This was a very unpopular question among the candidates. Among those that
answered it, some had difficulty in explaining springs and caverns.
The candidates were expected to explain the following points to score high marks:
Springs
- formed when there is an easy outlet of water from the ground;
- can be formed when the water table meets the surface of the earth;
- springs develop along the junction of two rocks where limestone rocks overlay impermeable rocks;
- in springs, there are outlets of water above the water table;
- they often develop on the slopes of well jointed rocks;
- examples are commonly found in New Zealand, Italy, California Ikogosi (in Nigeria) etc.
Caverns
- an underground feature in limestone region;
- links to the surface by swallow holes;
- formed as a result of dissolution of limestone underneath the earth surface;
- with further penetration of water, some droplets are left on the roof of the cave which accumulates to form stalactites;
- some of the water droplets from the dissolved rock fall to the ground and accumulate to form stalagmites;
- stalactites and stalagmites meet to form pillars in caverns;
- examples of caverns are Batu Cave (Malasia), Mommoth cave and Kentucky cave in U.S.A., Carsbad cave (New Mexico);
- some caverns contain lakes and ponds.