Which one of the following is depositional landform?

In karst topography, landforms are categorized into erosional and depositional features. Stalagmites are depositional landforms that rise from the cave floor [1]. They form when mineral-rich water drips from the cave ceiling or a stalactite, and the subsequent evaporation or degassing of carbon dioxide causes calcium carbonate to precipitate and accumulate as a mound-shaped deposit [6]. Conversely, sinkholes and caves are primarily erosional features formed by the dissolution of soluble rocks like limestone by groundwater [5]. Sinkholes are depressions formed by surface dissolution or the collapse of underground voids [3]. Lapis (specifically lapis lazuli) is a metamorphic rock/gemstone rather than a karst landform. Therefore, among the given options, only the stalagmite represents a feature created through the process of mineral deposition [3].

Sources

1. [1] FUNDAMENTALS OF PHYSICAL GEOGRAPHY, Geography Class XI (NCERT 2025 ed.) > Chapter 6: Landforms and their Evolution > Stalactites, Stalagmites and Pillars > p. 53
2. [3] https://www.nps.gov/maca/learn/nature/stalactites-stalagmites-and-cave-formations.htm
3. [6] https://www.sciencedirect.com/science/article/pii/S2589471424000202
4. [4] https://en.wikipedia.org/wiki/Sinkhole
5. [5] https://www.usgs.gov/water-science-school/science/sinkholes
6. [2] Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.) > Chapter 13: Types of Rocks & Rock Cycle > Chemically Formed Sedimentary Rocks > p. 171