I was photographing in Upper Antelope Slot Canyon with a paid guide. He helped me find the changing light and other features. We stopped here and he threw sand up on these rocks to created a sand water fall. In this same location, there was falling sand coming down all around you. It was occurring naturally as the wind forced it from above...
I had to stand below an overhanging rock to protect me and my camera from being sand blasted while taking this and other images.