oduced but this was only a minor contributor to total atmospheric ozone Sand size (and larger) grams remained mostly in the lower levels of the Conohs storms Those closest to the surface caused severe erosion If the planet were not so geologically active (see ARRAKIS-GEOUXJY) its surface would have been entirely flat except for the ubiquitous dune fields During the decay phase of die storms much of the dust sealed back onto the surface Water vapor absorbed on the grains was earned downward also (a phenomenon locally called El Sayal) lomzation by ultraviolet rays gradually released the water back to the atmosphere Return was complete within a few days SURFACE EFFECTS Surface erosion from storms and the presence of dune fields are noted above The processes involved have been understood since antiquity and no elaboration is needed here However, the dust chasms (sometimes called tidal dust basins) and the drum sands merit special attention The chasms or basins were produced by geological processes, being subsequently filled with dust They were a hazard to unwary travelers because the dust had a quicksand* like behavior The dust packing was so under-dense that tidal motions much like oceanic tides were readily observable (locally called sandtides) The question of considerable scientific interest is why the dust should have exhibited almost negative packing, hence fluid-like behavior, since similar situations have rarely been found os any other planet We are indebted to Aster^k (15104) whose brilliant insight provided the final and correct answer by successfully producing the effect in the laboratory e The sequence of events is as follows a Dust deposited after each storm was highly charged Also, grain surfaces contained absorbed water vapor b The number of negative electrons and positive ions was initially about equal within the dust mass c The electrons attached themselves to the highly polar water vapor molecules d The water vapor molecules migrated upward along the atmospheric density gradient The ultraviolet rays then desorbed the water vapor, returning it to the atmosphere together with the negative charges e The positive ions were tightly bound to the distorted surface lattice of the dust grains and remained behind f As a result the dust had a strong and highly stable positive charge The repulsive electrostatic forces almost equaled the gravitational forces, hence the fluid-hke behavior g The dust layer built up m depressions and chasms after this fashion until they were filled Of course as the layer thickness increased, the weight of the overburden caused compaction Hence the quicksand like behavior was confined to the upper five meters (approximately) of the deposit The above phenomena were not observed in exposed areas since any charge inequality on dust deposited there was quickly neutralized by subsequent motion over the surface and prolonged exposure to ultraviolet Of course neutralized dust wa