When all the fine dust and sand has been removed by deflation (wind and/or water erosion) a layer of stones is left behind called desert pavement.
Some beaches consist of coarse gravel. Shall I order fine or coarse gravel for the concrete walkway?
Desert pavement
desert gravel is just dried clay
Gravel grades for driveway construction typically range from fine to coarse. Common grades include fine gravel, medium gravel, and coarse gravel. Fine gravel is smaller in size and provides a smoother surface, while coarse gravel is larger and offers better drainage. Medium gravel falls in between the two in terms of size and is a popular choice for driveways.
The different gravel grades available for landscaping projects include fine gravel, medium gravel, and coarse gravel. Fine gravel is small in size, medium gravel is slightly larger, and coarse gravel is the largest. Each grade is used for different purposes in landscaping, such as pathways, driveways, or decorative accents.
I suggest you put the coarse gravel on top, the fine gravel in the middle and the cotton balls on the bottom. The less gaps in the material the more dirt will get trapped. The coarse gravel will take a small amount of the dirt out. Then the fine gravel will take out more and finally the cotton balls will most likely take out the rest leaving an evenly distributed amount of dirt in each layer. If the cotton balls are on top then the dirt would fill the cotton balls and some of it might still come through then the layers of gravel may not be effective to such small pieces of dirt.
Desert pavement
The amount of time that gravel can retain water will vary depending on its state. Fine gravel will holder water for long as opposed to coarse gravel.
of coarse if clean gravel.
Coarse aggregate can also be described as gravel, crushed rock, rocks or stones.
It becomes desert gravel still.
To effectively incorporate rock into a French drain system installation, place a layer of coarse gravel at the bottom of the trench before laying the perforated pipe. This gravel will help with drainage and prevent clogging. Additionally, surround the pipe with more gravel and top it off with a layer of filter fabric to keep out debris. This rock-filled design will enhance the drainage efficiency of the French drain system.