Explore the mineralogy of Mars through a 24-minute talk by Harry McSween from the University of Tennessee, Knoxville. Delve into the analysis of Martian meteorites and their unique characteristics, including shock-implanted gases matching Mars' atmospheric composition and distinctive oxygen isotopic fingerprints. Examine how these meteorites constrain the planet's bulk composition, volatile inventory, and mantle sources. Compare findings from meteorites with data collected by Mars rovers, revealing differences in mantle source compositions. Investigate the absence of calc-alkaline rocks and Earth-like continental crust on Mars, suggesting a lack of plate tectonics. Gain insights into the planet's basaltic nature and the diverse ancient mantle sources reflected in its sediments and cumulates.
Overview
Syllabus
Intro
The mineralogy of Mars, from 125 rocks in hand
Martion meteorites contain shock-implanted gas that matches the unique Mars atmospheric composition
Unique, ancient martian meteorites
Meteorite element ratios constrain the bulk planet composition and volatile inventory
Meteorites indicate Mars has a unique and diagnostic oxygen isotopic fingerprint
Martian meteorites formed by melting of ancient mantle sources with distinct radiogenic isotopes, trace elements, and redox states
Trace elements are both depleted and enriched
Igneous crystallization oges vary, but are mostly young
Cosmic-ray exposure ages are interpreted to date times of ejection from Mars
How representative of Mars are martian meteorites?
Martian meteorites and rocks analyzed by rovers
Trends in minor elements indicate different mantle source compositions for meteorites and rover analyzed rocks
Absence of any calc-alkaline rocks indicates no crustal recycling by plate tectonics
No detectable granitic rocks, just feldspathic rocks
No Earth-like continental crust on Mars
Despite much odo about purported evidence for life in ALH 84001, its organic matter, minerals, and intriguing
Conclusions Mars is a basalt covered world with sediments derived from cumulates that reflect diverse ancient mantle sources
Taught by
Mineralogical Society of America
