A small structure in Wyoming, a few kilometers across. The dark red layers can be traced all the way around it. The V's formed where ravines cut the layers show that the layers are dipping outward, therefore the structure is a dome. But not a simple one. When objects of known shape deform, they are valuable indicators that allow us to quantify rock deformation.
Fossils are good indicators.
The light spot here is a reduction spot , a place where iron in the rock was chemically reduced and the reddish color of the slate bleached. The rock has been flattened in the direction of the short axis and lengthened in the direction of the long axis. Deformed rocks develop a sheetlike structure called foliation . Foliation is not bedding. This slate paving stone near Independence Hall, Philadelphia was split along a foliation surface, but weathering has revealed the original bedding in the rock.