noun
1 : clay, silt, sand, gravel, or similar detrital material deposited by running water
The irate baron’s clothing was covered in various alluvia by the time he climbed bak out of the riverbank.
This is almost another word for older diction, but you notice it covers all kinds of things that water displaces. I think this’ll make it handy for when you have to point out something other than just silt or clay.