---
title: "Recognising sedimentary, metamorphic, igneous rocks"
subject: "Engineering Geology I"
chapter: 4
key: "semester_3/engineering_geology_i:recognising-sedimentary-metamorphic-igneous-rocks"
source: https://www.bctengineer.com/q/semester_3/engineering_geology_i/recognising-sedimentary-metamorphic-igneous-rocks
site: BCT Engineering
---

# Recognising sedimentary, metamorphic, igneous rocks

Engineering Geology I · Chapter 4: Petrology

- Asked in: 2061 Baisakh (old course), 4 marks
- Video: [Types of Rocks Igneous-Sedimentary-Metamorphic Rocks](https://www.youtube.com/watch?v=TbHB7xUjMIk) — MooMooMath and Science
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_3/engineering_geology_i/recognising-sedimentary-metamorphic-igneous-rocks
- Whole chapter: https://www.bctengineer.com/md/semester_3/engineering_geology_i/chapter-4

## Question

Describe the features for recognising sedimentary, metamorphic and igneous rocks.

## Answer

| Feature | Sedimentary | Metamorphic | Igneous |
|---|---|---|---|
| Layering | Bedded, in distinct layers | Foliated or banded | Massive, no layers |
| Texture | Clastic grains cemented, or crystalline (chemical) | Crystalline; flaky, banded or sugary | Interlocking crystals or glassy |
| Fossils | Often present | Absent or distorted | Absent |
| Surface marks | Ripple marks, mud cracks | Folds, crumpled bands | Vesicles in lava, columnar joints |
| Minerals | Quartz, calcite, clay, gypsum | Mica, garnet, kyanite, chlorite, talc | Quartz, feldspar, mica, pyroxene, olivine |
| Hardness | Soft to moderate | Moderate to hard | Hard |
| Examples | Sandstone, shale, limestone | Slate, schist, gneiss, marble | Granite, basalt, gabbro |
| Occurrence | Basins, river and sea beds | Mountain belts, contact zones | Volcanic regions, intrusions |

## Check yourself

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

1. Which rock class is typically massive with no layers?
   A. Igneous
   B. Sedimentary
   C. Metamorphic foliated
   D. Chemical sedimentary
   Answer: A. Sedimentary are bedded, metamorphic foliated, igneous massive. (Key point: Layering)

2. Fossils are
   A. common in igneous and absent in sedimentary
   B. often present in sedimentary, absent or distorted in metamorphic, and absent in igneous rocks
   C. common in metamorphic
   D. absent from all three classes
   Answer: B. Fossils survive in sedimentary rock. (Key point: Fossils)

3. Which mark goes with igneous rocks?
   A. Ripple marks
   B. Crumpled bands
   C. Vesicles in lava and columnar joints
   D. Mud cracks
   Answer: C. Ripple marks and mud cracks are sedimentary; folds metamorphic. (Key point: Surface marks)

4. Which mineral group is typical of metamorphic rocks?
   A. Olivine, pyroxene, quartz
   B. Gypsum, calcite, clay
   C. Coal and lignite
   D. Mica, garnet, kyanite, chlorite, talc
   Answer: D. That group is listed for metamorphic rocks. (Key point: Minerals)

## Related in Engineering Geology I

- [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
- [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
- [Metamorphic rock formation; igneous rock texture](https://www.bctengineer.com/question.md?key=semester_3%2Fengineering_geology_i%3Ametamorphic-rock-formation-igneous-rock) — Engineering Geology I, chapter 4
- [Texture of igneous rocks](https://www.bctengineer.com/question.md?key=semester_3%2Fengineering_geology_i%3Atexture-of-igneous-rocks) — Engineering Geology I, chapter 4, asked 4×
- [Intrusive versus extrusive igneous rocks](https://www.bctengineer.com/question.md?key=semester_3%2Fengineering_geology_i%3Aintrusive-versus-extrusive-igneous-rocks) — Engineering Geology I, chapter 4, asked 3×
- [Classification of igneous rocks](https://www.bctengineer.com/question.md?key=semester_3%2Fengineering_geology_i%3Aclassification-of-igneous-rocks) — Engineering Geology I, chapter 4

## Related in other subjects

- [Sedimentary versus igneous stones](https://www.bctengineer.com/question.md?key=semester_3%2Fcivil_engineering_materials%3Asedimentary-igneous-stones) — Civil Engineering Materials, chapter 2