Trough cross-bedding in the Waddens Cove Formation (Pennsylvanian), Sydney Basin, Nova Scotia.
In geology, a trough refers to a linear depression that extends in one direction over a distance. It is less steep than a trench. A trough can be a narrow basin or a geologic rift. There are various oceanic troughs, troughs found under oceans; examples include the rifts along the mid-ocean ridges.