Fault Wall

With my eyes on all things fault-related these days, as we're now in the third week of the San Andreas Fault National Park studio up at Columbia, I was interested in a brief moment from poet Simon Armitage's new memoir, Walking Home.

[Image: Hadrian's Wall (not the wall described below) on the Whin Sill, via Wikipedia].

While hiking with a friend across a geological formation called the Whin Sill, in the northern Pennines, Armitage learns something extraordinary:

Stopping to appreciate a high and long dry-stone wall that bisects two valleys, [his fellow hiker] Chris explains how the shape, size, colour and consistency of the stones begins to change along its course, a consequence of wall-builders using the nearest available material while quarrying across a fault-line, so the wall becomes a kind of cross-section of the bedrock below us, and a timeline also, and after a few minutes of looking I almost convince myself that I can see the difference.

Whether or not this is even geologically true—and Armitage himself seems hesitant to accept the insight—the idea that fissures in the earth can be made visible in architecture is an implication worth contemplating, as if human spatial constructions, or, more importantly, the materials from which they're made, can act as signs or perhaps symptoms for long-dead titanic events of incredible force and violence otherwise invisible inside the planet.

(Thanks to Nicola Twilley for the tip!)