direction of flow in sludgy foam patterns and contours in the thick sludge on the edge of mineral lake of a meteorite crater

african air background bottom bubbles bubbling close collection contours crater darkened deposit deposits detail direction dirty discoloration edge flow foam foamy image lake light lines meteorite mineral mineralized natural nature patterns salt saturated scum sediment silt sludge sludgy south streaks surface texture thick tshwaing verge view washing water wet white