Abstract by Jonathon Sevy
FIELD OBSERVATIONS OF YARDANGS IN THE ARGENTINE PUNA: WHAT DEDOS AND CAP SLOPES REVEAL
Yardangs are wind-carved linear ridges that are found selectively on Earth and extensively on Mars and other planets. The history of the morphologic development of yardangs is not well known. In the Puna high plateau of Argentina there are intruded volcanic ash deposits, many of which have been eroded into yardang fields commonly called fleets. These are composed of roughly tear-drop shaped, evenly-spaced ridges with noses that face into the dominant wind, that together resemble a fleet of boats sailing. A prominent fleet, known as Campo de Piedra Pomez (CCP), was studied in December 2018 and 2019 to more fully understand their morphology and formation. Wind indicators called dedos, and other structural features were measured through a transect of the CPP and analyzed. It was found that the yardangs had increasing forward dedos toward the front of the fleet, and increasing reverse dedos toward the back of the fleet. This indicates a second wind from an opposing direction. Wind indicators also reveal that this opposing wind is coming from a west/southwest direction, rather than a complete 180° southeast.