Ortstein: Odd couple--Ortstein aggregate and plinthite nodules in same soil
Often you can learn a lot about soils by simply observing exposed materials as these ortstein aggregates and plinthite nodules exposed on an eroded soil surface.
Ortstein is part of a spodic horizon. When moist, it is at least weakly cemented into a massive horizon that is present in more than half of each pedon. Ortstein forms in acid sandy soils where pines are the dominant vegetation. The acidity puts organic acids, aluminum and sometimes iron into solution. A high water table prevents the downward movement of the dissolved chemicals, which then cement the soil particles together.
Plinthite is an iron-rich, humus-poor mixture of clay with quartz and other minerals. Plinthite is a redoximorphic feature in highly weathered soil. The product of pedogenesis, it commonly occurs as reddish redox concretions that usually form platy, polygonal, or reticulate patterns in the soil. Plinthite changes irreversibly to an ironstone or to irregular soil aggregates on exposure to repeated wetting and drying, especially if it is exposed to heat from the sun.
For more information about a plinthic horizon, visit;
www.researchgate.net/publication/242649722_Rationale_for_...
or;
www.sciencedirect.com/science/article/pii/S00167061220043...
Ortstein: Odd couple--Ortstein aggregate and plinthite nodules in same soil
Often you can learn a lot about soils by simply observing exposed materials as these ortstein aggregates and plinthite nodules exposed on an eroded soil surface.
Ortstein is part of a spodic horizon. When moist, it is at least weakly cemented into a massive horizon that is present in more than half of each pedon. Ortstein forms in acid sandy soils where pines are the dominant vegetation. The acidity puts organic acids, aluminum and sometimes iron into solution. A high water table prevents the downward movement of the dissolved chemicals, which then cement the soil particles together.
Plinthite is an iron-rich, humus-poor mixture of clay with quartz and other minerals. Plinthite is a redoximorphic feature in highly weathered soil. The product of pedogenesis, it commonly occurs as reddish redox concretions that usually form platy, polygonal, or reticulate patterns in the soil. Plinthite changes irreversibly to an ironstone or to irregular soil aggregates on exposure to repeated wetting and drying, especially if it is exposed to heat from the sun.
For more information about a plinthic horizon, visit;
www.researchgate.net/publication/242649722_Rationale_for_...
or;
www.sciencedirect.com/science/article/pii/S00167061220043...