illuvia
/ɪˈluːviə/
noun
- Materials, such as clay or minerals, that are washed from one layer of soil and deposited in another layer below.
- The illuvia in the lower soil layers made the ground rich in nutrients for deep-rooted plants.
- Farmers noticed that the illuvia had created a hardpan layer that prevented water from draining.
- Geologists studied the illuvia to understand how the landscape had changed over thousands of years.