From a genetic classification standpoint, the alluvial soils occupying the vast Ganga plains are considered _________.

Alluvial soils are classified as azonal soils because they are relatively young, immature, and lack well-developed soil horizons ($A$, $B$, $C$). They are formed primarily due to the continuous deposition of sediments carried by river systems rather than long-term localized in-situ weathering influenced predominantly by regional climate or parent rock.