土壤剖面白板动画

A vertical cross-section of a soil profile, shown as a single rectangular block of earth cut away like a slice of cake. From top to bottom, exactly five layers in this order: a thin top layer of grass and fallen leaves; a dark brown topsoil layer with a few plant roots reaching into it; a lighter tan-coloured subsoil layer; a layer of broken rocks and gravel; and at the bottom solid grey bedrock. Clear boundaries between layers. Nothing else in the picture. Plain background with lots of empty space, 4:3. Coloured pencil and watercolour marker, clean black ink outlines, warm off-white paper, no text.