cylindrical Level
Mirror
Sighting Arm
Dampener
Magnetic Declination (~6.5° E of N)

3. Uses of the Brunton Compass
Locate North
Sight Angles
- measuring height / thickness of a feature
Bearing
Strike and Dip
Trend and Plunge

4. Bearing Bearing: direction from one point to another point.
1-directional line
Quadrant Notation: N or S____° E or W
Azimuth Notation: _____°
Note: With sighting arm pointing to object, always read the white tip of the needle.

5. Strike and Dip
Strike: Direction of the line of intersection between a tilted plane and a horizontal plane.
2-directional line
Azimuth Notation: _____ °
Note: Read the end of compass needle that makes dip direction to the right of the strike direction (Right-Hand-Rule).

6. Note: If use Right-Hand-Rule, dip direction is implied.
Strike and Dip
Dip: Angle between a tilted plane and a horizontal plane that is perpendicular to strike.
Maximum angle ( ≤ 90º )
Notation: ____ ° N, S, E, W, NE, NW, SE, SW
Note: If use Right-Hand-Rule, dip direction is implied.

7. Cross-Section: Dipping StrataW E
Horizontal
Dip Angle
(E. McBride)
Cross-Section: Dipping Strata

8. Cross-Section: Dipping StrataW E
Horizontal
Dip Angle
(E. McBride)
Cross-Section: Dipping Strata

9. Aerial View: Strike of Dipping Strata
(E. McBride)

10. Trend and Plunge Trend: bearing of a linear feature.
1-directional Line
Measured in Direction of Plunge
Azimuth Notation: _____°
Plunge: angle between a tilted linear feature and a horizontal plane.
Notation: ____°
Note: written as plunge, bearing

11. Trend and Plunge
Linear Glacial Striations (Maine)

12. Map Symbols (map view) strike and dip strike and dip (vertical)
strike and dip (horizontal)
45º

13. Bring to Lab Course Packet Brunton Compass Field Notebook
Ruler (metric)
Protractor
Calculator (tangent)
Clipboard