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Gravelly sediments are clastic sediments containing rock fragments larger than 2 millimeters (0.08 inches) in diameter. These fragments can be rounded or angular, depending on the transportation and deposition processes.

Nonmarine settings refer to locations on earth that are not influenced by marine (oceanic) environments. These include terrestrial and freshwater settings.

Gravelly sediments can accumulate in a variety of nonmarine environments. Some common settings where gravelly sediments often accumulate are: 1. River channels: Gravel can be found in and alongside rivers, especially along the bends or downstream from a river's source. Erosion from the riverbanks and underlying bedrock contribute to the production of these gravelly sediments, which are then transported by the river's flow. 2. Alluvial fans: Alluvial fans are cone-shaped deposits of gravel, sand, and silt that accumulate at the base of mountain ranges. They form where a river or stream emerges from a steep slope onto a flat plain, causing the flow to slow down and deposit its load of sediments. 3. Glacial environments: Glaciers are large masses of ice that move slowly across the land, eroding the underlying bedrock and generating large amounts of gravelly sediments. These sediments are then transported by the glacial movement and/or meltwater outwash and deposited in various glacial landforms, such as moraines, outwash plains, and eskers. 4. Landslide deposits: Landslides, or mass wasting events, can generate gravelly sediments when large volumes of rock and soil on slopes become unstable and flow downhill. The resulting chaotic mixture of debris can include a range of sediment sizes, including gravels.