Different types of springs
By Marjorie Henry, Contributor

I STARTED to review springs in the last lesson, paying special attention to the objectives outlined in the geography syllabus. The term was defined and information was given on the occurrence of springs. I continue this week by looking at the different types of springs.

Springs are of several kinds due to the nature of the rocks and the position of the water table.

1. In areas of tilted strata, where permeable and impermeable rocks alternate, water emerges at the base of the permeable layers.

(Fig. 1)

2. In well-jointed rocks water may percolate downwards until it reaches a joint which emerges at the surface. The water may come to the surface through the joint.

(Fig. 2)

3. Where a dyke or sill of impermeable rock is intruded through permeable rocks it causes the water table to reach the surface and the water issues as a spring.

(Fig. 3)

4. In limestone or chalk escarpments, where the permeable rock lies between impermeable strata, water issues at the foot of the scarp as a scarp-foot spring, or near the foot of the dip-slope as a dip-slope spring.

(Fig. 4)

5. In karst regions rivers often disappear underground. They then flow through passages worn in the rock by solution and may re-emerge when limestone give place to some impermeable rock. This kind of spring is sometimes called a vauclusian spring but is better referred to as a resurgence.

(Fig. 5)

The source for the above information is Certificate Physical and Human Geography by Goh Cheng Leong.

Here is a section of a question on springs taken from the June 2004 question paper:

3. Figure 3 is a diagram showing spring formation.

(a) From the list below, identify the features labelled A, B and C in Figure 3.

(i) Jointed rock
(ii) Impermeable rock
(iii) Water table (3 mks)

(b) Using the information in Figure 3, explain the formation of the springs. (3 mks)

The response to the question is as follows:

(a) (i) Jointed rock - C
(ii) Impermeable rock - A
(iii) Water table - B

(b) In the diagram above the impermeable rock is overlain by the jointed rock. The water percolates downward through the jointed rock to the impermeable rock where the water table occurs. The water flows through the joints to the surface so forming the spring.

Continue to revise the topics that come under geomorphic system. Remember that two questions are usually set on this system in the examination, and, at the same time, more than one topic is tested in each question.