Brunton GeoTransit, Operator'S Manual

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2. Stand on top, or behind the lineation and face the
direction of the plunge.
3. Hold compass at waist level and look down through the long
sight, aligning the pencil with the long sight. (Fig 29)
4. When bubble is centered in the round level, read the
trend at “ S ” end of the needle.
6.2 Plunge Measurement
Plunge is the inclination between the lineation and a
horizontal line.
1. Move to the side of the lineation, or right angles to its
trend.
2. Open both the cover and large
sight until they extend in a straight line.
3. Measure plunge using a Brunton non-
magnetic tripod, or by holding the transit
in your hand. (Fig. 30)
A United States Geological Survey (USGS) topographic map is a 2-dimensional drawing of 3-
dimensional terrain. Hills, valleys, ridges, cliffs and other terrain are represented through a
series of contour lines. Each line represents constant elevation in feet or meters above sea
level. Find the contour interval in the legend of the topographic map. With practice, you’ll
begin to recognize contours, labeling and identify passable routes.
Figure 29
2. Place GEO on its side and along on the rock surface, so
the vernier scale is at the bottom. (Fig 27)
3. Adjust vernier until bubble is centered in long level.
4. Read dip angle at the vernier’s center line, bottom scale.
5.3 Dip Measurement using Hinge Inclinometer
This method uses the lid hinge inclinometer.
1. Place transit hinge next to the outcropping. (Fig 28)
2. Adjust cover to the angle of the outcropping.
3. Hold level by centering bubble in the round level.
4. Read dip angle at the
hinge inclinometer scale.
Hint: If the GEO transit is not in a position to view the round
level, use the side/bottom long levels.
5.4 Dip Direction
After measuring dip using the hinge inclinometer, now
measure the dip direction.
1. With hinge next to outcropping and GEO transit level,
measure the dip direction. (Fig 28)
2. Read dip direction at the “ S ” tip.
Trend and plunge are usually non-contact linear measurements, unlike strike and dip which
are planar measurements. However, both methods provide similar information.
6.1 Trend Measurement
Trend is the direction that the lineation points downward (plunges).
1. Place a pen, pencil, or anything straight in the direction the lineation points down (plunges).
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Figure 28
Figure 27
Figure 30
6 -- Trend & Plunge Measurement
7 -- GEO Transit & Topographic Map Use