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

# Identify metamorphic rock in the field

Engineering Geology I · Chapter 4: Petrology

- Asked in: 2081 Baisakh (new course), 2 marks; 2080 Bhadra, 1 marks (asked 2 times)
- Video: [Identifying Metamorphic Rocks -- Earth Rocks!](https://www.youtube.com/watch?v=HUydPhIaQQU) — Earth Rocks!
- 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-metamorphic-rock-in-the
- Whole chapter: https://www.bctengineer.com/md/semester_3/engineering_geology_i/chapter-4

## Question

How do you identify a metamorphic rock in the field?

## Short answer

Metamorphic rocks show foliation (slaty cleavage, schistosity, banding), sugary interlocking texture in non-foliated types, and metamorphic minerals (garnet, kyanite). They lack fossils, display deformation structures, and are hard and dense, often found near mountain belts.

## Answer

A metamorphic rock can be recognised in the field by these features.

1. **Foliation**: parallel arrangement of minerals, banding or flaky layers (slate, phyllite, schist, gneiss).
2. **Slaty cleavage** or schistosity: splits into thin sheets, with silky or shiny mica surface.
3. **Crystalline, interlocking, "sugary" texture** in non-foliated types (marble, quartzite).
4. **Metamorphic minerals** present: garnet, kyanite, staurolite, chlorite, talc, epidote.
5. **Deformed or distorted** structures such as folds, stretched pebbles, and lenticular bands.
6. **No fossils** (or highly distorted ones).
7. Hard and dense; the rock is often found near mountain belts, fault zones or intrusions.

## Check yourself

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

1. Which feature most characteristically identifies many metamorphic rocks in the field?
   A. Ripple marks and mud cracks
   B. Abundant fossils
   C. Foliation, the parallel arrangement of minerals or banding
   D. Vesicles
   Answer: C. Foliation (slate, phyllite, schist, gneiss) is a main field clue. (Key point: Foliation)

2. How do non-foliated metamorphic rocks like marble look?
   A. Clear layers of different grain size
   B. Gas holes filled with calcite
   C. Rounded pebbles in a matrix
   D. Crystalline, interlocking, sugary texture
   Answer: D. Marble and quartzite show sugary crystalline texture without layers. (Key point: Non-foliated types)

3. Which minerals point to a metamorphic rock?
   A. Garnet, kyanite, staurolite, chlorite
   B. Olivine and pyroxene only
   C. Gypsum and rock salt
   D. Coal and lignite
   Answer: A. These are typical metamorphic minerals. (Key point: Index minerals)

## Related in Engineering Geology I

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