Question

Which of the following must be true in a dry limestone cave? Select all that apply. A. Water once entered the cave. B. The cave was formed by volcanic means. C. Any cave formations are no longer growing. D. There must only be stalagmites, no stalactites.

Answer 1

Option b is correct..

Caves are formed by the dissolution of limestone. Rainwater picks up carbon dioxide from the air and as it percolates through the soil, which turns into a weak acid. This slowly dissolves out the limestone along the joints, bedding planes and fractures, some of which become enlarged enough to form caves.