---
title: "Identify fold in the field"
subject: "Engineering Geology I"
chapter: 5
key: "semester_3/engineering_geology_i:identify-fold-in-the-field"
source: https://www.bctengineer.com/q/semester_3/engineering_geology_i/identify-fold-in-the-field
site: BCT Engineering
---

# Identify fold in the field

Engineering Geology I · Chapter 5: Structural Geology

- Asked in: 2072 Chaitra, 2 marks; 2076 Asoj, 1.5 marks (asked 2 times)
- Video: [Structural geology  - Folds Recognition of fold, class explained in English](https://www.youtube.com/watch?v=lYAxezHO8Go) — Success Guru
- 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-fold-in-the-field
- Whole chapter: https://www.bctengineer.com/md/semester_3/engineering_geology_i/chapter-5

## Question

How can you identify a fold in the field? What are the field evidences of fold?

## Short answer

Folds show repetition of beds in reverse order, opposite dips on both sides of an axis, older beds in anticline cores and younger in synclines, drag folds, and curved outcrop patterns.

## Answer

A fold is identified in the field by the following evidences.

- **Repetition of beds** in reverse order on both sides of an axis (A B C D C B A).
- **Opposite dips** on two sides of a line (axis), either converging (syncline) or diverging (anticline).
- **Outcrop pattern** on a map: a series of curved or zig-zag outcrops (V-shaped patterns) with plunge.
- **Age relation**: in an anticline older beds are in the core; in a syncline younger beds are in the core.
- **Drag folds and minor folds** in the small scale, and variation of strike or dip along a traverse.
- **Topography**: ridges and valleys following the folded beds, and plunging noses on hill slopes.
- **Cleavage or joints** (fan or radiating pattern) related to the axial plane.

## Check yourself

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

1. Reverse repetition indicates?
   A. Fault
   B. Unconformity
   C. Joint
   D. A fold
   Answer: D. ABCDCBA. (Key point: Repetition)

2. Syncline core?
   A. Younger beds
   B. Older
   C. Igneous
   D. None
   Answer: A. Anticline older. (Key point: Syncline)

3. Converging dips?
   A. Anticline
   B. Syncline
   C. Fault
   D. Monocline
   Answer: B. Diverging is anticline. (Key point: Dips)

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