Abstract photography can produce very dramatic images. It relies on our more primal sense of form, color, and curves than it does on detail. The problem is that most photographers tend to think in terms of detail when evaluating photographic opportunities.
Today, matching belts of sedimentary rock, known as the Old Red Sandstone, are found in Scandinavia, the United Kingdom, and eastern North America.
Sandstones are one of the most common types of sedimentary rocks. Mudrocks. Mudrocks are made of fine grained clasts (silt and clay sized) . A siltstone is one variety that consists of silt-sized fragments. A shale is composed of clay sized particles and is a rock that tends to break into thin flat fragments (See figure 7.6e in your text).