Geological Society of America

T54 Planetary Aeolian Geology from Outcrop to Orbit: Nathan Bridges Memorial Session

Sunday, 4 November 2018
1:30 PM - 5:30 PM
Room 136-137

THE ARGENTINEAN PUNA: AN AEOLIAN WONDERLAND AND PREMIER MARS ANALOG TERRAIN

Paper number: T54-7
Program: Technical Sessions
Time: 3:10 PM – 3:25 PM

Authors

Shanaka L. de Silva Presenting Author
Oregon State University, Corvallis, OR
Mauro Spagnuolo
UBA-CONICET, Buenos Aires
James R. Zimbelman
Smithsonian Institution, National Air and Space Museum, Washington, DC
Jonathan Patrick Perkins
Geology, Minerals, Energy, & Geophysics Science Center, Menlo Park, CA
Kirby D. Runyon
Applied Physics Laboratory, Laurel, MD
Ralph Lorenz
Johns Hopkins University, Laurel, MD
John Butkevicius
Austin Peay State University, Clarksville, TN

Abstract

A major problem in understanding the Martian aeolian system is determining how the interplay of fundamental physical factors (gravity, atmospheric density, frequency of winds above threshold, etc.) drive the formation of landforms that bear both commonalities and distinct differences with those on Earth. Many dunes and dust deposits have, to some degree, common analogs on Earth where they are better understood. In contrast, the origin of Martian megaripples and extensive sand-abraded landscapes, terrains that dominate much of the Martian surface, is less certain. A major hindrance to advancing our understanding of these Martian features and processes has been the lack of a suitable terrestrial analog where field measurements can inform formative conditions and rates on Mars. Recent work shows that the Argentinean Puna, which has been described as an aeolian geomorphology “perfect storm” may fill this gap. Here a bedrock lithology susceptible to aeolian sculpting dominates the surface of a wind-dominated hyper-arid, high-altitude, cold desert. This has resulted in a veritable aeolian wonderland dominated by yardangs, gravel megaripples, and bedrock ridges. Nathan Bridges was a key member of this team and we continue the work in his memory.

Our current work is informed by a series of questions, including:

What are the wind characteristics and required wind speeds that drive gravel movement?
What is the saltation regime that motivates the movement and accumulation of gravel bedforms?
What are the rates of migration and growth of gravel megaripples?
What do the transport paths of the gravel clasts look like and how is that related to the saltation and creep regimes?
How does the meter-scale topography of the bedforms impact wind regime, saltation regime and gravel megaripple formation
And, most importantly, what is the applicability and implications for Mars.

We will present an update of our recent efforts.

Geological Society of America Abstracts with Programs. Vol. 50, No. 6

doi: 10.1130/abs/2018AM-321918

© Copyright 2018 The Geological Society of America (GSA), all rights reserved. Permission is hereby granted to the author(s) of this abstract to reproduce and distribute it freely, for noncommercial purposes. Permission is hereby granted to any individual scientist to download a single copy of this electronic file and reproduce up to 20 paper copies for noncommercial purposes advancing science and education, including classroom use, providing all reproductions include the complete content shown here, including the author information. All other forms of reproduction and/or transmittal are prohibited without written permission from GSA Copyright Permissions.