renormalised
22-07-2011, 06:06 PM
Very interesting article in nature about the determination of the thermal history of Mars as derived from a mineralogical study of it's volcanic provinces. They used the gamma ray spectrometer on Mars Odyssey to determine the mineralogy present and therefore the thermal and dynamic history of the planet.
If you'd like the article, I'll have to email it as it's too big to attach to this post
They used an application called Melts/pMelts to generate phase diagrams (P-T-t and P-F) for the mineralogy found in the 12 volcanic provinces they studied. You can use these phase diagrams to plot the changes in temperature, pressure and partial melting of the rocks you're studying. How they do this is to look at certain chemical phases that are present within the minerals and then determine the ratios of those phases to one another, to derive the P, T and F values. Certain chemical phases within minerals, such as FeO, SiO2, Fe2O3, Al2O3 etc etc are sensitive to the pressure and temperature at which they form and by determining the ratios between these chemical phases you can get an accurate picture of what P and T the rocks formed at. You can also look at trace elements to determine the P-T paths and the origins of the rocks as well. Some trace elements are more than likely to turn up in certain rocks than others due to the characteristics of the chemistry of those trace elements.
If you have any questions about the article, just ask:)
If you'd like the article, I'll have to email it as it's too big to attach to this post
They used an application called Melts/pMelts to generate phase diagrams (P-T-t and P-F) for the mineralogy found in the 12 volcanic provinces they studied. You can use these phase diagrams to plot the changes in temperature, pressure and partial melting of the rocks you're studying. How they do this is to look at certain chemical phases that are present within the minerals and then determine the ratios of those phases to one another, to derive the P, T and F values. Certain chemical phases within minerals, such as FeO, SiO2, Fe2O3, Al2O3 etc etc are sensitive to the pressure and temperature at which they form and by determining the ratios between these chemical phases you can get an accurate picture of what P and T the rocks formed at. You can also look at trace elements to determine the P-T paths and the origins of the rocks as well. Some trace elements are more than likely to turn up in certain rocks than others due to the characteristics of the chemistry of those trace elements.
If you have any questions about the article, just ask:)