---
title: "Short note: Stalagmite and stalactite"
subject: "Engineering Geology I"
chapter: 6
key: "semester_3/engineering_geology_i:short-note-stalagmite-and-stalactite"
source: https://www.bctengineer.com/q/semester_3/engineering_geology_i/short-note-stalagmite-and-stalactite
site: BCT Engineering
---

# Short note: Stalagmite and stalactite

Engineering Geology I · Chapter 6: Physical Geology

- Asked in: 2075 Chaitra, 2 marks
- Video: [How Stalactites & Stalagmites are formed in Karst Topography?](https://www.youtube.com/watch?v=7IeaPBqFh2E) — Geography A-Z
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_3/engineering_geology_i/short-note-stalagmite-and-stalactite
- Whole chapter: https://www.bctengineer.com/md/semester_3/engineering_geology_i/chapter-6

## Question

Write a short note on stalagmite and stalactite.

## Short answer

Stalactites are icicle-shaped calcite deposits hanging from cave roofs, while stalagmites are cone-shaped deposits rising from the floor. Both form from dripping water that loses CO2 and precipitates calcium carbonate; when they join, a column forms.

## Answer

Both are **cave deposits (speleothems)** of calcite formed when water dripping through limestone cave roofs loses CO$_2$ and deposits calcium carbonate.

- **Stalactite:** an icicle-shaped cone **hanging down** from the cave roof; it grows downward from drip-water.
- **Stalagmite:** a cone **rising up** from the floor, built where drops fall.
- When both join, they form a **column (pillar)**.

```text
   ______________ roof
     \/  \/ \/   stalactites
      .    .
      .    .
     /\   /\     stalagmites
   ____________ floor
```

## Check yourself

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

1. Stalactites and stalagmites form when:
   A. Dripping water loses CO2 and deposits calcium carbonate
   B. Lava cools
   C. Ice melts
   D. Wind drops sand
   Answer: A. They are calcite speleothems. (Key point: Formation)

2. A stalactite:
   A. Rises from the floor
   B. Hangs down from the cave roof
   C. Is a column
   D. Is on the surface
   Answer: B. Stalagmite rises up. (Key point: Stalactite)

3. A stalagmite grows:
   A. Downward from roof
   B. Sideways
   C. Upward from the floor where drops fall
   D. In the sea
   Answer: C. Built under drips. (Key point: Stalagmite)

4. When they join they form:
   A. A tarn
   B. A polje
   C. An arch
   D. A column (pillar)
   Answer: D. Roof and floor deposits meet. (Key point: Column)