Which process initiates the formation of an alluvial fan deposit in arid regions?

💡 Explanation

When a stream exits a channel onto a plain, flow velocity decreases rapidly because of reduced confinement and slope, causing sediment deposition, therefore initiating alluvial fan formation, rather than sheetwash, glacial action or active tectonic uplift, which each create different geomorphological features.

• Which mechanism accelerates the melting of permafrost when organic matter thaws in previously frozen soils?
• Which effect characterizes stream morphology along an active transform fault boundary?
• Which long-term outcome arises when intense chemical weathering of basalt releases soluble cations in tropical lateritic systems?
• Near a large quarry, which outcome results when groundwater acidity increases beyond limestone dissolution equilibrium?
• Which risk increases during prolonged flooding of alluvial plains containing fine silt deposits?
• Which mechanism causes consistent surface wind patterns within Hadley cells?