Having spent a lot of time in quarries, I have had cause to reflect on the character of stone, and how the processes involved in extracting stone influence its appearance. In many cases, what we assume to be the ‘natural’ form of stone is an artefact of the process, commonly as a result of explosives (although sometimes by mechanical means). Rather than the extreme force of the earth heaving, we are often simply looking at the face of sudden, artificial blasting.
It is therefore interesting (and instructive) to look at stone within natural cliff faces and outcrops to register the variety of forms in which they can occur. This was of significance to us for a project on which we are designing paving with a comparatively orthogonal character; an arrangement that seems counter-intuitive in comparison to the majority of schist paving laid down in Central Otago.
As part of research into the surrounding landscape at Lake Hawea, we looked into natural rock faces, in which straight lines and near-rectangular forms abound. One of these places was a beautiful outcrop, on which we were also able to observe a particularly good grey scrub community containing Myrsine divaricata (pictured above, right), Coprosma dumosa (shown below, left), Coprosma crassifolia, Brachyglottis haastii and many other species with potential for cultivation in native plantings.
The outcrop also provided vindication for our sense that a more regular geometry is closer to the way in which many of these stones are shaped within nature. In the case of schist, this was unsurprising to me, on the basis of cliffs that we had already seen here and elsewhere, and also due to the nature of sedimentary stones such as this (which can have surprisingly straight-sided geometries).