---
title: "Identify sedimentary rocks in the field"
subject: "Engineering Geology I"
chapter: 4
key: "semester_3/engineering_geology_i:identify-sedimentary-rocks-in-the"
source: https://www.bctengineer.com/q/semester_3/engineering_geology_i/identify-sedimentary-rocks-in-the
site: BCT Engineering
---

# Identify sedimentary rocks in the field

Engineering Geology I · Chapter 4: Petrology

- Asked in: 2076 Chaitra, 1 marks
- Video: [SEDIMENTARY ROCKS  //  Detailed Guide](https://www.youtube.com/watch?v=5oMjoS5Wo5Y) — Let's Go Geo
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_3/engineering_geology_i/identify-sedimentary-rocks-in-the
- Whole chapter: https://www.bctengineer.com/md/semester_3/engineering_geology_i/chapter-4

## Question

How do you identify sedimentary rocks in the field?

## Short answer

Sedimentary rocks are recognized by bedding, clastic texture with cemented grains, fossils, surface marks (ripple marks, mud cracks), relative softness, and occurrence in layered sequences.

## Answer

Sedimentary rocks can be recognised in the field by:
1. **Bedding (stratification)**, in parallel layers of different colour or grain size.
2. **Clastic texture**: rounded or angular grains cemented together; gritty feel in sandstone; fine and smooth in shale.
3. **Fossils** (shells, plants, bones).
4. **Surface marks**: ripple marks, mud cracks, cross-bedding, raindrop prints.
5. **Softness**: often scratched more easily than igneous rocks; limestone effervesces with dilute HCl.
6. **Occurrence**: as layered sequences in basins and river valleys, often with pebble beds and conglomerates.

## Check yourself

The answer's key points as multiple-choice questions, with the correct option and why.

1. Which feature is most typical of sedimentary rocks?
   A. Interlocking crystals in a massive body
   B. Bedding in parallel layers
   C. Foliation from pressure
   D. Baked contacts
   Answer: B. Stratification is a main clue. (Key point: Bedding)

2. Which surface marks indicate sedimentary rock?
   A. Columnar joints
   B. Stretched pebbles
   C. Ripple marks and mud cracks
   D. Garnet crystals
   Answer: C. Ripple marks, mud cracks, cross-bedding and raindrop prints are sedimentary. (Key point: Surface marks)

3. How can limestone be identified?
   A. It shows silky mica sheen
   B. It has pink feldspar crystals
   C. It is vesicular
   D. It effervesces with dilute HCl
   Answer: D. Calcite reacts with acid. (Key point: Limestone test)

## Related in Engineering Geology I

- [Classification of sedimentary rocks](https://www.bctengineer.com/question.md?key=semester_3%2Fengineering_geology_i%3Aclassification-of-sedimentary-rocks) — Engineering Geology I, chapter 4, asked 4×
- [Texture of sedimentary rocks](https://www.bctengineer.com/question.md?key=semester_3%2Fengineering_geology_i%3Atexture-of-sedimentary-rocks) — Engineering Geology I, chapter 4, asked 2×
- [Recognising sedimentary, metamorphic, igneous rocks](https://www.bctengineer.com/question.md?key=semester_3%2Fengineering_geology_i%3Arecognising-sedimentary-metamorphic-igneous-rocks) — Engineering Geology I, chapter 4
- [Formation of sedimentary and metamorphic rocks](https://www.bctengineer.com/question.md?key=semester_3%2Fengineering_geology_i%3Aformation-of-sedimentary-and-metamorphic) — Engineering Geology I, chapter 4
- [Texture of sedimentary rocks and rock cleavage](https://www.bctengineer.com/question.md?key=semester_3%2Fengineering_geology_i%3Atexture-of-sedimentary-rocks-and) — Engineering Geology I, chapter 4
- [Petrography; structure of sedimentary rocks](https://www.bctengineer.com/question.md?key=semester_3%2Fengineering_geology_i%3Apetrography-structure-of-sedimentary-rocks) — Engineering Geology I, chapter 4

## Related in other subjects

- [Field identification of fine-grained soils](https://www.bctengineer.com/question.md?key=semester_4%2Fsoil_mechanics%3Afield-identification-clay-silt) — Soil Mechanics, chapter 3, asked 4×
- [Field tests for sand and clay](https://www.bctengineer.com/question.md?key=semester_4%2Fsoil_mechanics%3Afield-tests-sand-clay) — Soil Mechanics, chapter 3