Click to enlarge. Brunisols have enough horizon development to exclude them from Regosols but lack sufficient development required for other soil orders. Brunisolic soils can be viewed as a stage in an evolutionary sequence that begins with an unweathered parent material (Regosolic soils) and ends with development of a “mature” soil (e.g., of the Podzolic or Luvisolic orders). Several horizon types are used as diagnostic horizons for the Brunisolic order (although all must be at least 5 cm thick). The main horizon associated with the Brunisolic order is the Bm horizon (a horizon that has undergone minimal pedogenic alteration), while others include Bfj, Btj, and Bhjfj.