Skip to main content

Strike of limestone bed, dip N40°W, 64°

Short answer

Dip direction N40°W (azimuth 320°). Strike = 320° − 90° = 50° (N50°E) and 320° + 90° = 230° (S50°W). Strike is N50°E (S50°W).

Determine the strike of the bedding plane of limestone bedrock, which has dip direction N40°W and dip amount 64°.

The strike is the direction of the horizontal line on the bed and it is always at 90° to the dip direction.

Given: Limestone bedding plane, dip direction N40°W, dip amount 64°. Dip direction = N40°W, azimuth = 320°.

Strike=dip direction±90°=320°−90°=230° or 320°+90°=50°\begin{aligned} \text{Strike} &= \text{dip direction} \pm 90° \\ &= 320° - 90° = 230° \ \text{or}\ 320° + 90° = 50° \end{aligned}

These two azimuths (50° and 230°) are the two ends of one line, so the strike is N50°E (S50°W).

                    N
     dip N40W \     |     / N50E
                \   |   /
                  \ | /
  W ----------------+--------------------- E
                  / |
                /   |
         S50W /     |
                    S
   ( / = strike line N50E-S50W,  \ = dip direction N40W, at 90 deg to strike )

Answer: Strike = N50°E (S50°W).

✓ Answer checked by Claude Opus 5.5 (high effort)

Related questions

All Engineering Geology I chapter 5 questions →