Redoximorphic Features
Redoximorphic features (RMFs) consist of color patterns in a soil that are caused by loss (depletion) or gain (concentration) of pigment compared to the matrix color, formed by oxidation/reduction of iron and/or manganese coupled with their removal, translocation, or accrual; or a soil matrix color controlled by the presence of iron (2+). The composition and responsible formation processes for a soil color or color pattern must be known or inferred before it can be described as an RMF.
Plinthite irreversibly hardens upon exposure to repeated wetting and drying, especially if exposed to heat from the sun. Other morphologically similar iron-rich materials that do not progressively harden upon repeated wetting and drying are not considered plinthite. The horizon in which plinthite occurs commonly has 2.5 percent (by mass) or more citrate dithionite extractable iron in the fine-earth fraction and a ratio between acid oxalate extractable Fe and citrate-dithionite extractable Fe of less than 0.10.
Upper photo:
Although distinct, the reddish redox concentrations in this image are not considered plinthite. Unlike plinthite, they could not be removed as a discrete body, and did not exhibit progressive hardening in the surrounding exposed road cuts and stream banks.
Lower photo:
Conversely, the red redox concentrations in this image are considered plinthite. They had a very firm rupture resistance, could be removed as a discrete body, and exhibited progressive hardening in the surrounding exposed road cut.
www.flickr.com/photos/jakelley/53407832443/in/dateposted-...
From a genetic viewpoint, plinthite forms by the segregation, transport, and concentration of iron. In many places iron may have been transported vertically or horizontally from other horizons or from higher adjacent soils.
For more information about a plinthic horizon, visit;
www.researchgate.net/publication/242649722_Rationale_for_...
or;
www.sciencedirect.com/science/article/pii/S00167061220043...
Redoximorphic Features
Redoximorphic features (RMFs) consist of color patterns in a soil that are caused by loss (depletion) or gain (concentration) of pigment compared to the matrix color, formed by oxidation/reduction of iron and/or manganese coupled with their removal, translocation, or accrual; or a soil matrix color controlled by the presence of iron (2+). The composition and responsible formation processes for a soil color or color pattern must be known or inferred before it can be described as an RMF.
Plinthite irreversibly hardens upon exposure to repeated wetting and drying, especially if exposed to heat from the sun. Other morphologically similar iron-rich materials that do not progressively harden upon repeated wetting and drying are not considered plinthite. The horizon in which plinthite occurs commonly has 2.5 percent (by mass) or more citrate dithionite extractable iron in the fine-earth fraction and a ratio between acid oxalate extractable Fe and citrate-dithionite extractable Fe of less than 0.10.
Upper photo:
Although distinct, the reddish redox concentrations in this image are not considered plinthite. Unlike plinthite, they could not be removed as a discrete body, and did not exhibit progressive hardening in the surrounding exposed road cuts and stream banks.
Lower photo:
Conversely, the red redox concentrations in this image are considered plinthite. They had a very firm rupture resistance, could be removed as a discrete body, and exhibited progressive hardening in the surrounding exposed road cut.
www.flickr.com/photos/jakelley/53407832443/in/dateposted-...
From a genetic viewpoint, plinthite forms by the segregation, transport, and concentration of iron. In many places iron may have been transported vertically or horizontally from other horizons or from higher adjacent soils.
For more information about a plinthic horizon, visit;
www.researchgate.net/publication/242649722_Rationale_for_...
or;
www.sciencedirect.com/science/article/pii/S00167061220043...