Depression (geology)

• Blowout: a depression created by wind erosion typically in either a partially vegetated sand dune ecosystem or dry soils.
• Glacial valley: a depression carved by erosion by a glacier.
• River valley: a depression carved by fluvial erosion by a river.
• Area of subsidence caused by the collapse of an underlying structure such as sinkholes in karst terrain.
• Sink: an endorheic depression generally containing a or intermittent lake, a salt flat or dry lake, or an ephemeral lake.
• Panhole: a shallow depression or basin eroded into flat or gently sloping cohesive rock.

• Sinkhole: a depression formed as a result of the collapse of rocks lying above a hollow. This is common in karst regions.
• Kettle: a shallow, sediment-filled body of water formed by melting glacial remnants in terminal moraines.
• Thermokarst hollow: caused by volume loss of the ground as the result of permafrost thawing.

• Impact crater: a depression created by an impact such as a meteorite crater.

• Sedimentary basin: in sedimentology, an area thickly filled with sediment in which the weight of the sediment further depresses the floor of the basin.

• Structural basin: a syncline-like depression; a region of tectonic downwarping as a result of isostasy or subduction.
• Graben or rift valley: fallen and typically linear depressions or basins created by rifting in a region under tensional tectonic forces.
• Pull-apart basin caused by offset in a strike slip or transform fault.
• Oceanic trench: a deep linear depression on the ocean floor. Oceanic trenches are caused by subduction of oceanic crust beneath either oceanic crust or continental crust.
• A basin formed by an ice sheet: an area depressed by the weight of the ice sheet resulting in post-glacial rebound after the ice melts

• Caldera: a volcanic depression resulting from collapse following a volcanic eruption.
• Pit crater: a volcanic depression smaller than a caldera formed by a sinking, or caving in, of the ground surface lying over a void.
• Maar: a depression resulting from phreatomagmatic eruption or diatreme explosion.