Rock layers can be tilted, folded and fractured by tectonic forces to produce a variety of rock structures. The tilt and orientation of rock layers and fractures are described by their strike and dip . In areas with horizontal strata and an arid climate, fluvial denudation produces vertical cliffs of resistant rock separated by gentler slopes of less resistant rock. These slopes surround flat-topped plateaus, mesas and buttes capped by resistant rock. Different rock types and structures tend to produce different drainage patterns or stream network characteristics.
Drainage patterns have some interesting, systematic geometric properties.
Areas of horizontal strata usually have a dendritic drainage pattern. On gently dipping strata along coastal plains, cuestas form in more resistant rock while lowland valleys develop in the less resistant rock. The development of consequent streams across the cuestas and subsequent streams along the lowland valleys produces a trellis drainage pattern. Fluvial denudation of a sedimentary dome produces an annular drainage pattern and a circular pattern of hogbacks of more resistant rock separated by lowlands of less resistant rock. A trellis drainage pattern is typical of these landscapes.