Just as former Cyclone Gita hit New Zealand with heavy rains, extreme winds, and huge waves, a unexpected phenomenon was caught around the Rakaia Gorge by Joe Todhunter and Donna Field. These lucky trekkers witnessed an impressive river of stones riding down the hill toward the sea, or better said, the formation of a shingle fan. Often called a quasi liquid flow these rocks are travelling like a river from the mountains to be deposited in a fan shape where the land flattens out. Baffling!
I have never witnessed such a phenomenon. Totally unexpected!