Organic materials
These materials are commonly associated with wetlands and are always dark in colour, usually black. Where positioned under wet anaerobic conditions will form peat. However, all forms of organic materials can only be confirmed with high confidence following laboratory testing for both organic matter and clay content. Some soils appear similar but have insufficient clay content to qualify as organic materials. They are commonly found to be more mineral rich Humose horizons.
Organosol, Tasmania
Photo credit: Department Of Primary Industries, Parks, Water And Environment, Tasmania