M.D. Fries

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The source and nature of carbon on Mars have been a subject of intense speculation. We report the results of confocal Raman imaging spectroscopy on 11 martian meteorites, spanning about 4.2 billion years of martian history. Ten of the meteorites contain abiotic macromolecular carbon (MMC) phases detected in association with small oxide grains included(More)
We report on the detection of discrete grains of crystalline graphite and graphite whiskers (GWs) in an Apollo 17 impact melt breccia. Multiple instances of graphite and GWs within a discrete area of the sample imply that these grains are not terrestrial contamination. Both graphite and GWs are indicative of high-temperature conditions and are probably the(More)
Introduction: Products of low-T aqueous alteration processes on Mars are relatively abundant in the nakhlites [1]. This includes mixtures of poorly crystalline clays and amorphous material, often dubbed id-dingsite. They can be found in the mesostasis or forming veinlets in olivine [2] as well as being part of mineral assemblages, e.g. inside carbonate(More)
The utility of nondestructive laser Raman for testing the biogenicity of microfossil-like structures in ancient rocks is promising, yet results from deposits like the ∼3.46 Ga Apex chert remain contentious. The essence of the debate is that associated microstructures, which are not purported to be microfossils, also contain reduced carbon that displays(More)
Introduction. The Stardust spacecraft collected dust samples of the Kuiper belt comet 81P Wild-2 in aerogel and returned them to Earth January 15, 2006. Preliminary examination (PE) of the collected dust will include teams focused on mineralogy [1], chemical composition [2], isotopic measurements [3], organic analysis [4], cratering [5] and spectroscopic(More)
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