---
title: "Define attitude of a rock"
subject: "Engineering Geology I"
chapter: 5
key: "semester_3/engineering_geology_i:define-attitude-of-a-rock"
source: https://www.bctengineer.com/q/semester_3/engineering_geology_i/define-attitude-of-a-rock
site: BCT Engineering
---

# Define attitude of a rock

Engineering Geology I · Chapter 5: Structural Geology

- Asked in: 2076 Chaitra, 1 marks; 2078 Kartik, 2 marks; 2076 Asoj, 1 marks; 2069 Chaitra, 2 marks; 2068 Baisakh, 1 marks; 2080 Baisakh, 1.5 marks; 2064 Jestha (old course), 4 marks (asked 7 times)
- Video: [What is Strike and Dip and How is it Indicated on a Map?](https://www.youtube.com/watch?v=-yPcPlIHDl0) — Ruppert Rocks Geology
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_3/engineering_geology_i/define-attitude-of-a-rock
- Whole chapter: https://www.bctengineer.com/md/semester_3/engineering_geology_i/chapter-5

## Question

Define attitude of a rock (geological structure) and describe the components used to express the orientation of a rock bed.

## Short answer

The attitude of a rock defines its spatial orientation using strike (horizontal line direction on the plane) and dip (maximum inclination angle and its direction perpendicular to strike). It is measured with a geological compass and expressed as N30°E/40°SE or 120°/40°.

## Answer

The **attitude** of a rock (geological structure) is its three-dimensional orientation in space, that is, the direction in which a plane or line is inclined with respect to the horizontal and to north. The attitude of a bedding plane is expressed by its **strike** and **dip**.

#### Components of attitude
1. **Strike**
   - The direction of the horizontal line drawn on an inclined plane (the line of intersection of the plane with a horizontal plane).
   - It is measured as a bearing from north, for example N45°E.
2. **Dip**
   - The maximum inclination of the plane with the horizontal, measured perpendicular to the strike.
   - It has two components: **dip direction** (the direction in which the plane goes down, at 90° to the strike) and **dip amount (angle of dip)** (the angle between the plane and the horizontal).
3. For a line (such as fold axis or lineation) the attitude is given by **trend** (compass bearing of the line projected on the horizontal) and **plunge** (angle of the line below the horizontal).

```text
             N
             |   strike
             |  /
        _____|_/______
       /    /|/      /|
      /    / /      / |
     /____/_/______/  |  dip angle (a)
     |   /-> dip direction (90 deg to strike)
     |__/___________|/
```

#### Expressing orientation
- Quadrant method: strike N30°E, dip 40° towards SE (written N30°E/40°SE).
- Azimuth (dip direction/dip) method: 120°/40°.
- Measured in the field with a **Brunton or Clar geological compass**, which gives strike with the compass and dip with a clinometer.
- Strike is always at right angles to the dip direction, so if the dip direction is known, the strike is dip direction plus or minus 90°.

## Related in Engineering Geology I

- [Fold, fault and joint; attitude](https://www.bctengineer.com/question.md?key=semester_3%2Fengineering_geology_i%3Afold-fault-and-joint-attitude) — Engineering Geology I, chapter 5
- [Strike of quartzite bed, dip 70° towards S20°E](https://www.bctengineer.com/question.md?key=semester_3%2Fengineering_geology_i%3Astrike-of-quartzite-bed-dip) — Engineering Geology I, chapter 5
- [Strike of quartzite bed dipping S25°E](https://www.bctengineer.com/question.md?key=semester_3%2Fengineering_geology_i%3Astrike-of-quartzite-bed-dipping) — Engineering Geology I, chapter 5, asked 2×
- [Strike of limestone bed dipping S55°E](https://www.bctengineer.com/question.md?key=semester_3%2Fengineering_geology_i%3Astrike-of-limestone-bed-dipping) — Engineering Geology I, chapter 5
- [Metamorphic rock, cleavage; igneous rock significance](https://www.bctengineer.com/question.md?key=semester_3%2Fengineering_geology_i%3Ametamorphic-rock-cleavage-igneous-rock) — Engineering Geology I, chapter 4
- [Three-point problem: A 600 m N, C 300 m E (500, 400, 400)](https://www.bctengineer.com/question.md?key=semester_3%2Fengineering_geology_i%3Athreepoint-problem-a-600-m) — Engineering Geology I, chapter 5

## Related in other subjects

- [Rock layer attitude: A 900 m N, C 800 m W](https://www.bctengineer.com/question.md?key=semester_4%2Fengineering_geology_ii%3Abh-rock-layer-a900n-c800w) — Engineering Geology II, chapter 6, asked 2×
- [Rock layer attitude: A 700 m N, C 600 m W](https://www.bctengineer.com/question.md?key=semester_4%2Fengineering_geology_ii%3Abh-rock-layer-a700n-c600w) — Engineering Geology II, chapter 6, asked 2×
- [Express a_x field in cylindrical, spherical](https://www.bctengineer.com/question.md?key=semester_3%2Felectromagnetism%3Aexpress-ax-cylindrical-spherical) — Electromagnetism, chapter 1
- [Borehole attitude: square 360 m, M N O P](https://www.bctengineer.com/question.md?key=semester_4%2Fengineering_geology_ii%3Abh-attitude-square-360-mnop) — Engineering Geology II, chapter 6