Records of ancient climate change on mars: investigating sedimentary successions in gale crater & oxia planum
File(s)
Author(s)
Roberts, Amelie Louise
Type
Thesis
Abstract
A central goal of Mars exploration has been to understand how the climate evolved from one that once supported liquid water to the cold, hyperarid desert observed today. This thesis examines the sedimentary geology and geomorphology of two regions on Mars from during and after the Noachian-Hesperian boundary, when surface water activity was thought to have waned. The overarching objective is to evaluate how the sedimentary environments of these regions evolved through time and the implications for regional climate change. The first study area, the basal section of the orbitally defined Layered Sulfate unit (LSu) in Gale crater, was explored in situ by the Curiosity rover. The second study area, the sediment fan at Oxia Planum, lies within one of the proposed landing ellipses of the upcoming Rosalind Franklin rover.
At Gale crater, rover and orbital datasets are used to investigate the lithofacies and sedimentary architecture of the basal section of the LSu. Two studies are presented. The first documents decametre-wide scour-and-fill structures, interpreted as aeolian, providing evidence for a period of intensified wind activity. The second examines the ~100 m basal succession, where the lithofacies are consistent with a predominantly aeolian environment, with thick sandsheets likely controlled by near-surface water. Together, these results suggest that groundwater and habitable conditions may have persisted longer than simple aridification models imply.
At Oxia Planum, high-resolution orbital datasets are used to reconstruct the geomorphology and photogeology of the sediment fan. The results reveal Re. These observations constrain the timing and longevity of aqueous activity in the Oxia basin and provide context for future rover exploration.
Collectively, this thesis demonstrates how late-stage aqueous processes shaped Martian sedimentary environments and highlights the importance of integrating rover and orbital datasets for understanding past habitability.
At Gale crater, rover and orbital datasets are used to investigate the lithofacies and sedimentary architecture of the basal section of the LSu. Two studies are presented. The first documents decametre-wide scour-and-fill structures, interpreted as aeolian, providing evidence for a period of intensified wind activity. The second examines the ~100 m basal succession, where the lithofacies are consistent with a predominantly aeolian environment, with thick sandsheets likely controlled by near-surface water. Together, these results suggest that groundwater and habitable conditions may have persisted longer than simple aridification models imply.
At Oxia Planum, high-resolution orbital datasets are used to reconstruct the geomorphology and photogeology of the sediment fan. The results reveal Re. These observations constrain the timing and longevity of aqueous activity in the Oxia basin and provide context for future rover exploration.
Collectively, this thesis demonstrates how late-stage aqueous processes shaped Martian sedimentary environments and highlights the importance of integrating rover and orbital datasets for understanding past habitability.
Version
Open Access
Date Issued
2025-09-16
Date Awarded
2026-06-01
Copyright Statement
Attribution-NonCommercial 4.0 International Licence (CC BY-NC)
License URL
Advisor
Gupta, Sanjeev
Davis, Joel
Banham, Steven
Fawdon, Peter
Sponsor
Science and Technology Facilities Council (Great Britain)
Grant Number
ST/W507520/1
Publisher Department
Department of Earth Science & Engineering
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)