What type of structural formation can be described as prismatic?

A prismatic structural formation refers to a column-like structure characterized by angular edges. This type of formation is typically seen in soil profiles where there is clear vertical development, often resulting from clay particle accumulation and swelling during wet conditions and shrinking during dry conditions. The angular edges of the prisms create distinct faces, which can readily be identified when looking at a soil sample.

The other choices do not fit the definition of prismatic structures. Flat, plate-like formations describe a different shape, often associated with platy structures that have a layered appearance, while loosely arranged particles would pertain more to granular formations that do not exhibit the angularity and vertical orientation of prisms. Additionally, irregular, block-like formations refer to structures that might have more random shapes without the distinct, columnar nature found in prismatic formations.