In the crystalline Basement Complex terrain of Southwestern Nigeria, soil characteristics vary systematically along a hillslope profile (soil catena). Arrange the following soil types/zones in the correct order from the hilltop (summit) down to the valley bottom.
- 1Shallow, gravelly lithosols formed on exposed rocky inselberg summits and steep crests.
- 2Deep, well-drained reddish-brown Ferruginous soils on stable upper pediment slopes.
- 3Medium-textured colluvial soils accumulated along gentle lower pediment slopes.
- 4Seasonally waterlogged, greyish hydromorphic clay soils (Fadama) in the valley depression.
Answer
The correct catenary sequence from hill crest to valley bottom is: Shallow lithosols on crests → Deep reddish Ferruginous soils on upper slopes → Colluvial soils on lower pediment slopes → Hydromorphic clay soils (Fadama) on the valley floor.
In Nigerian Basement Complex landscapes, relief dictates drainage, soil depth, and moisture regimes along a catenary gradient. The sequence begins at the crest with shallow lithosols due to runoff, moves to well-drained deep Ferruginous soils on upper pediment slopes, transitions to colluvial deposits on lower slopes, and terminates in waterlogged hydromorphic clay soils in valley bottoms.
Step-by-Step Solution
Key Concept
Soil Catena and Topographic Control on Nigerian Soil Distribution
Estimated Time:2m 0s