Soil Genesis – Water-Formed Transported Soils (Identify the Best Example) Which of the following is a soil type predominantly formed and transported by running water?

Introduction / Context:
Soil deposits are often classified by the transporting medium: water, wind, ice, or gravity. Recognizing the genesis helps anticipate grading, fabric, compressibility, and engineering properties.

Given Data / Assumptions:

• Focus on a representative example of water-transported soils.
• Single-best-answer format.

Concept / Approach:

Running water in rivers produces alluvial soils—layered sands, silts, and clays along floodplains, deltas, and terraces. Marine soils are laid in seas (still water with tides), lacustrine soils in lakes (quieter water), while loess is wind-blown silt and not water-transported.

Step-by-Step Solution:

Verification / Alternative check:

Geology texts consistently define alluvium as river-laid material; the stratification and sorting by flow support this identification.

Why Other Options Are Wrong:

Marine and lacustrine are also water-laid but not specifically by running river flow; the question emphasizes transported by running water. Loess is aeolian (wind), not water-laid.

Common Pitfalls:

Assuming all water-laid deposits are equivalent; ignoring the different hydrodynamics of rivers vs seas/lakes that affect fabric and properties.

Final Answer:

Alluvial