Page 22 - KBHA BULLETIN 3

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THE SIGNIFICANCE OF THE KALK BAY CAVES

Peter Swart

Introduction

Many children from all over the Cape Peninsula have visited the Kalk Bay caves at one time
or another. “Going caving”, is something that they do, and then they grow up and move on to

other, less grubby, activities. A few wonder how the caves were formed, or who painted the

names at the cave entrances, but few realize just how privileged they are to have such exciting
places right on their door step, and fewer still realize how much history is hidden behind

those painted names. This article attempts to show that the caves above Kalk Bay are

significant, by explaining how they were formed, and giving a brief outline of the recent
history of human interaction with them.

Geology

One of the most significant things about the Kalk Bay caves is that they exist. The older

textbooks tell us that most caves form in a rock that is easily dissolved in water. Limestone,
dolomite and other carbonate-based rocks dissolve relatively easily in water, while the

quartzitic sandstone that makes up the Kalk Bay mountains does not dissolve as easily, and it

is for this reason that the mere existence of the caves above Kalk Bay is of interest.

Unfortunately, for those who maintain that quartzite does not dissolve, there are caves above

Kalk Bay, so we have to find an explanation for their creation. First of all, let’s look at how
caves form in a soluble rock, and then see if we can find any similarities between traditional

cave formation and the geology of the Silvermine Nature Reserve.

The type of landscape that evolves where water erodes limestone is called Karst, and areas of

Karst are the areas where caves are found. Karst forms when water filters into massive beds
of rock through tiny cracks and capillaries. The water, usually acting under the force of

gravity, passes through the rock, and out of the other side. The distance that the water travels