Plate XI — Erosion

Structural intent

Show material transformation under repeated environmental action: wear, smoothing, abrasion, chipping, and patina as a record of exposure.

What must be observable

• Surface change that indicates repeated action (weathering, rounded edges, pitting).
• Material continuity: the same base material shows different wear levels.
• Record-like variation (exposed vs protected areas).
• A credible causal mechanism (wind/water contact, foot traffic paths, abrasion zones).

Common failure modes

• “Dirty” or noisy texture without wear mechanics.
• Postprocessing/grain mistaken for erosion evidence.
• Damage that looks like discrete breakage rather than gradual action.
• Inconsistent wear patterns that lack exposure logic.

UI / system translation (non-symbolic)

• Use for “system drift,” reliability, and maintenance narratives.
• In UI: degradation indicators, lifecycle states, stability confidence.
• In system terms: SLO burn, error budgets, maintenance windows, progressive decay models.
• QA: require visible edge wear and exposure-gradient cues.