Which process governs the formation of fining-upward alluvial successions in sedimentary basins?

💡 Explanation

When flow deposits alluvium under gradually reduced energy transport, grains are fractionated because settling velocity sorts coarse, then fine particles as river competency wanes, leading to a fining-upward sequence. Thus decreasing flow competence deposits alluvium in layers, rather than oscillations, subsidence or base-level shifts which would create more varied patterns.

• Which effect increases when riverine levees constrict floodplains subjected to increased precipitation?
• Which process exacerbates desertification when ephemeral streams deposit sediment on alluvial fans?
• Which outcome occurs when deforestation exposes streambeds extensively?
• Which erosional outcome occurs where strike-slip motion terminates along transform boundaries between oceanic plates?
• Which mechanism causes meandering stream formation across flat plains undergoing regional uplift?
• Which risk increases for structures founded upon unstable alluvial soils?