Reference soil Costa Rica 10: Fluvisol
CR010
Fluvisols typically are young soils in alluvial, deltaic, lacustrine, or marine deposits, and occur all over the world.
Characteristics
Soils having fluvic soil material starting within 25 cm from the soil surface and continuing to a depth of at least 50 cm from the soil surface. They have no diagnostic horizons other than a histic, mollic, ochric, takyric, umbric, yermic, salic, or sulfuric horizon.
Distribution of Fluvisols (rough estimation supplied by soilgrids)
Reference soil CR010: Fluvisols
presence of cutans is not so convincing. Note: "halloysite" in clay mineralogy is mixture of 0.7 and 1.0 nm material.