The phrase "a layer of mud" is correct and usable in written English.
It can be used to describe a physical layer of mud, often in contexts related to nature, construction, or environmental conditions.
Example: "After the heavy rain, the garden was covered with a thick layer of mud that made it difficult to walk through."
Alternatives: "a coating of mud" or "a film of mud".
Dr. Wright's team gathered DNA from a layer of mud about 20 feet beneath the surface.
"We're just trying to clean up a layer of mud from the floor.
After being temporarily incapacitated by an electric fence, he stumbled to his feet, shook off a layer of mud and manure, and trudged on.
The floodwater left a layer of mud in the first-floor offices of Dr. Jairo Rendon, a dentist, and destroyed the towels, toothbrushes, gloves and cups he had stored in the basement.
In the warm, dry climates of the river valleys, weathering action was not a major problem, and the mud bricks were left exposed or covered with a layer of mud plaster.
It shows that a layer of mud cake will be firstly attached on the screen during the experiment.
The 40-story-tall platform and its 28 drilled wells were buried under a layer of thick mud.
The echoes may also show other objects, such as schools of fish, or they may reveal the dual nature of the bottom, where a layer of soft mud may overlie rock.
Topped by a layer of dried mud, the squat bulletlike block of weathered wood that is "For Beckwourth" (1980) conjures up an Indian lodge, a Baule sculpture coated with dried sacrificial material, an early Greek tomb and a nondenominational church dome.
After the event, a layer of dense mud, between 200 and 400 mm thick, covered an overall area of 43.5 ha over a length of 4200 m (Genevois and Tecca 1993; Van Niekerk and Viljoen 2005).
Walls were then covered in a veneer of small sandstone pieces, which were pressed into a layer of binding mud.
