Page 128 - Bulletin 11 2007

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The gently-dipping to horizontally-bedded sandstone of the Peninsula Formation
provided a ready source of building blocks that were extracted by utilising the bedding

planes and joint planes. The technique of feather-wedging was applied, whereby a series
of closely-spaced boreholes were drilled, normally along a joint plane, followed by

loosening of the block using a hammer and chisel. The defunct Bishop and Williams’

Quarry in Rontree Estate, Camps Bay, is the only recorded quarry near Cape Town and
utilised loose boulders on the lower slopes of Table Mountain. (Wybergh, 1932). These

were split into building blocks and hammer-dressed, with St George’s Cathedral being
the most prominent building that utilised this sandstone. (Wybergh, 1932). The three

local building stones can be seen together in one building, namely the Western Cape
Archives in Roeland Street that was completed in 1859 as a gaol, before being

converted into archives in 1977. (Fig. 3.3; Cole, 2002).

The main constraint on the choice of building stone was transport distance, with stone

rarely being transported more than 5 km. A similar constraint was apparently applicable

th
to buildings in the South Peninsula, since the older (19 Century) buildings are
constructed of quartzitic sandstone of the Peninsula Formation and, in contrast to Cape

Town, sandstone, siltstone and mudstone of the locally present Graafwater Formation.

Malmesbury Group slate, which could only have been sourced from the Cape Town
area, was not used presumably due to the relatively long transport distance. Although

granite of the Cape Granite Suite occurs along parts of the False Bay coast, with one
exception, it has not been recognised in buildings of the South Peninsula and quarries

that were exploiting granite, such as Castle Head south of Simon’s Town, utilised the
stone for fill and road material. The one exception is the gate-supporting columns at

Saints Simon and Jude Catholic Church in Simon’s Town, which consist of light grey,

coarse-grained, porphyritic granite containing very light grey phenocrysts (lath-like
large crystals) of orthoclase feldspar. The source of this granite is not known.