The correct option is 1 only
Explanation
In Karst topography, groundwater acts as a prominent geomorphic agent. Depositional landforms within limestone caves are created through the precipitation of calcium carbonate (calcite) as water rich in dissolved minerals drips from the ceiling or flows over the floor.
Statement-wise Analysis:
- Statement 1 is Correct: Stalactites are depositional features that hang from the cave roof, resembling icicles. They form as water drips from cracks in the ceiling and evaporates or releases carbon dioxide, causing calcite to precipitate. Morphologically, they are typically broad at their bases (attachment points) and taper towards their free ends.
- Statement 2 is Incorrect: Stalagmites do not hang from the roof; they rise upwards from the floor of the caves. They are generated by water dripping from the roof or from stalactites onto the ground.
- Statement 3 is Incorrect: Stalagmites can take various forms, including that of a column or a disc, often featuring a rounded or bulging end. Furthermore, if a stalagmite grows tall enough to meet a hanging stalactite, they fuse to form a continuous structure called a pillar or column. Thus, it is incorrect to state that they never take the shape of a column.
Key Takeaway:
Stalactites hang from the ceiling (Tapering), while Stalagmites grow from the ground (Columnar/Mound-like). The fusion of the two forms a Pillar.