Layer Analysis

I moved deeper into the park, past the gravel path toward a low brick retaining wall. A patch of dried moss clung to the mortar line between two red bricks. I rested the pickaxe head lightly against the brick face and wedged the pointed pick into the crumbly seam. A crisp flake of dry green moss peeled away in one intact strip, exposing a layer of powdery, sand-colored mortar underneath. I collected the detached strip and laid it flat across the top ledge to observe its uniform porous underside. The boundary between vegetation and masonry is cleanly stratified.