oil on canvas,
22cm x 20cm,
Iain White, 2015,
The Moine Thrust Belt forms the outer, NW margin to the Scottish Caledonides. As such it provides spectacular examples of the range of structures found within the marginal zone of an orogenic belt.
Among these are dip-slip faults on which the hanging wall block has moved up relative to the footwall block. They accommodate horizontal shortening of the Earth’s crust. Known as imbricate thrusts, these thrust/reverse faults are those which form an array of steeply angled faults, diverging from an underlying fault (the floor thrust). Where these imbricate thrust faults recombine up-dip onto another major fault (the roof thrust), ie bounded from below and above, the entire structure is termed a duplex.
Such duplex structures occur at a range of scales. Here we see a relatively small scale local example within the pipe rock of the Cambrian.