Geoscience Reference
In-Depth Information
3. Plunge
Set the compass dial so that the instrument can be used as a clinometer
(see Figures 2.6, 2.7). Place the compass-clinometer along the linear
feature and read off the plunge angle from the clinometer. In this case the
plunge is 15°.
P
S
P
B
2
4. Record
Record in your notebook the plunge as a 2-digit figure (15°) and the azimuth
as a 3-digit figure (148°). For linear features the usual notation is
the plunge first, then an arrow indicating 'to' and then the azimuth (15
→
148).
Figure 2.9
Steps in the measurement of the azimuth and plunge of a linear feature (lineament) by
the contact method - for both types of compass-clinometer. The parts of the compass-clinometers are shown in
Figure 2.3.
Continued
