Ironstone concretion interior
Concretions are strongly or more cemented bodies that do not disaggregate in water and are similar to nodules except for the presence of visible concentric layers of material around a point, line, or plane. The terms "nodule" and "concretion" are not interchangeable.
The distinction between cemented materials is important for engineering applications. Materials that are very strongly or more cemented are considered suitable as road base or construction materials, whereas lesser cemented materials disintegrate as strong pressure is applied.
A simple test is to place the material on a solid surface and apply full body weight. Very strongly or more cemented materials will remain intact without crushing.
Note: The materials below a lithic contact (rock) must be in a strongly or more cemented Rupture Resistance Class. The hard fragments (e.g., rock) have a Rupture Resistance Cementation Class that is strongly or more cemented. If the soil has paralithic contact, the softer fragments (e.g., pararock) are cemented, but less than strongly cemented. Should these same naming conventions be applied to cemented pedogenic materials?
As a general rule, this has been done, e.g., a soil with 25 percent, by volume, plinthite nodules described as having a "paragravelly" texture modifier or a soil with 25 percent, by volume, ironstone concretions described as having a "gravelly" texture modifier.
For more information about describing and sampling soils, visit:
www.nrcs.usda.gov/resources/guides-and-instructions/field...
For additional information on "How to Use the Field Book for Describing and Sampling Soils" (video reference), visit:
www.youtube.com/watch?v=e_hQaXV7MpM
For additional information about soil classification using USDA-NRCS Soil Taxonomy, visit:
www.nrcs.usda.gov/resources/guides-and-instructions/keys-...
or;
www.nrcs.usda.gov/resources/guides-and-instructions/soil-...
For more information about the major principles and practices needed for making and using soil surveys and for assembling and using related soils data, visit:
www.nrcs.usda.gov/resources/guides-and-instructions/soil-...
Ironstone concretion interior
Concretions are strongly or more cemented bodies that do not disaggregate in water and are similar to nodules except for the presence of visible concentric layers of material around a point, line, or plane. The terms "nodule" and "concretion" are not interchangeable.
The distinction between cemented materials is important for engineering applications. Materials that are very strongly or more cemented are considered suitable as road base or construction materials, whereas lesser cemented materials disintegrate as strong pressure is applied.
A simple test is to place the material on a solid surface and apply full body weight. Very strongly or more cemented materials will remain intact without crushing.
Note: The materials below a lithic contact (rock) must be in a strongly or more cemented Rupture Resistance Class. The hard fragments (e.g., rock) have a Rupture Resistance Cementation Class that is strongly or more cemented. If the soil has paralithic contact, the softer fragments (e.g., pararock) are cemented, but less than strongly cemented. Should these same naming conventions be applied to cemented pedogenic materials?
As a general rule, this has been done, e.g., a soil with 25 percent, by volume, plinthite nodules described as having a "paragravelly" texture modifier or a soil with 25 percent, by volume, ironstone concretions described as having a "gravelly" texture modifier.
For more information about describing and sampling soils, visit:
www.nrcs.usda.gov/resources/guides-and-instructions/field...
For additional information on "How to Use the Field Book for Describing and Sampling Soils" (video reference), visit:
www.youtube.com/watch?v=e_hQaXV7MpM
For additional information about soil classification using USDA-NRCS Soil Taxonomy, visit:
www.nrcs.usda.gov/resources/guides-and-instructions/keys-...
or;
www.nrcs.usda.gov/resources/guides-and-instructions/soil-...
For more information about the major principles and practices needed for making and using soil surveys and for assembling and using related soils data, visit:
www.nrcs.usda.gov/resources/guides-and-instructions/soil-...