The formation and evolution of the Martian mantle: a Martian meteorite perspective

Mari, Nicola (2020) The formation and evolution of the Martian mantle: a Martian meteorite perspective. PhD thesis, University of Glasgow.

Abstract

Revealing the internal composition and evolution of the terrestrial planets is crucial to understanding planetary evolution in the Solar System and beyond. Mars is a perfect source of this information, since its mantle was not homogenized after the earliest phases of planetary differentiation. However, the interior evolution and composition of Mars is still unknown. Martian meteorites are the only rock samples from Mars that are available on Earth. The aim of this research is to obtain new insights about Martian mantle formation and its evolution from the perspective of the Martian meteorites. In particular, this work is divided into three interdisciplinary investigations in order to obtain new constraints on our knowledge about the Martian mantle. Firstly, the Tissint Martian meteorite was investigated since it is the meteorite that is most representative of the Martian mantle. This meteorite was analysed with the objective of obtaining information about the thermal state and convective activity in the Mars’ mantle. Major- and trace-element data for Tissint olivine and pyroxene were reported, and these data were used to provide new insights into the dynamics of the Tissint magma chamber, as well as the dynamics and temperature of Martian mantle at the time of Tissint crystallisation. Secondly, the potential for chemical tracing of the different Martian mantle sources was investigated by analysing rhenium-osmium and sulphur isotope compositions in five of the ten known nakhlite lava flows (Nakhla, Lafayette, MIL 090032, Yamato 000593, and Yamato 000749). In addition, these findings were used to suggest a plausible scenario to account for nakhlite magma origins. These findings were also utilised to discuss the implications of this work for fingerprinting the processes responsible for setting Martian mantle compositions during late-stage crystallization of a Martian magma ocean. Thirdly, the abundance of the volatile element chlorine in the Martian mantle was calculated by analysing amphibole and apatite phases in the two shergottites Tissint and Zagami. After finding that these phases record magmatic conditions of the Martian interior, the partition coefficients between chlorine and the parent melt were used to estimate the chlorine abundance of the shergottite magma source. In sum, the importance of the combined new findings are presented to explore their implications for our understanding of Mars’ formation and evolution and, more generally, the evolution of terrestrial planets.

• Item Type: Thesis (PhD)
• Qualification Level: Doctoral
• Keywords: martian meteorites, martian mantle, martian magmatism, martian volcanology, martian geochemistry, planetary formation, planetary evolution
• Subjects: Q Science > QE Geology
• Colleges/Schools: College of Science and Engineering > School of Geographical and Earth Sciences > Earth Sciences
• Supervisor's Name: Hallis, Dr. Lydia J.
• Date of Award: 2020
• Depositing User: Nicola Mari
• Unique ID: glathesis:2020-81314
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 20 May 2020 16:22
• Last Modified: 08 Sep 2022 16:13
• Thesis DOI: 10.5525/gla.thesis.81314
• URI: https://theses.gla.ac.uk/id/eprint/81314