This is a melted soil: it’s a right and balanced mix of inorganic ( sand, silt and clay) and organic materials (plant and animal rests).
When it’s wet it forms, after compression, a little ‘ball’ . But it, easily, grinds.
This kind of soil permits roots to grow without obstacles. Sometimes we can find some stones, but they can be eliminated by hands, and in any case prove that there is an important sandy component.
Sand is a soil improvers.
Near stream it’s easy to find a part of silt: very nutrient for plants, even if it carrys a lot of weed seeds.
Clay permits to soil to ‘stay togheter’ and to plant to grow correctly.
Organic materials rapresent the ‘food’ for plants. It’s presence in quantity is tied by color: more it’s dark and more it’s rich in organic materials.