Multistage Evolution in Transverse Aeolian Ridges

Timothy Nagle-Mcnaughton,Louis Scuderi

doi:10.3390/rs13071329

Abstract

Transverse aeolian ridges (TARs) are poorly understood relict aeolian Martian surface features. Processes that create TARs are not well-constrained, and understanding their formation is complicated since they appear to share some features of ripples, megaripples, and dunes. While some evidence of multi-stage TAR formation has been documented in Nirgal Vallis, here we present additional evidence for this process at nine locations on Mars using cratering superposition between different ridge morphologies. Most occurrences of multistage evolution will not preserve the precise series of cratering and formation events documented here, which potentially means that this formative process may have been more common than even these new widespread observations suggest. This formative process can help determine the relative similarity of TARs to ripples, megaripples and dunes. Based on our observations, we conclude that primary TAR forms are most like megaripples, and that subsequent ridges formed like aqueous ripple spurs.

Highlights

While some evidence of multi-stage Transverse aeolian ridges (TARs) formation has been documented in Nirgal Vallis, here we present additional evidence for this process at nine locations on Mars using cratering superposition between different ridge morphologies
We conclude that primary TAR forms are most like megaripples, and that subsequent ridges formed like aqueous ripple spurs
We present new evidence for the multi-stage formation of TARs on Mars using the superpositioning of craters within different aeolian ridge morphologies

Summary

Introduction

While TARs are widespread on Mars, their role in past Martian sediment cycles is poorly understood [2,3,4,5,6,7]. TAR morphologies are typically categorized by a single primary ridge crest, but secondary ridge crests have been observed [2,13,14]. These secondary ridges remain largely unexplained [2,3,14], they display similarities to raked linear dunes [15,16]

Methods

Results

Discussion

Conclusion